Simon Hill On Proving Plant-Based Diet Positives

Beyond politics and religion, few topics are more hotly debated than nutrition. But when we consider the totality of health—not just human health, but planetary, ecosystem, soil, and animal well-being—the science is irrefutable: a diet that is as plant-exclusive as possible is best. Nonetheless, misinformation fueled by emotions and ideological tribalism persists. Confusion propagates. Thus the average well-intentioned person remains stuck in unhealthy lifestyle habits that tragically lead to avoidable ailments and disease. Meanwhile, the planet suffers. To help us parse facts from fiction and guide us towards an evidence-based, rational model for nutritional health and well-being, today we convene with my friend Simon Hill. The host of the fantastic Plant Proof Podcast and blog of the same name, Simon plies his master’s degree in nutrition to objectively decipher scientific literature to deliver clear and actionable tools to help people make diet and lifestyle choices that actually promote optimal health and longevity. The culmination of Simon’s obsession with nutritional science is The Proof Is In The Plants,the ultimate evidence-based primer on the positive impact of a plant-based diet on human and planetary health—and an essential must-read for any and all interested in grounded nutrition science. Today we hit all the hot topics: tribal diet wars, what the science says and what it doesn’t, the environmental implications of our food choices, the truth about saturated fat, cholesterol, and oil. Not to mention the key things you can and should be doing to perform at your peak, sidestep disease, promote longevity, and live both optimally and consciously. To read more click here. You can also watch listen to our exchange on YouTube. And as always, the podcast streams wild and free on Apple Podcasts and Spotify. For so many reasons, Simon is the health and nutrition resource we need right now—and this one is packed with crucial, perhaps life-saving information. Break out pen and paper—you’re going to want to take notes. Final Note: Simon was kind enough to provide comprehensive evidentiary support for his many statement throughout the podcast. For those that desire to to dig deeper into the science, click the ‘References’ tab on this episode's web page here. Peace + Plants, Rich Learn more about your ad choices. Visit podcastchoices.com/adchoices

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Rich Roll?

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• 0:44Rich Roll?

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• 1:06Simon Hill?

  The sort of general school of thought is that you get your protein from animal foods, and that plants are missing protein. And that's not true. All plants contain all nine essential amino acids. I'm big on diet quality being more important than focusing too much on the macronutrients. The macronutrients can be important if you have a very specific goal, but I think what's more important first is the quality of those macronutrients, the quality of the fat, the quality of the carbohydrates. You know, it's less jelly beans, more black beans. In terms of strength and building muscle, this is a really interesting area, and there's a lot of emerging science here.

• 1:51Simon Hill?

  And I'm starting to see nutrition scientists in this space who have been very adamant that animal protein is king, starting to change their tune a bit. And, you know, I don't think it's all sort of said and done, but there is some early clues that you can still get the same benefits in terms of strength and hypertrophy from consuming plant protein.

• 2:30Rich Roll?

  Very few topics are more hotly debated than nutrition. It truly is right up there with politics and religion. But the irony is that the hard science, which we're going to get into today in depth, is actually pretty clear. Nonetheless, misinformation persists fueled by emotions, by ideological tribalism, in a manner that propagates not only confusion, but paralysis, keeping the average well-intentioned person stuck in unhealthy lifestyle habits that often, and quite tragically, lead to avoidable ailments and disease.

• 3:11Rich Roll?

  To help us parse fact from fiction and guide us towards a reasoned, rational model for nutritional health and wellbeing, today we convene with my friend, Simon Hill. Simon is the host of the fantastic Plant Proof podcast and blog of the same name, both incredible resources, and he applies his master's degree in nutrition to objectively decipher the scientific literature to help people make better diet and lifestyle choices to promote optimal health and longevity. Simon is also the plant-based food contributor to Chris Hemsworth's fitness app, Center. He owns the best plant-based restaurant in Sydney, Australia, Eden, which is a must

• 3:56Rich Roll?

  if you find yourself in Bondi Beach. And he is the author of a fantastic new book, The Proof is in the Plants, which, no hyperbole, is the ultimate essential evidence-based primer on the positive impact of a plant-based diet on human and planetary health. A few more important items to mention before we get into it, but first.

• 4:24Rich Roll?

  Okay, Simon, Simon Hill. So Simon's basic thesis is that when we consider all facets of health, human health, of course, but also planetary health, soil health, ecosystem health, animal welfare, that the argument for a diet that is as plant-exclusive as possible becomes irrefutable. Today, we hit all the hot topics: tribal diet wars, what the science says, what it doesn't, the environmental implications of our food choices, the truth about saturated fat, cholesterol, and seed oils, and of course, the key things you can

• 5:06Rich Roll?

  and should be doing now to perform at your peak, sidestep disease, promote longevity, and live both optimally and consciously. For so many reasons, Simon is the health and nutrition resource we need right now, and this one is packed with crucial, perhaps even life-saving, information, including links provided by Simon to all studies that he references throughout the conversation, which you can find in the show notes on the episode page at ritual.com. So, break out pen and paper and enjoy my conversation with Simon Hill. Mate, how long have we talked about doing this?

• 5:47Simon Hill?

  It's been a long time.

• 5:48Rich Roll?

  It has been a long time, years, in fact.

• 5:52Simon Hill?

  I know.

• 5:53Rich Roll?

  I was in Australia, I was tempted to do it with you then. I've been on your show a bunch of times. We've been friends for a couple of years at this point. I think I reached out to you to do this earlier, but you kind of wanted to sit on it until your book was coming out. So we waited. Here we are, you're in Los Angeles. Good to see you, my friend.

• 6:12Simon Hill?

  Thank you. Likewise. It's bloody awesome to be here, let me tell you that. It's been a long time coming, you're right. But I think it's nice timing with the book coming out.

• 6:23Rich Roll?

  Yeah, absolutely, man. And I'm excited to get into the book and everything like that. But just, you know, sort of a prefatory way of contextualizing this, the thing that I, you know, besides our friendship, the thing that I really appreciate about you the most is your very kind of grounded, rational, non-absolutist approach to nutrition. Everything that you talk about and advocate is... Objective, it's evidence-based, you're not driven by ideology, you're calm in your delivery, you have experience and education in nutrition, you're non-hyperbolic, and

• 7:03Rich Roll?

  your analysis of nutrition science is always deeply rooted in the studies, and your advocacy is oriented around actionable, doable changes that people can make, and you deliver all of this in a non-judgmental and very even-keeled approach, which I think is something that we not only need right now, but I think we're thirsting for in a kind of social media landscape, at least, that tilts towards extremism and hyperbolic narratives.

• 7:42Simon Hill?

  Yeah, well, that means a lot to me because, you know, I think I pride myself on trying to communicate the science as objectively as possible. And, you know, I'm a big believer in science and how science can help us better understand the world, and better navigate it, and improve our lives. But you're right, I think a lot of the nuanced conversation has been lost, and some of that is a result of social media and the algorithms that are at play, and the absolute message is often, you know, favored from an engagement

• 8:24Simon Hill?

  point of view. It will reinforce one's identity, and at the same time, perhaps, challenge and trigger the other side's identity, which is the ultimate result if you're looking to create engagement and excitement. So, you know, I've, ever since I was a little kid, I have had a deep appreciation for science, and...

• 8:52Simon Hill?

  Being able to use it as a tool to help reduce the amount of uncertainty. And that's what science is.

• 9:01Rich Roll?

  Yeah.

• 9:01Simon Hill?

  It's it's using a method to test our intuition, our hypotheses and to reduce that uncertainty so we can make decisions with more confidence.

• 9:16Rich Roll?

  Hmm.

• 9:17Simon Hill?

  Uh, and so my approach with nutrition science has always been to let the science do the talking and be led by the data, be open to changing your mind. And, you know, a lot of that I've I've really learnt from from my dad.

• 9:36Rich Roll?

  Hmm. Yeah, your dad was a scientist, a medical doctor. Yeah. And you have this kind of evolution story of how you got into nutrition science that that really begins with a health crisis that was faced by your dad.

• 9:50Simon Hill?

  Hmm. Yeah, I, when I was maybe three or four years old, that's sort of as far back as my memory goes, maybe five. Uh, as early as I can recall, you know, I would be surrounded by scientific papers. My dad would print these things out. And they would fill up the coffee table. And, you know, if I, if he picked me up from school, I'd have to lift them up off the car seat just to get into the car and they'd always be highlighted. And I couldn't make much sense of them, but I could see how important science was to my dad and the work that he was doing. He he got his PhD in Texas.

• 10:31Simon Hill?

  So we we moved as a family to Texas where he did his PhD in physiology. And, you know, has gone on since then to to have thirty or forty years of of academic research as a professor and, you know, publica- publishing in, you know, circulation and metabolism, leading journals and a very well-respected professor uh, in in his field of physiology, which is looking, you know, right. Under a microscope at the micro level mechanisms, deep science, you know, much deeper than what I do. I I tend to zoom out and think about what's what's the big picture? What does this mean to you and I? How can we make better decisions and be healthier?

• 11:16Simon Hill?

  And how can we consider the world around us?

• 11:20Simon Hill?

  But, you know, his his research, you know, equally as important, uh, understanding the mechanisms that are at play has been dedicated to to looking at how our arteries function and and dysfunction. And uh, what happens when you develop type two diabetes and cardiovascular disease? And um, this is somewhat ironic because you're right, I did experience for the first time what loss of health looks like. And on on weekends, my dad and my brother, you've met my brother. A couple of years ago here in L A, James. And uh, he's actually the one that introduced me to your show originally.

• 12:07Simon Hill?

  On weekends, when we had moved back to Australia, so when I was about 10 years old and my dad had finished his P H D in and was working as an assistant professor in America. We moved back to Australia and on weekends we would go and explore an area called the Yarra Valley. And it's it's a beautiful wine district in Victoria, you know, rolling hills, uh, incredible scenery. And we would go and visit little wineries. My dad always liked to choose the small ones. And, you know, if you if you went to these more boutique wineries, and this wasn't about the the alcohol.

• 12:51Simon Hill?

  It was about the experience and you you could speak to the winemaker usually. And, you know, you could see their passion they had for what they were doing. And so we we would have a lot of fun together, exploring these areas. And on this one particular day, and it was just my dad and I, we we had a fantastic day out together and, uh, you know.

• 13:17Simon Hill?

  My dad had an MGB convertible. I can remember these days vividly.

• 13:22Rich Roll?

  My dad had an MG Midget.

• 13:24Simon Hill?

  Yeah.

• 13:24Rich Roll?

  So I know, I know the vibe.

• 13:26Simon Hill?

  You know, great, great cars and the, the roof would come down and we would play classics like U2 and Rolling Stones and Cat Stevens and, you know, all that sort of stuff. And I think, you know, a lot of people listening perhaps can relate to that, perhaps with experiences with, you know, their parents or uncle or someone in their life, those days you look back on, you know, 20, 30 years ago, uh, and with, with very sort of fond memories. These were those days for me. And on this one day in particular, as we're driving home, it's dusk. I could see that my dad

• 14:07Simon Hill?

  was uncomfortable and he was slightly grimacing and he was also rubbing his chest. And I asked him if everything was okay and he said he was feeling some chest pain, but downplayed it and we continued to go home and, and cook dinner. And I, I remember checking in again and he said that everything was fine. So we had dinner and thinking nothing of it, I went off to bed. And a short while afterwards, I woke to some noise in the kitchen and I thought, well, thinking about what had happened, I, I better go and check if he's okay. And when I

• 14:52Simon Hill?

  went out, I could see he was making his way to the phone. He had, he had the phone in his hand by that stage and, uh, he was on his knees. He, at this stage, this was Rich, the first time that I've ever seen my dad.

• 15:10Simon Hill?

  With so much fear in his eyes. It was a point now that he he could no longer deny what was happening. And he was pale, he was out of breath. And it was very obvious that he was struggling. Mm hmm. And so I actually spoke with the lady on the other end of the line. He'd called triple zero, which is like calling nine one one here. And I I was explaining what was happening. And all of this was happening super quickly. And, you know, I was fifteen at the time. My dad was forty one. Hmm. This was Young. Out of nowhere.

• 15:53Simon Hill?

  Um, you know, he he was not reliant on the healthcare system. He had no medical diagnosis. He was not taking any medications. He was living the standard Australian lifestyle. And if you looked at my dad at that stage, you would not look at him and say he is particularly unhealthy. You know, he he was in, you know, decent shape and would exercise. And, you know, for all intents and purposes, was just representative of a young Australian dad. Right, and studying vascular physiology at the time. Right, so, you know, many years later and and now a better understanding what happened

• 16:36Simon Hill?

  and and the disease at play, which I'll go into. Uh, you know, it's become clear to me that my dad knew exactly what was happening at the time. And I think this denial is quite common, particularly in males that are experiencing poor health. Yeah. And perhaps if you deny what you're feeling, it will go away. Right. Uh, I'm not sure it works like that. Yeah, I have some familiarity with that. Yeah, uh, you know, so the the lady on the other end of the line, after me explaining what was happening, said, we need to send a helicopter.

• 17:15Simon Hill?

  And so where we were at that point in time, my dad had a place in King Lake. So my parents were separated when we moved back, they got divorced.

• 17:27Simon Hill?

  When we moved back to Australia and my mum and my brother and I, we were actually living in Melbourne. And then we would spend weekends with dad. So they said, we need to send a helicopter. King Lake is quite remote. It was like this mud brick house in the middle of nowhere. My dad's always loved being out in the middle of nowhere.

• 17:48Simon Hill?

  And then anyway, it was a long way from the nearest hospital. So they did, they sent a helicopter and it came so quickly. And they rushed in and scooped him up, put him onto a stretcher and put him on oxygen and were checking his vital signs. And before I knew it, he was in the helicopter and it was flying off and I couldn't fit in the helicopter. So they said to me, I could follow in a, in a car, in an ambulance to the hospital. And by that time, I, I called my mother and my brother and said, you probably should come to the hospital, this is what's happening. I don't know what the outcome is here.

• 18:31Simon Hill?

  We really don't know the specifics, but dad's not in a good way. And, you know, that car ride to the hospital, it, it felt like it took forever. And we got to the hospital and we waited and waited. And then, you know, the doctor came out and said to us, we've saved your father's life. He's had a severe heart attack, which of course, that was, you know, the fact they saved his life was what we were most concerned about then and there.

• 19:03Simon Hill?

  But we were very shocked that at forty one, this had come out of nowhere. And the next day, there was a family meeting, you know, as there often is, it's a bit of a debrief, you know, what's happened, what's the prognosis, et cetera. And so we met with the cardiologist and he had taken my dad's history and it was quite clear that cardiovascular disease did, does run in my family. And my grandfather had had a heart attack at about age sixty one, I believe. My grandmother, so my dad's, that was my dad's dad, my dad's

• 19:43Simon Hill?

  mum, my grandmother, she had vascular dementia. And so the cardiologist said to my brother and I, my brother was eighteen, I was fifteen, he said that, you know, cardiovascular disease runs in families, clearly it's running in yours, and this will be something that you need to be screened for as you get older. And looking back on that today, that, that is great advice. But the conversation ended there.

• 20:15Rich Roll?

  Mm hmm.

• 20:16Simon Hill?

  And, you know,

• 20:18Rich Roll?

  Yeah, it's, it's, it's, you know, it lacks any sense of agency. This is a predestined thing. This is genetically, you know, motivated and you're going to have to contend with it at some point. But, and that, that's very much of that time as well, right? Like, we know a lot more now about how we can intervene and make these lifestyle choices. But, you know, I was told the same thing. My grandfather died early. Like, I know that whole drill. And, and what it leaves you with, and you tell me how you felt, was this, you know, sense that there really isn't much you can do about it.

• 20:52Simon Hill?

  Yeah, you've been dealt a bad card.

• 20:54Rich Roll?

  Mm hmm.

• 20:55Simon Hill?

  So, I mean, that is how I felt and my brother felt for many years, was that, you know,

• 21:04Simon Hill?

  What's to say we're not going to follow in my dad's footsteps? You know, he was, he was living a typical Australian lifestyle. He wasn't from the outside unhealthy and this has happened to him. So how, why will it be any different for us?

• 21:17Rich Roll?

  Right.

• 21:18Simon Hill?

  You know, if you do the same thing as everyone around you, how can you expect different results?

• 21:21Rich Roll?

  Right.

• 21:23Simon Hill?

  So it's disempowering when, when you get that news and you, you put your health down to purely to genetics.

• 21:33Rich Roll?

  Yeah.

• 21:35Simon Hill?

  And, you know, it was, it was many years later that I would come to learn that, you know, while genetics do create predispositions and can increase your likelihood of developing a certain disease, your lifestyle and the way that you're, you're navigating your life has a lot more say.

• 21:57Rich Roll?

  Mm hmm.

• 21:58Simon Hill?

  And, you know, there are a bunch of, of studies looking at identical twins. For example, exact same genes, different environments growing up, nature versus nurture. What happens? And these studies have been able to tease out what is the impact of genetics versus lifestyle? And broadly speaking, and of course this can, this is different depending on the type of, of genes that someone has. But broadly speaking, if we're thinking about, you know, these big chronic diseases like cardiovascular disease, type two diabetes, fatty liver disease, even Alzheimer's dementia. Broadly speaking, your genes are, are controlling about 20% of your health fate.

• 22:43Simon Hill?

  And that means that your, your environment and your lifestyle is controlling 80%. You know, it's four times more powerful. And so, uh, of course, when you come across that information, then, you know, the game changes. The narrative flips from being disempowered to being incredibly empowered.

• 23:04Rich Roll?

  Yeah. So it was your brother, correct me if I'm wrong, who was the first instigator in terms of getting you interested in nutrition?

• 23:12Simon Hill?

  You've done your research.

• 23:13Rich Roll?

  A little bit. I know you too, so it's not like.

• 23:19Simon Hill?

  Uh, I didn't expect any less. Uh, yeah. So, you know, finishing, uh, when I finished high school, I, I actually wanted to become a doctor.

• 23:33Rich Roll?

  Mm hmm.

• 23:34Simon Hill?

  And I got really, really strong grades at school, but not quite strong enough to get into medicine in Melbourne.

• 23:41Rich Roll?

  Hmm.

• 23:42Simon Hill?

  And so I was accepted to do medicine, but in Tasmania.

• 23:45Rich Roll?

  Hmm.

• 23:46Simon Hill?

  And I, I wasn't quite prepared to, to, to make the, the move down to Tasmania and give up my friendships and give up playing football. And, uh, so I made the decision to stick around and, uh, I did physiotherapy instead in Melbourne. And, uh, the reason I, I tell you this is because I was very much indoctrinated and I was surrounded by this fitness culture. I was working in football club environments. And this is, these are environments where animal protein is king.

• 24:21Rich Roll?

  Yeah.

• 24:22Simon Hill?

  And so there was a, a Christmas where my brother was coming up to stay with me and with his fiance at the time, Lauren, who's now his wife. And he called me up and he said, you know, we've, we've been reading and listening uh, to a few things, probably your podcast and, uh, and probably some of Dan Buettner's work, I believe. And, uh, you know, he, he had come across some information to suggest that there were, there were populations that were not experiencing the same levels, the same degree of cardiovascular disease that our society's experienced.

• 25:03Simon Hill?

  And of course, thinking back to our, our dad's history and grandfather's history, that was meaningful information from a brother I'd come across and enough for, for him to want to explore. And he's, uh, you know, from a, a business background. So it was, it was not something that was inspiring him to get deep into the science or the weeds with. Uh, he just, he felt that the information was, uh, of high enough quality to act on. And he called me to say, Lauren and I have changed the way we're eating a bit. And it was a bit of a heads up. You know, they were coming to stay with me and and I was going to do some grocery shopping, of course, and and take them out for dinner.

• 25:45Simon Hill?

  And and he said, we're we're no longer eating red meat and chicken. We've we've adopted a pescatarian diet. I think this might have been like my introduction to dietary labels. Before then, I hadn't given a whole lot of thought to all the different dietary labels that exist, or the dietary wars. I was just, you know, doing what what I knew. And, you know, I said to him, well, that's that's cool. Uh, you know, I eat fish and we can make that work. And I'm sure we can find restaurants that will cater for that. And about that was a few months before him coming up.

• 26:25Simon Hill?

  And then about a week before he came up, he called me up again and he said, yeah, we've uh, we've changed our diet a little more.

• 26:36Simon Hill?

  The volume's getting turned up. Yeah, and and I thought, okay. I thought maybe he'd he'd reverted. And he said, well, we've we've decided to remove the fish. And I was thinking, what the fuck is left? You know? How long ago was this? This is two thousand and fourteen fifteen. Uh, not that long ago. Twenty fourteen fifteen. Uh, and so I said to him, I said, look, well, I'm definitely going to need some help with regards to knowing what to buy and and certainly with restaurants. You know, I had no business in choosing the restaurants that would be catering for for vegan meals.

• 27:18Simon Hill?

  You know, to be honest, I had never really considered a a diet without animal products. And he came up and both he and Lauren are uh, are are great cooks and particularly Lauren. And so they did a lot of cooking and we went out to some restaurants and.

• 27:43Simon Hill?

  The the feeling that I was left with at the end of those two weeks was, you know, not any pressure from them. They weren't asking me to consider how I was eating. We just had a great two weeks together and the food was delicious. And so the feeling that I was left with was, well, if my brother's right, and there is some information out there that suggests you can change the way you're eating and reduce your risk of cardiovascular disease, and I know that I don't have to sacrifice on on flavor and joy and and the experience, then this is something that I should be looking into.

• 28:25Rich Roll?

  Right. But for those that aren't watching on YouTube and are just listening, what you might not know is that, you know, Simon is a is a physical specimen. Like, you're a buffed, big, strong guy, and you're working with Australian Rules football guys at the time. Like, your focus is on performance and strength and agility and all of these things, right? So how does that information mesh with everything that you knew up to that point and were interested in? Because, yes, oh, I feel good and this tastes good, but how is this going to fuel me and, you know, keep me in the physical condition to which I'm accustomed?

• 29:07Simon Hill?

  So I I had that fear completely. I think for the first step for me was was first looking at the information and science around chronic disease. And then, when I had unearthed information there and it became clear to me that there was a way to eat to reduce your risk of chronic disease, the next step was, am I going to have to sacrifice the physical performance, athletic pursuits? Am I going to be able to maintain improved strength, et cetera? So the, you know, the first step, Rich, for me, from after that, was, you know, I was trained in physiotherapy initially. You'll remember, at this time,

• 29:52Simon Hill?

  I actually hadn't done my Masters in Nutrition Science. This has been that that's been done in the last seven years. So when my brother came and stayed with me and inspired me to think about this, I had no formal training in nutrition. I had done an undergraduate degree in physiotherapy, which is a four-year sort of bachelor in science. So you cover a lot of physiology and anatomy. And I had a, I did an honors year where I wrote my own thesis, performed a review, conducted my own study and wrote it up. So I understood how to look at research and analyze it, albeit from a, from a different lens, a different area of science. So the first step for me was to try and look, get

• 30:37Simon Hill?

  into the literature and see if what my brother was telling me was true or not. And I, I, you know, I quite often say, I wanted to prove him wrong. I, I was healthy. I wasn't having any health issues. I was strong. I was fit. Everything about my diet seemed to be working for me, not against me. And as I was getting into the research, initially, what I realized was how many polarizing views there are and how confusing it is and tribal. And one moment I thought I understood something, then I would see the exact opposite.

• 31:21Rich Roll?

  Right.

• 31:22Simon Hill?

  And that's what inspired me to go and do the masters in nutrition science because I realized even though I had training at an undergraduate level in science, I was not equipped with the skills to, to make full sense of it and to really decode it. And so it was back to university and to, to really focus in on, on the research-based side of things and, and then get right down into the weeds of the nutrition science to, to try and understand exactly what an optimal diet looks like.

• 32:00Rich Roll?

  Right. So you get your masters in nutrition science. There's a whole like sort of backstory or backdrop here, this entrepreneurial journey that you've been on. That's almost its own podcast. We can maybe revisit that in a little bit. But you emerge from that experience. You become steeped in the science. You have this kind of urgent call to advocacy that leads you to. Create plantproof.com and the Plant Proof Podcast and, you know, the latest iteration now being this new book, The Proof is in the Plants. But walk me through

• 32:38Rich Roll?

  how you arrived at a certain kind of global thesis around nutrition and perhaps state that case.

• 32:48Simon Hill?

  So I guess the thesis, to start here with the thesis, and then I can go into how I came to that and how I look at science in general. The thesis is that there is, there is a set of characteristics or a theme that define a, an optimal diet. And rather than one particular dietary brand being absolutely proven by science as the most optimal. And this theme is that, you know, diets that are low in saturated fat, that provide good amounts of unsaturated fat, that are rich in fiber, that have a good amount of plant

• 33:29Simon Hill?

  protein, and are low in ultra-processed foods, time and time again, lead to good health outcomes. You know, these are the people that are experiencing less cardiovascular disease, less, less likelihood of having a heart attack or a stroke, less risk of developing type 2 diabetes, less risk of fatty liver disease, less risk of various cancers, and less risk of neurodegenerative diseases. And the cool thing, I guess, about that theme is that there are many variations of that. You know, that could be a really thoughtfully constructed Mediterranean diet, Mediterranean diet as described by Ansel Keys, who was

• 34:14Simon Hill?

  a very prominent scientist in the mid 1900s. He described that as a largely vegetarian diet. You know, it does include some animal products, but they're not as emphasized as a standard Western diet today.

• 34:27Simon Hill?

  It could be a really well-done pescatarian diet. It could be a really well-done vegetarian diet. It could be a completely plant-exclusive, whole-food, plant-based diet. And so it means that there are lots of ways to eat your way to good health. And that's a less absolute message and perhaps not as sexy.

• 34:51Rich Roll?

  Yeah, that makes it difficult. You can't come up with a label for this or some kind of contrite, specific, drilled-down term that allows it to trend on Twitter and create a simplified idea that can get lodged in someone's brain. But that's science.

• 35:12Simon Hill?

  That's science. And the way I like to describe this to people is that any of those diets, if you compare them to a standard diet, and there are a bunch of studies that have done those, you'll see significant risk reductions for various diseases. But if you were to run, let's say, a randomized controlled trial from birth and just include those dietary patterns that I just mentioned, which are all very thoughtfully constructed diets, and you were to follow those people across their lifespan, you're unlikely to see any difference in outcomes because all of those diets are so vastly, so significantly different

• 35:57Simon Hill?

  to the standard Western diet, which is the diet that is provoking disease the most. And so how do I look at science and come to that conclusion? A few different principles guide the work, I guess, that I do. And when you understand these principles, it also makes social media and the headlines a little frustrating.

• 36:28Simon Hill?

  But I guess firstly, not all science is equal.

• 36:32Rich Roll?

  Right, so we could talk about the hierarchy of science. We hear terms like randomized controlled trials, population studies, epidemiological studies, all of that. And perhaps we have some familiarity with what those mean. But walk us through that hierarchy and how we parse fact from fiction when it comes to evaluating the multitude of studies that are out there, among which you can always find, you can find a study or cherry pick this or that that's going to affirm your thesis.

• 37:05Simon Hill?

  So yeah, the evidence hierarchy allows us to to kind of add weight to certain evidence based on how reliable and valid it is. And at the very bottom, which is the sort of least reliable and least valid evidence, is expert opinion. That's if I just say something without a citation, you know, someone, a professor or a doctor just says something, that's considered very weak evidence. Just above that is laboratory studies. These are in vitro studies, looking at cells under a microscope, or animal studies. And you know,

• 37:49Simon Hill?

  this, it's not to say that this science is not important. It can be an important part of piecing together the puzzle. But it's hypothesis generating.

• 38:00Rich Roll?

  Right. The idea that a certain metabolic pathway in a mouse that you could extrapolate to how that applies to human health is tenuous at best.

• 38:09Simon Hill?

  Yeah, and we see, you know, time and time again, lectins or soy, and a lot of, a lot of people generating fear about these. And they are, they are arriving at that conclusion based on this sort of in vitro animal based study, and overlooking the human health outcome data, which, which really is a more valid source of information for public health recommendations. It's interesting to see what happens in a cell or in an animal, but we also then have to zoom out and see what, what happens in a human. And and also you can fall into some some traps with with research in in an animal

• 38:52Simon Hill?

  or or in vitro where the the exposure level is very important. You can, for example, you could, if you're looking at phytoestrogens in soy, for example, you could look in an animal model and show estrogenic effects. And and then perhaps that could get you worried about the development of hormone-dependent cancers like prostate and breast cancer. But what a lot of those what a lot of those studies have looked at, if you were to look at the exposure level on a per kilo grams of of those phytoestrogens per kilogram of

• 39:37Simon Hill?

  body mass or pound of body mass, what you would see is that the the exposure level in that that rat is magnitudes higher than the exposure level that any human would ever be exposed to through eating soy or tempeh, et cetera. So not only is physiology different at the animal level between an animal and a human, but also sometimes exposure can be significantly different. So that's, I guess, the the sort of level above expert opinion.

• 40:16Simon Hill?

  And, you know, I think something else that is probably useful here is, you know, Fleming discovered penicillin. And I think that was back in 1936 or something. Yeah, mid 30s. Yeah. And he he discovered that through, started in a Petri dish that he'd left out. And he saw that this mold was destroying the bacterial cells. And then by studying the mold, he was able to isolate penicillin. And then he was able to use penicillin effectively in rats as as an antibiotic and then was able to do it again in humans. And that kind of progression.

• 41:01Simon Hill?

  That that progression is actually very rare. You might have a hundred, fifty, a hundred thousand discoveries in a rat that don't play out in a human for every one that does. So, you know, we hear of these success stories like Fleming and penicillin and we think, well, oh, you know, the animal model is is a great model and sound. But what we don't hear of is how often it fails. So I think it's just an important reminder that it is a hypothesis generating level of science and, you know, really, we shouldn't be making public health recommendations

• 41:41Simon Hill?

  from that level of science alone unless there is zero human outcome data and you want to take a sort of precautionary stance. Right. So then the rung above that is observational science, epidemiology. And there are a bunch of different types of observational study designs. But the the key point here is you're looking at humans that live in a population and you're observing the way they live. In the case of nutrition, you're looking at what they eat or don't eat. And you're looking at specific health outcomes. And you're trying to see if you can find any sort of tight associations.

• 42:26Simon Hill?

  You know, these people that are eating more of this end up having a higher risk of this. For example, people that are eating more ultra-processed meats have around eighteen percent higher risk of colorectal cancer per fifty grams consumed per day. And it's not a perfect science, but no science is. Sure. And I think often observational science gets slammed by by certain folks out there. And and one of the common sort of criticisms is that there is a healthy user effect. And and that is that, you know, if you're looking at at that populations of people

• 43:10Simon Hill?

  who are eating more fruits and vegetables and and you're looking at health outcomes, be it cancer or cardiovascular disease. Perhaps it's not the fact that they're eating fruits and vegetables, but that that's a sign that they live a healthy life.

• 43:26Rich Roll?

  Sure, there's all these confounding variables. And the Achilles heel being that when you're in this observational modality, you can't control for any of those variables. People are just living their lives. So there's also the risk of rife misreporting as well. Because it's based on people reporting what they're eating and how they're living on some level, right? So, you know, are people actually writing down what they're really doing? Or are they writing down what they think you want to hear? There's room for all kinds of error. But at the same time, if you're taking massive populations of people, you can extrapolate from that some general trends. And there is some level of reliability with what you're observing.

• 44:09Rich Roll?

  It's just limited in terms of what you can extrapolate from that.

• 44:12Simon Hill?

  Yeah, you can't, you can't create a sort of cause and effect conclusion. You can't say that, that variable A is causing this outcome. So you can only speak to associations. But even, I think something that's really important here is that the researchers are aware of the limitations of this study design. And, and, and so the, you know, the confounding variables, for example, although you might not be able to remove their complete effect, they do through statistics, control for them. So the idea is if you are really well,

• 44:55Simon Hill?

  if you have a really well-defined population, that you are as best as possible, working out how often people drink alcohol, how often they smoke, how often they exercise. And in your analysis, let's say, for example, you want to look at the fibers effect on a certain health outcome. The idea with with controlling for confounding variables is that we're not going to compare people that have significantly different consumption of alcohol. What we're going to do is compare high and low fibre between people who are exposed to the same amount of alcohol.

• 45:38Simon Hill?

  So that's the idea through adjustment is to remove some of the effect of these confounding variables. And so there is a statistical protocol called multivariate analysis, and the researchers use this to the best of their ability. When it comes to the food frequency questionnaires, they do have their limitations, but they also validate them in that population to, if it's a good study, that's what they should be doing. They they have tools to validate that food frequency questionnaire, which means going out and performing a study to make sure that, as you say, you know, what people are reporting is reliable, and there are methods of doing that.

• 46:19Simon Hill?

  So it's it's sort of, you know, they're not just going out and completely shooting in the dark. There are steps and processes within epidemiology to produce good epidemiology. And of course, there can be bad epidemiology as well. And then above that, what's the next tier up? So above that is your randomized controlled trials. These are clinical interventions. And the idea here is that by having a clinical intervention, you can you can remove the effect of other variables other than what you're looking at. So it's very controlled. Perhaps you have two different groups, and the only difference between those two groups is the exposure that you're looking at.

• 47:03Simon Hill?

  Maybe it is, for example, the addition of fibre to a diet, or the addition of a certain vegetable oil. And therefore, you can have a greater degree of confidence that the outcome that you're measuring is a result of the the difference between those two variables. The cause and effect. Yeah.

• 47:25Rich Roll?

  And then above that, we have the, these meta-analyses, right? Like where you take all of these studies that are of a certain ilk and lump them into one pile and kind of compare and contrast all of them to draw even deeper conclusions.

• 47:40Simon Hill?

  Yeah, so the idea is if you pull together 30 randomized controlled trials from around the world that are all looking at the same thing, from different researchers in different labs, and you pull them together and perform an analysis, you're likely to reduce the chance of any bias that could be affecting any individual study. That said, a meta-analysis is also, you know, there are, there are times where a meta-analysis can be performed poorly. It has to define what its inclusion criteria is and therefore what studies it includes.

• 48:22Simon Hill?

  And if you put garbage in, you're going to get garbage out. So a meta-analysis, again, is not bulletproof. You still have to be able to look at it, understand what the inclusion and exclusion criteria was, and then, you know, look at the results in the context of everything else. And that's the key here, is that when, when you're reviewing the science and you're looking at any individual study, you then have to step back out and look at the totality of the evidence. Ideally, what we're looking for is converging lines. You know, the mechanistic studies under the microscope and in the animals are pointing in the same direction as what the epidemiology is pointing in, is pointing in the same direction

• 49:07Simon Hill?

  as what the clinical intervention studies are.

• 49:17Rich Roll?

  Yeah, I think this is all really important. I mean, the reason I wanted to dive into this hierarchy of evidence is simply because I think it's important that people develop some level of evidentiary literacy around this, particularly when people are going online and they're reading stuff on Facebook or Twitter, and somebody's promoting a certain diet or lifestyle and they're using... Study X, Y, or Z as evidentiary proof of this. It's important to understand, well, what kind of study was that? What are the circumstances under which it was conducted, et cetera? And what you see with respect to the tribalism that abounds is a certain group.

• 50:00Rich Roll?

  And this cuts across every dietary tribe. Like, they will throw an epidemiological study under the bus because that's trash. But then they'll cite one that supports their perspective. And there's this kind of war of ideas that goes on where shots are fired across the bow at each other. And for the average consumer, it's like, I'm not reading these studies. I'm not going on NBCI and like trying to figure all this stuff out. And it's really hard to find somebody who's coming from an objective point of view to help people parse all of this out. And I feel like you're a good actor in this space. Somebody who's willing to admit when they're wrong, who's teachable, who's learning as

• 50:45Rich Roll?

  we go, sharing what you're finding along the way, calling out BS when you see it. And that's a real public service.

• 50:54Simon Hill?

  Yeah, there's a lot of false equivalence is how I like to describe it. Where you, you know, on social media, everyone now, if you read the blog or the post on social, first two words, "Studies show." And yeah, it's, you know, how can studies show such contradictory positions? And how can such contradictory positions exist? So it is, it's frustrating. And I can see from someone who's just trying to make sense of things that it's incredibly difficult. And I think many people are left with this idea that science isn't settled.

• 51:37Simon Hill?

  Science doesn't understand what a healthy diet is. Look at all these different opinions that are out there. And then, you know, when you're in that position, it's very easy to kind of just throw your hands up in the air and stick with what you know and what you're comfortable with.

• 51:52Rich Roll?

  Creates a paralysis.

• 51:53Simon Hill?

  Yeah. So. I do think it's important for people to understand this evidence hierarchy.

• 52:02Simon Hill?

  But equally speaking, you know, I think something that I've also sort of grown to learn over time in, in, in trying to communicate this message is not to expect too much from, from the average person trying to make sense of this. And what I mean by that is people are busy. They, you know, they have their own careers, their own jobs, and they're not like me, sitting down and reading nutrition science papers seven, eight hours a day and geeking out on them. And that's cool. They've got their own passions and, and, and interests. And this is, you know, we hear this kind of throwaway line of, of do your own research, or I did my research. Yeah.

• 52:45Simon Hill?

  And, you know, I kind of, I kind of laugh sometimes when I hear that. I mean, really doing your own research, if you think about that, that phrase literally would mean going and getting trained in a bachelor's and then becoming a professor and having a research question and then raising grant money and performing the research. Yeah. And hiring the statisticians, I always, I always fumble that word, and the, the research assistants and performing the research. Or it could be someone who's maybe not performing

• 53:23Simon Hill?

  the research themselves, but is, is trained to, to read it and to get into the study and understand exactly what they're looking at and to look at the exposure that I spoke about before, compared to what, if we're looking at a certain food or nutrient and we're looking at an outcome, what are we comparing it to? Such an important question. That's that's often overlooked, understanding the evidence hierarchy, being able to zoom out and think about the totality of the evidence. All of this stuff, I think it's it's a big ask to ask the average person to to be doing that on the regular, to make sense of things.

• 54:05Simon Hill?

  And and this is where I think the this consensus guideline papers from the American College of Cardiology, or the, you know, American College of Endocrinology, or the American Cancer Society. These guideline papers are, they are those people who are conducting the research themselves, who are trained to read the research, to understand the the totality of the evidence, and then provide recommendations. And so when I see someone say, do your own research, to someone, you know, I I think that it's a little unfair.

• 54:44Simon Hill?

  And I think in many ways, what's more constructive is just to point them to a good resource where there are, you know, very credible, experienced people that have been engaged to do exactly that.

• 54:57Rich Roll?

  Right. Do your own research often means, I found the guy who I like and I resonate with him. So and and I find him to be credible and believable. So I'm on some level, there's a leap of faith and a level of trust that that person is telling me the straight truth.

• 55:14Simon Hill?

  And the, you know, the the less aware you are, I guess, of the way that science works, I think the more affected you can be by confirmation bias. And and so it can be easy to just go and and find the information that reinforces your current views, established views, your identity, and at the same time, turn a blind eye to anything that perhaps challenges that. And so, you know, I think that right now.

• 55:51Simon Hill?

  I empathize with the average person trying to make sense of what on earth to eat.

• 55:58Rich Roll?

  Right.

• 55:59Simon Hill?

  And, you know, people are terribly confused and caught in the middle of all this.

• 56:04Rich Roll?

  So as somebody who has, you know, quote unquote, done the research, like you're a guy who's done the research, you've looked at the totality of evidence, you've extrapolated from that to develop this thesis that you spoke about earlier, which on some level I feel could be said in more simple terms to be a plant predominant diet, perhaps not a plant exclusive diet, although that's great, but a diet that leans in towards mostly plants. Is that fair?

• 56:39Simon Hill?

  That's fair. So a plant predominant to a plant exclusive diet and, you know, why does this work? Well, it's, there's a twofold kind of effect going on here. You're reducing your exposure to certain foods and nutrients that we know when consumed in excess will promote disease. Things like saturated fat, for example, that are the most common source of saturated fats is in animal foods. You're reducing your exposure to certain carcinogenic compounds. You're at the same time reducing your exposure to ultra-processed foods. You

• 57:22Simon Hill?

  know, let's not forget that in this country, 60% of the average person's calories come from ultra-processed foods. And in Australia, it's nearly 50% and similar in the UK and in Canada. And we know it's, you know, we know from clinical intervention studies, and we could go into that if you want to explore it, that these ultra-processed foods are hyperpalatable. They're, they make it super easy to overconsume calories. You know, they, they promote hedonic hunger. You know, we're, we're consuming calories in the absence of a physiological requirement. And they're designed by food scientists to do that, to

• 58:07Simon Hill?

  hit the bliss point. And they've done a good job. Um, if you look at the, the consumption levels. Um, so we, we're reducing our exposure to certain uh, parts of a diet that are promoting poor health. And then at the same time, we're increasing our exposure to fibre, right? And you know, fibre is probably the most overlooked nutrient. If there was one thing that I was going to say to people uh, to focus on that would just straighten up their diet and would reduce their risk of so many of these diseases, help them live healthier for longer. It would be to get more fibre into their diet.

• 58:50Rich Roll?

  Mm hmm.

• 58:50Simon Hill?

  And I know you've had our mutual friend, Dr. B.

• 58:53Rich Roll?

  Yeah, at your, you know, at your insistence earlier, you were the guy who was like, you gotta check this dude out. And then I had him on, of course, he's a rock star.

• 59:00Simon Hill?

  Yeah.

• 59:00Rich Roll?

  He's been on your show many times.

• 59:02Simon Hill?

  Yeah.

• 59:02Rich Roll?

  And wrote the foreword to your book.

• 59:04Simon Hill?

  He wrote the foreword and you know, the microbiome is wild and uh, you know, in, in, in many ways, what's going on in our microbiome and the loss of biodiversity reflects the, the macro world. And it's, it's no coincidence that farming and food production is affecting both. Uh, so you know, the introduction of more fibre to the, to the diet is, is crucial for nourishing the microbiome, for creating a healthy balance of the 38 trillion microbes that, that call your large intestine their home. Uh, and when you're, when you are nourishing them and feeding them, they reward you.

• 59:48Simon Hill?

  And so that's, that's obviously an extremely important benefit of increasing these plant foods in the diet. Uh, you're also in, increasing the amount of plant protein in your diet. And we see very, very consistently in large observational studies that look at substitution analyses. What happens when you reduce animal protein in someone's diet and increase plant protein? And we see dramatic reductions in the risk of all of these chronic diseases. We see reductions in total mortality, the risk of premature death. So that's a, a huge benefit and.

• 1:00:28Simon Hill?

  Perhaps perhaps one of the most important benefits is the exposure to all of these phytochemicals. And there are five, 10, 20,000 plus phytochemicals. You know, we haven't even yet identified all of them. And you've probably heard a lot about polyphenols. And people probably immediately think of risperatrol in in red wine. Or chlorogenic acids in coffee, or curcumin in turmeric, or catechins in green tea. These polyphenol compounds, while not essential nutrients, right? And and when I say not essential nutrients, they're not essential for your survival.

• 1:01:12Simon Hill?

  But they are essential for promoting optimal health. And we know just through work in the last 10 years that most of the polyphenols you eat actually pass through your small intestine. They land in your large intestine. And it's the microbiome, it's the bacteria that that metabolize them. And produce thousands of metabolites that have downstream effects through the body that are driving down inflammation, both systemically, also in the central nervous system. And so as we're making these changes to our diet and eating in this more plant predominant

• 1:01:53Simon Hill?

  pattern, this this way of eating that the Blue Zones eat, Okinawans in Japan,

• 1:02:00Simon Hill?

  the Sardinians, the the folks in Loma Linda, who on average are living around 10 years longer than the standard American. We are producing the risk of these diseases through a range of risk factors that we're modifying. That's the key part here. By driving down cholesterol, by driving down blood pressure, by improving our insulin resistance, you know, all of all of this stuff, along with an anti-inflammatory diet that's that is helping promote a more robust immune system is creating a healthier body.

• 1:02:41Rich Roll?

  So it's multi-factor in the sense that moving towards a more plant predominant diet, you're crowding out space for some of those foods that are contributing to the ailments and the chronic lifestyle diseases. But on top of that, by increasing the diversity of what that plant predominant diet looks like, you're enhancing health in no small part due to the fact that you're feeding your microbiome in a manner in which has all of these extra downstream impacts on health enhancement.

• 1:03:17Simon Hill?

  Yeah, let's perhaps zoom in on the microbiome for a moment here. And not to repeat what you've done with Dr. B, but perhaps we can build on that. You know, the human, the human body is made up of around 23,000 human genes, right? We have, there are around 100 times that many genes in our microbes. So we are genetically more microbe than we are human. And I think there's been some revision on the, on the maths around how many human cells are there to microbe cells.

• 1:03:56Rich Roll?

  Right, yeah, there's been, there has been some changes.

• 1:04:00Simon Hill?

  There's been some changes and used to, used to be 10 to one. It was thought that it was 10 microbial cells to one human cell. And that's been revised to around 1.3 microbial cells to one human cell.

• 1:04:15Rich Roll?

  It's a big change.

• 1:04:16Simon Hill?

  It's a big change. But it still speaks to the fact that, you know, we are, from a cell point of view, we still have more microbial cells than we do have human cells. I mentioned before, there are around 38 trillion microbes in our gastrointestinal system. That is more stars than there are, that is more than the number of stars in the, in the Milky Way. You know, it's, it's, it's wild.

• 1:04:44Rich Roll?

  It's hard to wrap your head around that number.

• 1:04:45Simon Hill?

  Right. There's, there, there is a whole lot going in there that we have underappreciated for, for a long time. The, these microbes.

• 1:04:57Simon Hill?

  They rely on us and we rely on them. It's a symbiotic relationship. And you mentioned diversity. And the reason why diversity of plants in the diet is important is that these, we have about 500 to 1,000 different species within our, within our gut of bacteria. And a more diverse microbiome is associated with better health. We see healthy people have a more diverse microbiome.

• 1:05:32Rich Roll?

  Increasing the number of species of those microbes.

• 1:05:35Simon Hill?

  Yes, so you, most people will have a sort of predefined number of species between 500 to 1,000. And that is usually defined in the first three years of life, right? So increasing diversity is really working with what you already have. But it's increasing the prevalence of the healthy bacteria, the numbers of them, and suppressing, reducing the numbers of the pathogenic bacteria. I think, you know, perhaps a good analogy of this is thinking about society. When there's equal representation of people from different cultures, we have a better functioning society.

• 1:06:15Simon Hill?

  You know, it's, we, we're each, each of these people from diverse backgrounds are bringing different skills to the table. And same thing in society, you know, there are, of course, a minority of people who get up to no good.

• 1:06:31Rich Roll?

  The pathogenic citizens.

• 1:06:33Simon Hill?

  The pathogenics. And, and, you know, we want to keep them at bay, right? And that's the same thing with the microbiome. And so when you have better representation, essentially, if, if you think about a football team as well, you could think about, on any given day, if, if a couple of players aren't performing their best, some of the other players can pick up the slack and you can still win the game. That's, that's what it means. When you have a more diverse microbiome, more robust, you're more likely to be winning and producing these compounds that are protecting your gut lining. And I'll go into that.

• 1:07:12Simon Hill?

  These different species, essentially like you and I, have different food preferences, slightly different taste buds. And, and so the prebiotics and the, the prebiotic fiber and the polyphenols and the resistant starch in certain foods will help promote the growth of certain species, but then other foods will help promote the growth of different species. And so when you have a diverse range of plants in your diet, you're keeping more of these guys happier.

• 1:07:45Rich Roll?

  Mm hmm.

• 1:07:46Simon Hill?

  And as you feed them, they're, they're producing metabolites. So they, they ferment these food products that pass through undigested into the large intestine. And as they're fermenting them, they are producing these metabolites. There are thousands of these, but probably the most studied and spoken about are short chain fatty acids. And of the short chain fatty acids, butyrate probably gets most of the attention and kind of rightly so. Butyrate helps to keep the mucosal layer of, of the gut intact, healthy, along with

• 1:08:26Simon Hill?

  the endothelial cells, which sit, you know, right between, just a very thin layer of cells sit between all the microbes, the 38 trillion microbes, and then 70% of your immune system.

• 1:08:41Rich Roll?

  Which is important because we're seeing this rise in the incidence of, of conditions like ulcerative colitis, et cetera, all of these gut digestion issues, which really relate to gut lining permeability.

• 1:08:55Simon Hill?

  Yeah, I'm, if you look at the surge in autoimmune conditions and, you know, allergies.

• 1:09:06Simon Hill?

  They've they've increased far too rapidly for that to be, you know, down to human genetics. Human genetics take a lot longer than that to change. You know, we're talking hundreds of thousands, millions of years usually. So, you know, something else has changed. And when we look at the the microbiome, it's clear that people who are experiencing these types of autoimmune conditions, they tend to have dysbiosis. Now, I think it would be far fetched to to say that a causal relationship has been established for some of these. A lot of this is epidemiology,

• 1:09:48Simon Hill?

  and it's an association. But there are mechanisms that do make sense. And so the idea is that if you have dysbiosis, and you have less of these short chain fatty acids being produced.

• 1:10:04Rich Roll?

  And just to be clear, dysbiosis being a dysregulation of your gut health in general.

• 1:10:10Simon Hill?

  Yeah, so you've lost that diversity, and you get a relative reduction in the healthful microbes, and you get an increase in the pathogenic inflammatory microbes. And and when this happens, you get breakdown of that mucosal layer, you get separation of the endothelial cells. So the endothelial cells are held together by tight junctions, and butyrate that short chain fatty acid that I mentioned. One of the functions that that it has in the gut is to help keep those tight junctions in good health. And so as you get this more inflammatory

• 1:10:49Simon Hill?

  state in the gut, and this and dysbiosis, you get breakdown of that that layer. This is important because it allows the flow of molecules from the gut into the bloodstream that otherwise that that shouldn't be getting through the gut lining. And these that these are often referred to as bacterial endotoxins, and they they essentially travel into the bloodstream where they rev up the immune system. And when you're driving up inflammation, you're increasing oxidative stress through the body. And oxidative stress leads to DNA damage.

• 1:11:32Simon Hill?

  And then you're starting to accelerate the aging process of tissues.

• 1:11:37Rich Roll?

  So what are the foods that are most butyrate promoting?

• 1:11:41Simon Hill?

  Great question. Have you heard of Professor Christopher Gardner?

• 1:11:46Rich Roll?

  I don't think so.

• 1:11:47Simon Hill?

  So this brings us to a very interesting study that just came out. He's a professor at Stanford. And he was working with the Sonnenbergs. The Sonnenbergs are arguably some of the leading microbiome scientists in the world.

• 1:12:05Rich Roll?

  Yeah, is that a husband and wife pair? Yeah, I've heard of them.

• 1:12:09Simon Hill?

  And they just conducted a really eloquently designed study that took 38 adults, if my memory serves me correct, and randomized them into two groups. And the idea was really to see how fiber affects the microbiome and how fermented foods do. And of course, fermented foods contain probiotics. So the hypothesis was that maybe they improve diversity. And the idea is to test and see if there's a difference between fiber and fermented foods. And this was a 10-week study. Okay?

• 1:12:53Simon Hill?

  The subjects that were told to increase fiber, they increased their fiber from 20 grams to 40. The subjects in the fermented food group, they were told to eat six serves of fermented foods a day. To give you an example, one kombucha was two serves. There was sauerkraut, there was kefir, there was some yogurt. There was about five or six different probiotic-rich fermented foods.

• 1:13:24Simon Hill?

  And the the results of this study were were really interesting because there was some findings that I guess challenged the idea that fiber leads to increased diversity. Right. In the fermented food group, we'll start there, they saw across the board, you know, aggregate increases in in microbial diversity and really impressive increases. So a real um strong finding and a good reason to add more fermented foods to your diet. They also measured markers of inflammation and they measured around 200 odd. So a very

• 1:14:07Simon Hill?

  comprehensive look at inflammatory markers. And they saw that the fermented foods drove down inflammatory proteins, 19 of them specifically. So the introduction of fermented foods was leading to a better immune response and decreasing inflammation in the body. Now, the fiber group, very interesting. There was an individualized response. So if you look at the aggregate, just the average, the the fiber group did not see an increase in microbiome diversity.

• 1:14:48Rich Roll?

  Hmm.

• 1:14:49Simon Hill?

  And that that's an interesting finding and you kind of have to dig into the study to to make sense of of that.

• 1:14:57Rich Roll?

  Right. Why would that be? I mean, that upends prior conclusions around that.

• 1:15:02Simon Hill?

  It does. And when you when you dig into the study, and I've spoken with with Dr. Gardner about this, there were some individuals who handled the increase in fiber really well, and they saw an increase in diversity. And then there were some who didn't and actually saw an increase in inflammation.

• 1:15:27Rich Roll?

  Hmm.

• 1:15:27Simon Hill?

  And they thought this was really interesting because this finding is kind of in spite of of previous understanding. And what they found was when they went back and looked at baseline diversity, the people who who didn't respond so great to increasing fiber, they essentially had very poor diversity to begin with. Okay, and so there are a couple of hypotheses from this study. It's not to write off fibre at all. It's just to say that maybe in certain circumstances, jacking your fibre up from 20 grams to 40 grams overnight is not ideal for some people.

• 1:16:12Simon Hill?

  And perhaps they need tools and strategies to increase their diversity first before they're increasing. And so one of the hypotheses is that if your microbiome is really struggling and you don't have diversity, perhaps you have a long history of using antibiotics, for example, and you've been eating a lot of ultra-processed foods and living a very high-stressed life. We know that stress affects the microbiome as well. Then perhaps it could be a better strategy to introduce fermented foods first, increase some diversity, and then start to add more plant diversity and more fibre into the diet when your gut is in a better position to be able to handle it.

• 1:16:57Rich Roll?

  How long was the study conducted for?

• 1:16:59Simon Hill?

  This was a 10-week study.

• 1:17:02Rich Roll?

  Yeah, it would be interesting to see how that would play out over six months. Perhaps if you just continued to eat fibre at some point, your microbiome locks in on that. But that idea of fermented foods kind of turbocharging things and getting you prepared to be in a position to take advantage of additional fibre in your diet, I think is super interesting.

• 1:17:23Simon Hill?

  Yeah, so I think they're going to go and test that. And they may even look at a probiotic supplement, I believe, as well. But the other thing to consider here, and your point's a great one, because duration of this study is important. And that was one thing they commented on. Perhaps over a longer exposure, the microbiome would have adapted and been better able to handle that increase in fibre. And then you would see proliferation of the bacteria. But the other thing I think that's important here is that it was an overnight jump from 20 to 40 grams. Would it have been different if it was a very slow progression?

• 1:18:05Rich Roll?

  Steeped, yeah.

• 1:18:06Simon Hill?

  So. Look, it, some of that is, is, you know, remains to be seen, but that's the beautiful thing about science. It's, it's constantly evolving. Uh, we know that, you know, from the, the gut microbiome, uh, project, which is led by, uh, a microbiome researcher, Rob Knight, you know, he, he has this huge project and has, has, uh, been creating this database where, uh, people send in their stool, um, samples and he, and, and also, uh, send in information about what they eat. And he's been able to create, uh, a really cool library. And we know from that, that compared to people who are eating 10 or fewer plants per week,

• 1:18:50Simon Hill?

  those that are eating 30 or more have much more diversity in their microbiome. So-

• 1:18:56Rich Roll?

  And that's Dr. B's whole thing. Like, if you're gonna do one thing, increase the diversity of plants on your plate.

• 1:19:03Simon Hill?

  Yeah. So I think that recommendation still stands. Uh, I guess the, the only thing that I would add there is that the process to increasing that diversity, it might look a little different depending on what someone's baseline diversity looks like.

• 1:19:21Rich Roll?

  Sure. And the clickbait title version of that would be, forget about fiber, it's all about fermented foods. Right? A simplified-

• 1:19:29Simon Hill?

  And that happened.

• 1:19:30Rich Roll?

  Yeah, it did happen.

• 1:19:31Simon Hill?

  So that happened and, uh, the Hannah, I can't remember Hannah's surname, but this was, this study was part of her PhD. And I've heard her speak and she kind of had a bit of laugh about that because that's not what the study shows.

• 1:19:48Rich Roll?

  Sure.

• 1:19:49Simon Hill?

  Um, it's, it is a lot more nuanced than that.

• 1:19:52Rich Roll?

  As the world tends to be, Simon, right? Um, that's fascinating. Is there a way, I wanna switch gears in a minute, but to kind of put a pin in this, what's the best way for somebody to figure out what the diversity of their microbiome looks like? Are there tests? Can you like get a stool sample or something like that? How's that work?

• 1:20:11Simon Hill?

  Yeah, there are a couple of different companies that, that are doing this. I'm not sure how reliable they are yet. I'm told that they're getting more and more reliable. So actually, this is a, a, a great question because I think this could be, uh, a key part in helping people work out what, what steps they should take.

• 1:20:33Rich Roll?

  Right. But in the meantime- A good rule of thumb is increase both your fiber and your fermented foods.

• 1:20:41Simon Hill?

  Yep, and you may need to experiment a little bit with that to work with your body and listen to your body. But I think certainly the key finding from that study is that fermented foods are beneficial. And all of us should be eating more kimchi and sauerkraut. And if you eat animal products and you eat dairy, then I would argue that fermented dairy is probably the best of the dairy options. And I do think that some of that technology that you just spoke to, it will become better over time. I think Zoe is one that's out there.

• 1:21:22Simon Hill?

  I'm not sure whether they report so much on diversity in terms of a diversity score for the person. But they do take a stool sample and they do recommend foods. And that's being led by Tim Spector, who is certainly a sort of prominent expert in this space.

• 1:21:42Rich Roll?

  Zoe.

• 1:21:43Simon Hill?

  Zoe.

• 1:21:43Rich Roll?

  That's what it's called, Zoe.

• 1:21:44Simon Hill?

  Yeah.

• 1:21:45Rich Roll?

  Final question on this point. How, what is your sense of the efficacy of store bought kombucha products? You know, you see them advertised with, you know, a certain number, you know, attached to what that culture looks like. But then I think, well, these things are pasteurized on some level. Like, am I really? Like, I could make kombucha at home and we've done that. I'm sure the ones we make at home are going to be more efficacious than what I'm buying at the store. But I've often just thought like, this is probably not doing anything. It's more, it's more of a placebo type situation. But I don't know, have you looked at that or are there studies on this?

• 1:22:29Simon Hill?

  I'm with you. I don't think there are studies on that, but I choose the raw, non-pasteurized kombucha. You can find a few of those. There are some here that I've found in California for that reason. I think if you're pasteurizing them and heating them, then You know, you are

• 1:22:46Rich Roll?

  It defeats the whole entire purpose of the whole thing.

• 1:22:48Simon Hill?

  Yeah, those microbes are likely being killed. Now, in saying that, to add a layer of complexity to this, there is a lot of research now looking at dead microbes. And these are often called postbiotics. And there are some studies showing benefit even through the consumption of dead probiotics. So that's interesting. I don't think we fully understand, you know, is pasteurized kombucha and perhaps the dead cultures that are in there, is that exerting benefit within our garden downstream?

• 1:23:28Simon Hill?

  So I think my advice would be to either try and make your own or to look for one that is a raw, non-pasteurized kombucha.

• 1:23:37Rich Roll?

  Yeah, get your scoby going at home. Yeah. Switching gears, I want to talk about saturated fat. When you articulated your thesis at the beginning of the show, a big piece in that was the reduction of saturated fat. And when we talk about saturated fat, this is a hot button, you know, hotly debated thing, particularly on social media, depending upon your particular dietary tribe of choice. The overwhelming evidence from my perspective of valid objective science is pretty clear that saturated fat, no bueno, contributing to heart disease and other not so good health outcomes.

• 1:24:18Rich Roll?

  So walk us through your sense of the science with respect to dietary saturated fat intake, the impact that it has, and why we should be reducing it.

• 1:24:27Simon Hill?

  How far back should we go?

• 1:24:29Rich Roll?

  I don't know. You got as long as you want.

• 1:24:31Simon Hill?

  There's a great study from 1908.

• 1:24:37Simon Hill?

  That still holds up? Yeah, well, it's interesting because pre 1908 atherosclerosis, a lot of what we're talking about when we're talking about saturated fat is its effect on LDL cholesterol and then the effect that that has on the accumulation of fat in your artery, the development of plaque, you know, in science called atherosclerosis, which then puts you at high risk of having a heart attack or a stroke. And prior to 1908, however, the prevailing sort of idea around cardiovascular disease was that it was just a process of aging and it wasn't necessarily driven through a dietary

• 1:25:21Simon Hill?

  exposure. And there was, this early research goes back to Russia. These Russian scientists were, were in the lab, the first ones really doing work in this space. And, and there was a researcher, last name Ignatowski, and he fed meat and dairy products to a rabbit and was able to, to see that that rabbit developed fatty streaks in its arteries. And that was really the, the very first study that was like, hang on, maybe the development

• 1:26:03Simon Hill?

  of fatty streaks, atherosclerosis that we're seeing in humans is not just aging. However, from that study, the hypothesis was that it was animal protein. And about four or five years later, 1913, Nikolai Nitschkov, quite a famous name in the sort of science world for cardiovascular disease, another Russian. He, he was looking at the, the fatty streaks in arteries and could see that there was a lot of cholesterol in there. And so he had a hypothesis that maybe in that 1908 study, maybe it was cholesterol

• 1:26:43Simon Hill?

  that was in those foods and it wasn't protein that was causing this arterial plaque to, to form.

• 1:26:52Simon Hill?

  So he ran a study again with a rabbit and he, he, he used a sun, one group were fed a sunflower seed oil and one were fed sunflower seed oil with cholesterol in it. And he was able to see that quite clearly the rabbits that were fed the sunflower oil with cholesterol dissolved into it developed the fatty streaks and the, the sort of pathogenesis that goes on to become, the pathology that goes on to become atherosclerosis. Now, that, that research then was, was really groundbreaking.

• 1:27:34Simon Hill?

  But what happened was immediately after that, some other researchers and he decided to look at replicating that study in rats and in dogs. So again, feeding dietary cholesterol to these animals and looking to see if there was any buildup of this fat in the arteries. And what they, what they found was there wasn't. And so they, they thought this was a bit of an anomaly, maybe it's just something that happens in a rabbit, which is a herbivore, and there was no further science done for quite some time. Now, the key thing that was overlooked there was that in the rabbit model, the rabbit

• 1:28:17Simon Hill?

  was fed something, it increased the LDL cholesterol in that rabbit, which then had led to the, the buildup of the fatty streak. The rat and the, the, the dog models, the reason there was no fatty, fatty buildup in the artery was because they metabolized cholesterol differently. And so the consumption of dietary cholesterol didn't increase their cholesterol levels in their blood. And so, having sort of overlooked that, and also the fact that all of this was published in Russian, it was kind of parked by the Russians there and wasn't seen by the rest

• 1:29:01Simon Hill?

  of the world. And then 20 or 30 years later is when some American researchers, Kinsel and Keys, they were looking at metabolic ward studies where they're bringing people in. And they wanted to see if they could identify what components of the diet would increase cholesterol levels in the blood. Because the idea at that point in time was that high cholesterol, serum cholesterol, was driving heart disease. And you've got to remember cardiovascular disease peaked in the 1950s. Mm hmm.

• 1:29:43Simon Hill?

  This was, you know, there was essentially a national inquiry following the President of America, President Roosevelt, he died of heart disease in 1944. And so these guys were running these metabolic ward studies, and they were able to very clearly show in humans, when you feed someone saturated fat, you increase the levels of LDL cholesterol in their blood. On the other hand, when you feed someone polyunsaturated fats, you will drive down their cholesterol. In fact, in their calculation, what they were able to

• 1:30:21Simon Hill?

  deduce was that saturated fat will increase cholesterol at a rate of around twice as much as polyunsaturated fat will lower it. They were also able to tease out that dietary cholesterol in humans

• 1:30:41Simon Hill?

  While it doesn't have as significant effect as saturated fat, it still does affect cholesterol levels. And they came up with a calculation that still stands to this day. It still stands to this day. The more saturated fats in the diet and the less polyunsaturated fats, the higher someone's LDL cholesterol levels are.

• 1:31:04Rich Roll?

  And thus incidence of atherosclerosis.

• 1:31:08Simon Hill?

  Yes. So what we know is that the higher your LDL cholesterol and the longer you're exposed to that over a lifetime, the higher your risk is to develop atherosclerosis. And, you know, there, there's an interesting study out of Spain called the PISA study. And this study essentially took 4,000 healthy adults and they used ultrasound to look at the plaque in their arteries. And these were, these were healthy adults without cardiovascular disease. And the recommendations in this country and around the world are LDL cholesterol

• 1:31:50Simon Hill?

  should be around 100 milligrams per deciliter. And so they ultrasounded all of these different participants who had varying LDL cholesterol levels. And what they found was that even at that 100 milligrams per deciliter level, which we consider to be normal, but we consider it to be normal in, in quite an unhealthy population. What they found was that at that level, 40% of people had atherosclerosis. And it wasn't until you got down to around 50, 60, 70 milligrams per deciliter, did you see people without atherosclerosis.

• 1:32:32Rich Roll?

  So a couple of observations. First, wasn't there a study done on young soldiers who had died in World War I where they autopsied them and they realized perhaps for the first time that young people had these fatty streaks in their cardiovascular system?

• 1:32:52Simon Hill?

  Yeah, it was the Korean War, I believe.

• 1:32:55Rich Roll?

  Oh, Korean War, okay.

• 1:32:57Simon Hill?

  And around 70% of the American soldiers who were they were killed from gunfire.

• 1:33:03Rich Roll?

  Right. These are like 18 to 24 or whatever.

• 1:33:07Simon Hill?

  They, around 70% of them had atherosclerosis.

• 1:33:13Rich Roll?

  And then the second thing that I wanted to bring up, you mentioned Ansel Keys. I mean, this is a guy who is legendary for his breakthrough science, but also somebody who has a scarlet letter attached to him. There's a whole narrative around this guy being a quack and why we shouldn't pay any attention to anything that he discovered and this. And this narrative is being propagated by a different dietary tribe, like the sort of carnivore and low carb community of people. So walk us through, you know, truth and fiction when it comes to Ansel Keys, where he sits in the canon of legitimate, verifiable science that's trustworthy versus this idea that he should

• 1:33:56Rich Roll?

  be dismissed for reasons X, Y, and Z.

• 1:34:00Simon Hill?

  You know, if, if, if you take a position that carbohydrates are to blame for all of disease and you blame the 1980 guidelines, which are quite notorious, you know, everyone refers to them as the guidelines that came out and told people to eat low fat and look what happened. You know, population got sicker and sicker. If you take the position that...

• 1:34:29Rich Roll?

  Never mind that people didn't follow those guidelines, but anyway, go ahead.

• 1:34:33Simon Hill?

  Yeah, we should, we should get into that. That's, that's really important. If you take that position, then you need a scapegoat. You need someone to blame. Who's responsible for this? And unfortunately, Ansel Keys is that fall guy for a lot of people and they blame him for the development of the low fat guidelines that came out in 1980.

• 1:34:59Simon Hill?

  Now, if you go back and look at Key's work, you know, I would say arguably, he has made the greatest contribution to nutrition science in the last hundred years. You know, this relationship between saturated fat and cholesterol and atherosclerosis is the most solid relationship that exists today. If that's wrong, then we need to throw out all of nutrition science. And, you know, people think that he just performed this seven-country study. But, as I just mentioned then, he started before that in the metabolic wards. He started in metabolic ward trials, very controlled settings, bringing people in,

• 1:35:41Simon Hill?

  feeding them different fats, exposing them to animal fats, to vegetable oils, and looking what happens to their cholesterol. From there, he was able to create a hypothesis. He could see that the saturated fats, animal fats, were driving up cholesterol. Now, he wanted to go out in the real world and look at populations that exist and compare those populations eating lots of animal fats with high cholesterol. What's their cardiovascular disease incidence like compared to other populations eating less animal fats with

• 1:36:21Simon Hill?

  lower cholesterol? And, you know, prior to, the seven-country study is, you know, what he's most known for. And, uh, prior to that, he, he conducted a, uh, he did a speech at a conference, and he put up on, on a chart, he put up the saturated fat intake and level of cardiovascular disease from six countries, right? And, uh, you know, people today say, look at that and say, well, he cherry picked those six countries. There was actually 22. Now, in Key's defense, he chose those six countries because that's where the best

• 1:37:06Simon Hill?

  data was. He wasn't happy with the data from the other countries. You remember, this is back in the late 1950s. So some of the population data wasn't that great. Now, the main point here is that some folks at that time who were arguing with Ansel Keys said that in actual fact, there's 22 countries. And they produced a graph which is very famous now. You'll see the six versus the 22. And the 22 didn't actually refute what Ansel Keys was saying. It just made the association a little weaker, right?

• 1:37:45Rich Roll?

  And the reason that he did not focus on those other countries was that the data was error ridden or incomplete because of reporting inconsistencies or just issues related to creating verifiable data sets?

• 1:38:01Simon Hill?

  Yeah, how verifiable it is. There were problems with diagnoses, for example, in countries and how they were categorizing the deaths for certain people. But I think what's really important is that when he went to conduct, set up the seven country study, he invited many, many countries. And this is overlooked. He's written about this. He wanted to work with established nutrition scientists in these countries. And essentially, he even invited France, which often gets brought up, and they declined. So he was

• 1:38:40Simon Hill?

  working with those that accepted the invitation and had established nutrition science centers who could conduct the research with him. It was a collaboration. And so there were... Seven countries chosen and within that there were 16 cohorts. These countries were the USA, there was Finland, there was Greece, there was Yugoslavia, which today has been separated, there was Japan, and there was the Netherlands. That's the seven countries. And then within those, some of those countries had multiple cohorts.

• 1:39:25Simon Hill?

  There ended up being 16 different cohorts. And the really nice thing about this study was that there was differences in the amount of saturated fat between these cohorts. You need that contrast. If you're just looking at lots of populations and their saturated fat consumption is very similar, then you're not providing enough contrast to see where the high versus low saturated fat consumption is affecting heart disease. So he conducted this research and, you know, was able to establish relatively quickly that countries like Greece and Japan, who had low saturated fat intake, around six to eight percent of

• 1:40:06Simon Hill?

  calories, had significantly lower incidence of heart disease compared to countries like the Netherlands and the USA and Finland, who had saturated fat intakes around 16 to 20% of calories.

• 1:40:21Rich Roll?

  Wow. So what we gleaned from that is a pretty clear picture of the relationship between saturated fat intake and heart disease incidence that holds up to this day. And the research around this relationship has only continued to kind of build on that premise.

• 1:40:45Simon Hill?

  Yeah, like that's. That was just the start.

• 1:40:49Rich Roll?

  Right.

• 1:40:50Simon Hill?

  You know, that's, there's, there's been extensive research since then. And I should add that, you know, what, another criticism that, that, that Keys often gets is that he, he was not paying attention to refined carbohydrates. And, you know, that's, that's not true. His, his own studies show that there is a relationship between refined carbohydrates and cardiovascular disease, but that association is weaker. It is weaker than saturated fat cardiovascular disease.

• 1:41:20Rich Roll?

  Hmm.

• 1:41:21Simon Hill?

  And in fact, in 1968, when, when Keys was providing recommendations for Scandinavian dietary guidelines, limiting refined sugars was one of his recommendations.

• 1:41:33Rich Roll?

  Hmm.

• 1:41:35Simon Hill?

  And he wasn't just this guy that was obsessed just with saturated fat. You know, that was very much the start of his work. And over, over the course of his work, uh, his, you know, he, he's, he's most well known for being an advocate of the Mediterranean dietary pattern. And he's the one that, that went on to describe that dietary pattern, as I referred to earlier, as a, a sort of largely vegetarian diet with, uh, you know, modest amounts of fish and, and dairy.

• 1:42:05Rich Roll?

  So when we see the carnivore diet proponents out there, the Paul Saladinos and the Sean Bakers advocating for this notion that everything you ever thought you knew about saturated fat is wrong, saturated fat is your friend, what are they hanging their hat on in terms of, of, you know, establishing that this is not harmful?

• 1:42:28Simon Hill?

  Compared to what, Rich?

• 1:42:29Rich Roll?

  I don't know, you tell me.

• 1:42:31Simon Hill?

  That's the million dollar question here. Uh, you know, there are a, a bunch of, of meta-analyses that seem to make saturated fat look okay. And you can do that depending on what you compare it to. And I said before, there's been mountains of evidence that have come out since the seven country study. And part of that has been teasing out exactly this. If you swap calories from saturated fat for calories in refined carbohydrates, then that's a lateral move. It could even increase risk of cardiovascular disease.

• 1:43:07Rich Roll?

  Yeah. And you're kind of alluding to, there was a study that garnered a lot of press that said saturated fat isn't related to heart disease.

• 1:43:17Simon Hill?

  The PURE study.

• 1:43:18Rich Roll?

  It was really, yeah, exactly. But what it really said was, maybe it's not quite as bad as we originally thought, but it's still bad. Is that a, how do you interpret that?

• 1:43:30Simon Hill?

  The way I interpret the PURE study in particular is that this was a multi-country study. And there are always some limitations when you're comparing different socioeconomic classes. And in that study, the people that were eating less saturated fat were tending to eat diets below the poverty line. And they were diets that contained a lot of refined carbohydrates, very little diversity. And sure, in a diet like that, the addition of some animal fats may improve their health. I wouldn't argue against that. But consistently,

• 1:44:10Simon Hill?

  if you look at what happens if you swap calories from saturated fat for polyunsaturated fats, like vegetable oils, or nuts and seeds, or even fatty fish, or for monounsaturated fats, or for whole grains, you see that you drive down heart disease risk. So I think the key takeaway point here is, you can make saturated fat look good. It depends what you're comparing it with. Whether removing saturated fat from your diet is healthy or not depends what you're replacing it with. If you are replacing it with nuts, seeds, fatty fish, if you eat seafood or whole grains, then you are going to be lowering your risk of heart disease.

• 1:44:54Rich Roll?

  Yeah. Another talking point that gets thrown around from those communities. I feel like they've pivoted a little bit away from the saturated fat thing. And now it's all about vilifying seed oils. Like that's become like the evil culprit in this whole thing in a very reductionist way. So walk me through that argument and kind of where things stand in terms of not just seed oils, but also the whole conversation around the health implications of of oil in the diet, you know, whether we're talking about the Esselstyn, you know, super, you know, no to low oil, plant-based diet to people who are very kind of, you

• 1:45:36Rich Roll?

  know, pro olive oil and all of that. I mean, that's a, that's a large, big question.

• 1:45:41Simon Hill?

  Maybe we start with the sort of omega six rich vegetable oil, seed oils, and then we'll go into olive oil and the vegan diet, the low fat vegan diet. You know, the, that rhetoric around omega six oils being to blame, seed oils being to blame for disease. I, it's something I've studied super closely because it really, it really intrigues me. Because I find it incredibly hard to see how someone can take that position from an evidence-based point of view. But I think this is a prime example where emotions and facts don't mix

• 1:46:22Simon Hill?

  very well. And when you're really affected by emotions, it can affect objectivity.

• 1:46:30Simon Hill?

  And so I said before, the 1980 guidelines came out. And a lot of people will say that those guidelines pushed people off of animal fats and pushed them towards seed oils and vegetable oils. Right, being a primary ingredient in ultra-processed foods. Sure, and I would be the first person to put my hand up and say that, you know, seed oils within ultra-processed foods, I don't think anyone should be eating more ultra-processed foods, but we need to remember there is much more than just seed oils in those ultra-processed foods, they're added, you know, there's added sugar and there's added salt and a whole lot of other additives. Mm-hmm, refined grains too.

• 1:47:12Simon Hill?

  That's right, so where, where does this idea that, that omega-6s, seed oils are inflammatory, are causing disease come from? Let's go back to the evidence hierarchy. So I think firstly, from an anecdotal point of view, a lot of people who believe that seed oils are bad, they've removed ultra-processed foods from their diet and they feel better. So I understand that, that's, again, that's, that's their lived experience, but I think they're wrongly attributing that benefit to, to the reduction of seed oils, when in

• 1:47:53Simon Hill?

  fact, it's just the removal of ultra-processed foods from their diet. If you look at the strongest kind of arguments for omega-6s being inflammatory, all of this is in vitro animal study science. And as we mentioned earlier, not everything that happens at that level plays out in, in humans. And we know from significant amounts of randomized controlled trials, randomized controlled trials, if, if people substitute saturated fat for vegetable oils or seed oils, they reduce their risk of heart disease. That's the first thing.

• 1:48:33Simon Hill?

  The second is that omega-6s, when you consume them, the, the body desaturates and elongates them into a biological, biologically active form, a bit like what happens to omega-3s. People have probably heard that plant-based omega-3s go through a similar pathway where they're converted to DHA and EPA. Same thing happens with omega-6s. And Along this pathway, when you consume omega sixes, which is linoleic acid, this is a fat that is quite concentrated in seed oils. Along that pathway, a fat called arachidonic acid is produced.

• 1:49:17Simon Hill?

  And the idea from a mechanism point of view is that this is a precursor to inflammatory compounds. But when we look at human intervention studies, if you feed people seed oils, you don't get an increase in arachidonic acid. You don't see it.

• 1:49:36Simon Hill?

  Secondly, if you feed people omega six linoleic acid, you do not get an increase in inflammatory biomarkers. And that's probably the most important thing for us to think about here. It just doesn't happen. Despite the putative mechanism and what you see in in vitro or animal studies, it doesn't play out in human studies. And then if you zoom right out and you look at large population studies and you look at people consuming more linoleic acid or who have higher amounts of linoleic acid in their tissues, they have lower risk of cardiovascular disease and lower risk of total mortality.

• 1:50:17Rich Roll?

  But would that not be, to play devil's advocate, another example of compared to what? Is not the conventional wisdom still, like you, you know, what I've heard for years is most people are consuming way too much omega six and it's all about the ratio or proportion of omega six intake to omega three. And we're being told to increase our omega threes and reduce our omega six to bring that into kind of proper relationship. Is that still the, still the scientific, you know, sort of perspective? Or is this new studies that have changed that?

• 1:50:52Simon Hill?

  I, I don't think that is the position today. I think that overwhelmingly, there is overwhelming evidence to, to show that that, that ratio where I do think it is important is that. The the omega six pathway and omega three pathway share enzymes. And so there is a possibility, if you have a lot of omega sixes in your diet, then you're using up all those enzymes and you may struggle to convert the omega threes from ALA to DHA and EPA. So I don't think that's been fully borne out in the science, other than to say, I think

• 1:51:35Simon Hill?

  there is some evidence, particularly people with chronic inflammation, like rheumatoid arthritis, that does seem to be a benefit for them to lower omega sixes in their diet. But overall, if you if you look, you know, at the human health outcome data, when you're feeding healthy adults omega sixes in quite large volumes, you're not dialing up inflammation. And when we look at a population level, people that are consuming a lot of these omega sixes, as I said, they do have lower risk of cardiovascular disease, lower risk of premature death.

• 1:52:12Rich Roll?

  Is that provided those omega sixes are not prepackaged in an ultra-processed food, where there's all these other factors to consider?

• 1:52:23Simon Hill?

  Yeah, I think so. And that's kind of where I land on this. I certainly, I mean firstly, I'm not sort of pro seed oils, pro vegetable oils.

• 1:52:35Rich Roll?

  Yeah, let's make that clear, because it does sound like, hey, like, no problem with omega sixes, knock yourself out with seed oils.

• 1:52:42Simon Hill?

  What I'm saying is, you know, I just don't think they're the poison that they're made out to be. I certainly don't think that we should be increasing our exposure to ultra-processed foods, but I don't think we need to generate the fear over vegetable oils and certainly don't need to to blame the increased burden of chronic disease since 1980. That's not from people swapping butter with a vegetable oil in their cooking. You know, it's it's it's a lot more complex than that. Since 1980, you know, the consumption of these ultra-processed foods has increased, you know, hugely.

• 1:53:26Simon Hill?

  And, you know, as I said, I'm not a huge sort of pro seed oil person. And, you know, particularly, you know, if someone's watching their weight, I think all oils are very calorie dense. And we need to be mindful of that. They, you know, they're, they're bringing about 120 calories per tablespoon. So they're quite easy to, to over consume. You mentioned olive oil and the vegan diet.

• 1:53:53Rich Roll?

  Yeah, I mean, within the plant-based vegan, you know, world, there are, there are sub-communities within that that are at odds with each other over the health implications of, of including something like olive oil in the diet. On the one hand, you have Caldwell Esselstyn and his camp that is very anti-oil. That's a contingent of people who are, are primarily focused on preventing and reversing heart disease. And, you know, Caldwell's somebody who's treating people, for the most part, who are very ill. Then you have, and, and he's very adamant in that perspective and has done his studies and written books about this.

• 1:54:34Rich Roll?

  And then on the other end, you have a different contingent of, of people that include, like Danielle Bolardo and some other folks who are saying, the, the science doesn't bear out the negative health implications of, of olive oil on a plant-based diet. We vilified this. There is, there is space and room within a healthy plant-based diet to include this. Where, you know, what say you, sir?

• 1:55:01Simon Hill?

  So I guess firstly, the likes of Dean Ornish and, and Dr. Esselstyn, you know, these guys are giants.

• 1:55:07Rich Roll?

  Yeah, just legends.

• 1:55:08Simon Hill?

  And, and, and they have done so much good for health across the globe, you know, reached millions and millions of people. And their diets work. You know, I, I, I am of the, of the view that there is no definitive evidence that the addition of olive oil, for example, to a plant-based diet makes it inferior. And perhaps it could make it superior in some ways. And, you know, I think if you look at, say, Dean Ornish's study, for example, I think people look at that and see, or even Esselstyn's study, that there was no oil in those studies. And therefore that must be why they got the results that they did.

• 1:55:54Simon Hill?

  But in the case of Dean Ornish, you have to realise that compared to the control group, there was many changes. It wasn't just- There were a lot of lifestyle changes that they made that were part of that. He's never tried to say otherwise. Exactly. And I mean, just from a dietary point of view, there were many changes. People increasing their fruit and vegetable consumption and decreasing their animal product consumption. And the removal of oil was just one change of many. So you would really need a third arm in that study to try and independently tease out the effects

• 1:56:34Simon Hill?

  of oil. And in fact, you would need to change the study design a little bit to remove the exercise and the stress component and all these other variables that could be affecting the outcome. So I think that there's a little bit of kind of over extrapolation from that study. And also Esselstyn's study as well, that's an oil-free diet. There are some nuances with that study that are still debated, but I don't think we need to sort of go into that. If you then zoom out and look at other studies like PRETIMED. And PRETIMED was a

• 1:57:14Simon Hill?

  study of around 7,000 people, primary prevention, so they didn't have heart disease. And they had a control group, standard care, standard diet. They had two intervention groups. These were Mediterranean diets, one with oil and one with nuts, olive oil, I should say. And they saw over a five-year period, those in the Mediterranean groups had around a 30% reduction in cardiovascular disease events.

• 1:57:47Simon Hill?

  And there was no difference between the Mediterranean group that had nuts added or the Mediterranean group that had olive oil added. So, you know, that kind of speaks to, to the fact that olive oil can be included in a heart healthy diet. You know, it's not to say that there's not going to be a future study that does look at the independent effects of, of olive oil in a completely plant-based diet and shows a difference. But, you know, at this stage, I think, you know, it's, it's kind of the least of most people's concerns. You know, the, the most important things are driving saturated fat down. We know that

• 1:58:32Simon Hill?

  the inclusion of, of polyunsaturated fats, as I spoke to earlier from those metabolic ward studies, is actually very important. These polyunsaturated fats are inherently beneficial. They will help to lower cholesterol. So their inclusion through nuts and seeds or olive oil, if that's right for you, I think is a good idea.

• 1:58:54Rich Roll?

  Right.

• 1:59:02Rich Roll?

  So when someone hits you up and says, Simon, I've, I hear everything you're saying. You make a lot of sense, but I've been on a low carb diet or I've been on a keto diet and I'm having great results. I feel great. I've lost a bunch of weight. What is your response to that? Like, how do you think about low carb diets, the keto diet, et cetera, in contrast to a higher carb, plant-based diet?

• 1:59:27Simon Hill?

  I might just add one thing to the oil. Hold that thought, because I just remembered something that I think is important. The, there are some studies showing that oil impairs endothelial cell function. You may have heard that before. And it's, these are acute studies looking at when you feed someone oil, what happens in the postprandial period after they consume that oil to their endothelial cell function. And you see that it is impaired.

• 1:59:57Simon Hill?

  And that is often science that people point to to say, hey, look.

• 2:00:01Rich Roll?

  Imperated what way? What does that mean?

• 2:00:03Simon Hill?

  Well, you get a change in blood flow, a negative change in blood flow. And so the the idea here is that the consumption of oil is negatively affecting the endothelial cell function, endothelial cells line the arteries. And if this is happening acutely, maybe it explains what's happening chronically.

• 2:00:30Rich Roll?

  Right.

• 2:00:32Simon Hill?

  But there is some, I guess, some issues with this train of thought. You know, exercise also acutely impairs endothelial cell function and so does sleep. So it's it's it's interesting, but I guess we have to to consider that not everything that happens acutely is representative of what happens chronically. And sometimes an acute stress can actually lead to an adaptation and a benefit in the in the long term. So I think that's worthwhile adding.

• 2:01:09Rich Roll?

  All right. So on to the next thing that I asked you about.

• 2:01:13Simon Hill?

  Low carb versus high carb.

• 2:01:16Rich Roll?

  Basically.

• 2:01:19Simon Hill?

  From a weight loss point of view, there is a plethora of studies that have essentially shown there is no significant benefit to either. And some of the probably the best design studies come from Professor Christopher Gardner out of Stanford. He he initially ran a study in the early 2000s called the A to Z study. And this this featured Atkins, it it featured uh the Zone Diet, the Learn Diet, and the Ornish Diet. All of these have a different ratio of macronutrients. So some

• 2:02:00Simon Hill?

  of them are low carb, some are are high carb. And 12 month trial, uh you know, by the end of that that 12 months, there was no significant difference between Atkins and Ornish. And Atkins is the lowest carb and Ornish is the highest carb. Strictly through the rubric of weight loss. This is strictly through the rubric of weight loss. And the idea with this this was, they had dieticians who would use the most prominent books, so the the Atkins book and the Ornish book at the time, to educate people on how to adopt these diets. Uh and and that's So this was done a while ago then? This is done. Books like the Zone Diet was like in the early 90s, right?

• 2:02:44Simon Hill?

  Yeah, so this was done, I think, in 2003. Uh and there was a very interesting finding, though, Rich, from this study. And that was that within the groups, so within the the low carb and within the high carb, some people did really well, and some people did really poorly. So there was this sort of wide variation. And Christopher Gardner was left thinking, well, I wonder what explains that? Why would why would some people do really well on low carb, some do really poorly, and the same for high carb? And he thought, maybe it's genetics, or perhaps it's insulin

• 2:03:23Simon Hill?

  resistance, how well your body can can utilize glucose, carbohydrates. And so he went away and got funding and ran a another study, a larger study, 600 people, again 12 months, called Diet Fits. And this study only had two arms.

• 2:03:45Simon Hill?

  The two arms were a low carb diet and a high carb diet. And he was looking at, he wanted to, he knew that what he would see in each group was some people do really well and some really poorly. And he wanted to see if perhaps these genetic markers, he was looking at three different genetic variations. He wanted to see if they would affect the outcome or if insulin resistance would affect the outcome. And very interestingly, none of that predicted who was, who was successful and who was unsuccessful in weight loss. So we're left in this position today where that is largely unanswered.

• 2:04:28Simon Hill?

  There, for some reason, some people do better on high carb and there's certain people that are doing better on low carb. And perhaps future research will, will tease out why that is. But at this stage, you know, I've kind of changed my view a little bit, I'd have to say, on, on low carb and I've softened, I think I've softened my approach a bit. If, if that works for someone, then, you know, I think that meeting them where they are is, is the better approach. And that's not to say you can't do a low carb diet in a healthy way.

• 2:05:05Rich Roll?

  Right, I mean, it's a, it's what kind of low carb, if you're doing a low carb diet that's rife with saturated fat and all these other things that we've been talking about, not so good, but there are ways of doing it in a healthy manner.

• 2:05:18Simon Hill?

  Yeah, so you can, you know, going back to that theme, the plant predominant theme, you can do a low carb diet within that theme. And instead of loading up on the, the red meats and, and the dairy, you're going to be more emphasizing the, the nuts and the seeds and, and the plant protein. And, you know, I've, since writing this book, and I, I'm not sure exactly what communities have been speaking about the book, but I've had a number of people from the low carb community get in contact with me. And what I've realized, Rich, is there are a lot of people in the low carb community who, despite what

• 2:06:04Simon Hill?

  Paul Saladino and Sean Baker might be saying about cholesterol. There are a lot of people who do believe the science. Low carbs working for them, they're losing weight. But they do believe the science when it comes to heart disease and they are fearful. You know, these are young parents, people 40s and 50s who, you know, they, they, they've found a way of eating that does help them lose weight. But at the same time, they go to their doctor and their doctor's like,

• 2:06:35Rich Roll?

  They get these blood markers.

• 2:06:36Simon Hill?

  Their doctor's like, what are you doing? You know, we need to put you on a statin. And, uh, you know, that's scary. So what I found is that there are a large number of people who are really receptive to this idea of, you know, hang on, you don't have to abandon this approach that's working for you. You can actually do it in a way that is evidence based. We can, uh, you know, keep you on this path of weight loss if that's right for you. And at the same time, we can modify the foods that are, that are in that diet in a way that will drive your cholesterol levels down, drive your, uh, insulin resistance down.

• 2:07:17Simon Hill?

  And overall, you know, not just deliver on weight loss, but also put you at lower risk of, of these diseases.

• 2:07:24Rich Roll?

  And what would some of those cornerstone foods be?

• 2:07:28Simon Hill?

  So it's, it's all about driving the saturated fat down and increasing polyunsaturated fats. Uh, you're, you're trying to cut back on, on meats and dairy in particular. And you're, you're wanting to increase nuts and seeds and, and seafood, if you eat seafood, is a much better source of polyunsaturated fats, much lower in saturated fats compared to, to meat. Um, so those are the main. Little tweaks, but also finding ways within their their diet to increase fibre as well is important. And you can do that through in a low carb manner where instead of it being,

• 2:08:11Simon Hill?

  you know, leaning heavily on the sort of starchy foods, you're really trying to increase the volume of sort of low calorie, very nutrient dense vegetables.

• 2:08:23Rich Roll?

  Right, like super low glycemic vegetables.

• 2:08:26Simon Hill?

  Yeah, so lots of cruciferous vegetables and dark leafy greens. And and so you you can easily shift this sort of animal heavy, low carb diet to a more Mediterranean style, low carb diet. And you see very quick, you know, huge improvements in their blood lipids, improvements in blood pressure. And they feel better.

• 2:08:52Rich Roll?

  But you personally eat around 50, 30, 20, right? 50% carb, 30% protein, 20% fat.

• 2:09:03Simon Hill?

  Yeah, if I was to count it out, I think actually somewhere around there, maybe a perhaps a little more fat and a little less protein than than that. But that would be kind of around around the mark. And that's what leaves me feeling the best. I'm a I'm I'm big on diet quality being more important than focusing too much on the macronutrients. The macronutrients can get can be important if you have a very specific goal. And for example, athletes or bodybuilders, etc. But I think what's more important first is the

• 2:09:43Simon Hill?

  quality of those macronutrients, the quality of the fat, the quality of the carbohydrates, you know, it's less jelly beans, more black beans, the quality of the protein.

• 2:09:55Rich Roll?

  Quote of yours, by the way.

• 2:09:56Simon Hill?

  Yeah, so, you know, where we there are a lot of people that are very anti carbohydrates, but. Carbohydrates is a, it's an umbrella term. And what matters is where you're getting those carbohydrates from. If, if they're coming from jelly beans, then you're going to run into problems.

• 2:10:17Rich Roll?

  Right, this idea, you know, in terms of, of kind of falsified narratives out there, vilifying all carbohydrates, lumping in, you know, the black beans with the jelly beans is preposterous, or analogizing fruit to diet soda, or soda, sugar soda.

• 2:10:34Simon Hill?

  Mm hmm.

• 2:10:35Rich Roll?

  Yeah. We've talked extensively on this podcast about protein, meeting your protein needs on a plant-based diet. So I don't want to belabor the point, but I haven't had you here to do it. And you're, you, you being a very strong physical specimen, I think it's worthy, if somebody's tuning into this and isn't familiar with either of us, and perhaps this is their first introduction to some of the ideas we're talking about, to at least spend a couple of minutes talking about the big protein question. Because it's still propagates in terms of people who are interested in moving towards a more plant-centric diet, but are fearful of what that implies in terms of meeting their protein needs, especially for, you know, the active people amongst that cohort.

• 2:11:21Simon Hill?

  Yeah, so this was a very large fear of mine when I was initially making the changes to my diet. And I always remind myself of that because it's, it's easy to kind of dismiss it and, and, and forget that, you know, the, the sort of general school of thought is that you get your protein from animal foods and that plants are missing protein.

• 2:11:47Rich Roll?

  Mm hmm. And to this day, when you go to a restaurant or you go to Chipotle, they say, what's your, which, what protein do you want on this?

• 2:11:55Simon Hill?

  And yeah, very rarely does that include plant protein.

• 2:11:59Rich Roll?

  Mm hmm.

• 2:12:01Simon Hill?

  Although that's, you know, it's starting to change. I think the food environment's starting to, to, to modify.

• 2:12:07Rich Roll?

  Definitely.

• 2:12:08Simon Hill?

  And we're seeing, you know, increases in, uh, plant protein options. And I was chatting with Paul Shipiro, um, a couple of weeks ago now, and he's doing, you know, exciting things with my protein.

• 2:12:20Rich Roll?

  What his company is doing right now with mushrooms.

• 2:12:22Simon Hill?

  Mm hmm. Yeah, it's crazy, you know, feeding these fungi microbes, potato and sorghum, and then producing this super protein-rich food. I tried some as well, and it's incredible. Yeah, I haven't tried it yet. You know, that's certainly the future of food.

• 2:12:45Simon Hill?

  But overall, I think there are a few aspects of protein that are somewhat misunderstood, and we can perhaps clear up some of that confusion. The first would be that plant protein is missing certain essential amino acids. And, you know, protein is made up of amino acids, they're the little building blocks,

• 2:13:12Simon Hill?

  and our body can make 11 of them, and the other nine are considered essential amino acids. We have to get them through our food. And the idea for many decades has been that plants are missing some of those amino acids.

• 2:13:30Simon Hill?

  And you hear this idea of complete protein, right? And often, you know, people speak to quinoa and soy. And I think definition here is really important. It's critical to this, because I think there's a misunderstanding of what complete protein means. I think most people think, okay, well, if quinoa and soy are complete proteins, that means that these other plants are missing amino acids. They're inferior. Yeah, or that they're just totally missing something. And that's not true. So all plants contain all nine essential amino acids. They're not missing, there just are some of those plants where certain amino acids are in lower amounts.

• 2:14:15Simon Hill?

  And so the definition of incomplete, actually by definition within the science, although it's not used this way in general conversation, is not that an amino acid is missing, it's just that it is in a a smaller percentage. And if you were to eat only that food for all of your calories, then you might run into some trouble. You might not consume enough of of a certain amino acid to meet your body's daily requirement. So you can imagine that that's that's kind of a useful definition for developing countries, places where there is food security problems.

• 2:14:58Simon Hill?

  And if someone's living on one or two foods, then that's important. But if you're eating a diet where you have a range of an abundance of food options, then really it's not that helpful. And if you're eat, so if you are eating with diversity, you will, you might be consuming, for example, grains that are low in lysine. And look, it's true, if if you were to eat certain grains and that was providing your three thousand, two and a half thousand calories, then you might, you might fall short on lysine. And the same could be said about certain beans. If you eat a certain bean for for all of your calories, you might fall short on methionine.

• 2:15:43Simon Hill?

  But beans are very rich in lysine. And when you start adding all these foods into your diet, some might be low in a certain amino acid, but the other food is really high.

• 2:15:53Rich Roll?

  Right, it's really an academic exercise, because almost no one is only eating one food.

• 2:15:57Simon Hill?

  Correct.

• 2:15:58Rich Roll?

  Unless you're like the spud fit guy who's eating just potatoes for a year, or you are in a developing country and there is a legitimate food scarcity issue. But almost everybody is eating at least two, three, five, six, seven, 10 different foods throughout the course of a day or two.

• 2:16:16Simon Hill?

  And if you're doing that, you're eating with that diversity and you're eating enough calories. You will not run into problems. You will get all of the essential amino acids that your body needs. And anyone can can run a simple exercise. Don't believe me. Download the Corona Meter app. It's a free app. Plug in a day of eating and you will quickly see that you will exceed the the hundred percent recommended amount for all nine essential amino acids. And and you'll see it's very hard not to exceed. It would be more challenging to fall short on them than it would be to consume enough of them.

• 2:16:55Rich Roll?

  Is there any validity to the argument of high quality versus low quality proteins? If we're meeting all of our essential amino acid needs, is there a difference in plant protein X versus animal protein Y beyond just the narrow lens of amino acid intake? I mean, we're, you know, like IGF-1 and all these other things that come into play in terms of the impact on our ability to, you know, build and repair our muscles.

• 2:17:26Simon Hill?

  So let's let's step back one step here. I think it's important to acknowledge that if you look at populations who are who are vegetarian or are vegan, across the board, whether you're looking at populations in North America or in Europe, people are consuming more than enough total protein. And that's that's really important. So there's a paper just out from Slovenia, Health Conscious Vegans, and these people were consuming about 1.5 grams of protein per kilo, right? And the recommendation is to consume 0.83 grams

• 2:18:09Simon Hill?

  per kilogram. That's just for everyday functioning, not if you're an athlete. If you're an athlete, it's going to be higher, in the realm of 1.2 grams per kilo up to sort of 1.6 grams per kilo. But first and foremost, these populations of people eating only plants, or almost only plants, are getting more than enough total protein.

• 2:18:32Simon Hill?

  And then the question is around protein quality. And often people wonder, well, is there a difference in bioavailability as well? And you hear about animal protein being much more superior in terms of absorption and your body's ability to utilize it. And, you know, of course, the RDA and when they did the guidelines, they had to consider this because if there was a really, really big difference, they would need separate guidelines. You know, 0.83 grams per kilo would not be for everyone. It would be for omnivores and then for vegetarians and vegans, there would need to be a separate guideline.

• 2:19:13Rich Roll?

  Right. If there was a percent, a 20% reduction in bioavailability, bioavailability, bioavailability of plant protein, then you would have to increase that up from 0.83.

• 2:19:24Simon Hill?

  Yeah, which there's not. And that's based on nitrogen balance studies, which essentially can look at the, you know, how well your body is absorbing protein. And, and these studies have been able to compare animal protein versus plant protein and, and see that there is not a big enough difference to justify different recommendations for protein requirements for different populations, omnivores, vegetarians, vegans. Now, I will say that there, there have been some studies where animal protein has been made to look quite superior to plant protein.

• 2:20:09Simon Hill?

  And there, there are a few problems with this, this research or limitations, I should say, there, there's not a problem with the studies themselves, but limitations in terms of how we can interpret them. A lot of this knowledge early on was built on animal studies, feeding them different proteins and, and measuring absorption. And, and so the physiology is different to, to us, but they can act as a useful model, particularly pigs, which have a closer digestive system to us compared to rats. But one of the biggest problems with this research is that by and large across the board, when it came to plant protein, they fed them raw plant protein.

• 2:20:55Simon Hill?

  And we know that cooking beans and grains, for example, it helps make the nutrients more bioavailable. And you know, you and I wouldn't eat a raw bean for that reason. And so what's happened is in those studies, the the the results sort of overstate the differences between the animal protein and the plant protein. Now, in more recent years, there are now human studies that have looked at properly prepared plant proteins. And in the plant proteins that they've looked at, there seems to be only a few percent difference

• 2:21:33Simon Hill?

  in bioavailability. And there's a paper by Mariotti from 2019 that summarizes all of that. And so the the current position is that, you know, there might be a slightly lower bioavailability of plant protein, but it's much less than than what had been thought in the past. And I'll add the caveat there that there is probably only around six or seven plant proteins that have been tested. So I'd love to see more research and look at, you know, hundreds of different sources of plant protein. But it it it does seem like there's there's not a significant difference or or at this stage reason to

• 2:22:18Simon Hill?

  be worried about bioavailability differences. And but perhaps more important than any of this, because let's be honest, people listening and you and I, bioavailability and percentages around absorption, that's not what matters. What matters is what happens into what happens to various health outcomes or short term outcomes in terms of strength and building muscle. And I spoke before to the clear benefits of swapping animal protein for plant protein when it comes to our long term health. You know, that this, there's there's no doubt about that. It's absolutely consistent in the literature.

• 2:23:00Simon Hill?

  In terms of strength and building muscle, this is a really interesting area. And there's a lot of emerging science here. And I'm starting to see nutrition scientists in this space who have been very adamant that animal protein is king, starting to change their tune a bit.

• 2:23:23Simon Hill?

  And, you know, I don't think it's all sort of said and done. But there is some early clues that you can still get the same benefits in terms of strength and hypertrophy from consuming plant protein.

• 2:23:40Simon Hill?

  And we need more research looking at different populations. But there's one study that came out early this year, actually. And this was a randomized controlled trial and really the first of its kind. A lot of studies in the past, Rich, that have looked at at plant protein and looking at resistance training and measuring strength and hypertrophy have looked at the addition of, say, a soy protein shake to an omnivorous diet. And versus another group who are eating an omnivorous diet with a whey protein shake.

• 2:24:19Simon Hill?

  So it's very hard to, from that study, sort of extrapolate to a completely plant exclusive diet, because their baseline diet was including.

• 2:24:29Rich Roll?

  They were already meeting their protein needs.

• 2:24:31Simon Hill?

  Yeah, and they were they were not a person consuming a vegan diet.

• 2:24:38Simon Hill?

  So it's it's it's just a different question, right? Those studies are essentially just comparing whey versus soy protein in the context of the two different people eating the same diet.

• 2:24:52Rich Roll?

  Right, I got it.

• 2:24:53Simon Hill?

  Whereas with the this latest study, it was, okay, let's actually look at at healthy adult males who are consuming a completely plant-based diet, same sort of diet you and I would consume, with a soy protein shake supplement against a group consuming an omnivorous diet with a whey protein supplement. So now we have completely plant against an omnivorous diet, how most people in the sort of resistance training industry would eat.

• 2:25:28Simon Hill?

  And we get to see is there a difference in strength and in terms of hypertrophy, lean muscle. And I should note, these were, these were healthy adults that were active, but they weren't people that had been doing resistance training for years. And there was a very important reason for that selection. Once you've been training for a very long time, it's, it's hard to

• 2:25:53Rich Roll?

  You plateau.

• 2:25:54Simon Hill?

  You plateau. So you're likely in a, in a 12 week trial, you're, you're, you're not likely to see enough differences to be able to measure whether one diet is superior to the other. So what they wanted is almost these healthy, fit people who are going to get those early newbie gains. And, and see like in this period of rapid growth, is there a difference between these different diets? So they, they brought these folks in. They, they did, I think it was 10 or 12 weeks of resistance training. This is a study out of Brazil. Hamilton Rochelle is the lead researcher. And they, what they

• 2:26:35Simon Hill?

  found was there was no significant difference at all in strength or hypertrophy. And both groups had great improvements in both. So, look, what can we say from that study? Well, we can say in, in healthy adult males, that did not have a history of resistance training, there seems to be no difference in terms of whether it's plant protein or animal protein.

• 2:27:01Rich Roll?

  Yeah. No difference in terms of your ability to make gains in a certain period of time.

• 2:27:06Simon Hill?

  That's right. And, you know, is that the same for an elderly population who, who, as you, as you get older, you develop anabolic resistance. And so your, your ability to generate muscle to, to promote lean muscle growth is harder. That, you know, there are certain ideas out there, for example, that animal proteins might be better in that population because of differences in amino acids, particularly being more concentrated in leucine.

• 2:27:41Simon Hill?

  But these were the same ideas that were held not too long ago about healthy adult males. And what we're starting to see here, and I didn't mention this about that study. They set both groups at 1.6 grams per kilogram of protein intake. That seems to be the sort of threshold. If you want to absolutely maximize muscle protein synthesis, that's the level you need to hit. Once you go above that, you don't really see any extra improvement.

• 2:28:14Simon Hill?

  So, you know, that's, that's kind of where science is up to today.

• 2:28:18Rich Roll?

  Yeah, the current state of affairs. I mean, that's, that's encouraging and I would like to see that study with elderly people as well. Because I have heard that like, once you reach a certain age where your body becomes, you know, less able to hold on to that muscle mass and make those gains. That protein then becomes a much more important, you know, component of your diet.

• 2:28:41Simon Hill?

  And that's coming, those researchers are going to do it. But, you know, having spoken to the researchers, and I think they were a bit surprised by the results of that study. You know, I'm not so sure there, there is confident going in to, to studying the elderly now in terms of animal protein being vastly superior. Because in this study of, of healthy, young adult males, even though the protein was matched at 1.6 grams per kilo, and they, they had no differences in strength or in lean muscle. The plant-based protein group did consume significantly less leucine.

• 2:29:23Simon Hill?

  Right, so, so they, they were still able to achieve the same health outcomes despite the lower concentration of leucine in their diet. And I think that's an, that's an important thing.

• 2:29:35Rich Roll?

  Right, so what is, what does that tell you? What do you extrapolate from that?

• 2:29:38Simon Hill?

  Well, I extrapolate that.

• 2:29:42Simon Hill?

  There might have been, there may be an overemphasis on the importance of focusing in, dialing into leucine. I think it's no doubt is important, but, but most important is total protein. And if you're hitting that 1.6 grams per kilogram mark, I don't think there is added benefit of just continuing to dial up leucine, you know, further and further. And in fact, if you speak to longevity scientists, the likes of Walter Longo, that these guys are going to say, you know, one of the inherent benefits of plant protein is that it's exposing you to lower amounts of leucine and methionine, these amino acids

• 2:30:23Simon Hill?

  that are thought to activate, you know, not just muscle growth pathways, but also aging pathways.

• 2:30:30Rich Roll?

  It's so interesting. It's also fascinating to see traditional kind of gym rat, bodybuilder type guys pivoting towards plant-based, you know, protein powders instead of the traditional way. Like they're not, these are not plant-based people. They're not vegan people. They're probably eating their chicken and their broccoli and doing the standard routine, yet they're still going to the pea and the brown rice and the, you know, various new products that are coming on board as opposed to just doing the whey thing like traditionally they always have.

• 2:31:04Simon Hill?

  Yeah. And some of that is, is probably down to the way that whey makes certain people feel.

• 2:31:10Rich Roll?

  Yeah.

• 2:31:10Simon Hill?

  And there's a lot of lactose intolerance out there. So, you know, it's, it's nice to see that change in the community. And, and I think this study in particular is giving people more and more confidence, right? Because people need the data. You know, there are a lot of great anecdotes out there and you can see a lot of people like yourself who have had very, very successful careers in various forms of, of performance, the performance world, be it endurance or be it resistance training. But now to have some, some actual data. Is giving people more confidence to lean into this and explore a bit further.

• 2:31:55Rich Roll?

  Yeah. So Simon, I want to switch gears and cover some other terrain, but before we move off of human health, perhaps some final thoughts on LDL and the carnivore diet, because there's a lot of people out there who are being influenced by certain quote unquote influencers with respect to this meat heals perspective of diet and nutrition. So let's just kind of put this to bed.

• 2:32:23Simon Hill?

  Yeah, so I am extremely concerned. I think would be a nice way of summarizing,

• 2:32:33Simon Hill?

  you know, what we're seeing with people adopting the all meat diets, you know, certainly, and I mentioned before that a number of people in low carb community have reached out to me and some of these have been people that have been eating a completely carnivorous diet. And it cannot be denied that you can get good short term results.

• 2:32:55Rich Roll?

  Especially if you're moving off of a standard American diet, you are going to experience, you know, some pretty immediate changes in how you feel.

• 2:33:03Simon Hill?

  Right. And, and, you know, speaking back to that Stanford study and the microbiome, you know, it's, it's not sort of far fetched to understand that perhaps there is a certain amount of microbiome disruption where the addition of plant foods is uncomfortable for people. And a carnivore diet is essentially, it's a strict elimination diet. And so if, if, if these people, even if they're trying to eat healthfully, are introducing certain plant foods and it's rubbing up their inflammation and making-

• 2:33:37Rich Roll?

  Especially, yeah, sorry to interrupt, but you're, if you've been eating strictly carnivorous, you're seeding your microbiome with a certain type of microbiota, right, that feed on that type of food. And you're lacking the diversity to be able to create a healthy environment for the plant microbiomes to propagate and that you'll, you'll have digestive issues, you'll have inflammation and all the like.

• 2:34:04Simon Hill?

  Yeah. So you, you know, I see it as a bit of a Band-Aid. If, if someone- Is in a state of chronic inflammation and their gut is very inflamed. Removing a lot of foods does work. We see it, you know, the low FODMAP diet, for example, which is a specific diet for people with IBS. You're removing the triggers. Now, the problem is the food that you're removing is not unhealthy. It's just that your microbiome is not set up in a way that allows you to derive the benefits of that food. Mm hmm. So completely removing those foods from your diet and doing something like adopting a carnivorous diet. It could, in the short term, make someone feel a bit better.

• 2:34:47Simon Hill?

  The problem is because you're removing all of this prebiotic substrate, you're starving those bacteria. So you're going to, as you say, over time, you know, lose more and more diversity and you're not getting all of those benefits that we spoke about before. With regards to the production of these short chain fatty acids, these postbiotics, that then, you know, keep the gut lining intact and provide huge benefits, both locally in the gut and also downstream. You know, these metabolites are lowering the risk of colorectal cancer. Mm hmm. They're driving down inflammation throughout the body and, you know,

• 2:35:31Simon Hill?

  protecting us against things like neurodegenerative diseases. So there's a Band-Aid solution here where you get this short term benefit. What I think is being overlooked is that chronic diseases have a long latency period. You know, they bubble away under the surface for a while. And, you know, you might experience chronic disease in your 40s or 50s or 60s. But by and large, the lifestyle that you were leading 10, 20, 30 years ago has had a lot to do with the development of that chronic disease. You know, you spoke to the soldiers from the Korean War.

• 2:36:13Simon Hill?

  They were young. They were laying down the pathology of atherosclerosis.

• 2:36:19Simon Hill?

  So my fear is it is this sort of short term Band-Aid solution. And my biggest fear with it is that it sends LDL cholesterol through the roof. I'm talking, I said before, 100mg per deciliter is like, it's considered the kind of recommendation, you know, here in, in America and in Australia. But as I said, really, you've got to get down to 60 or 70mg per deciliter where you don't see atherosclerosis. And here's the really, really interesting thing, Rich. Lauren Cordain, he wrote the Paleo Diet book.

• 2:36:57Simon Hill?

  He also published a, a paper that goes into what is, what is a healthy LDL cholesterol level? This is coming from the father of the Paleo Diet. And he, he went through and he looked at LDL cholesterol of primates and of hunter gatherer tribes, where there is low incidence of, of atherosclerosis. And his conclusion in this paper that he wrote, the father of the Paleo Diet, was that human LDL cholesterol needs to be at 50 to 70mg per deciliter in order to avoid atherosclerosis. So this is coming from him. And you might think, well, hang on, he's advocating for the Paleo Diet.

• 2:37:42Simon Hill?

  Then how can he be also saying that LDL cholesterol should be low? And a lot of this comes back down to what the Paleo Diet is versus how people are doing it.

• 2:37:52Rich Roll?

  Yeah. And, and so- That's a very good point, yeah, because for, yeah, it's, it's, it's not exactly the way that it's been massively adopted.

• 2:38:00Simon Hill?

  That's right. And the Paleo Diet, if you look how, at how Lauren Cordain, what he recommends, you know, it, it's, it's talking about meats that are very low in saturated fat. If you went back and looked in the Paleolithic era and you look at woolly mammoth, or, you know, these types of meats that would have been eaten then, they're more equivalent to venison and antelope, which are very low in saturated fat and higher in polyunsaturated fats. That's actually ironic in itself because those people that are, that are blaming polyunsaturated fats in seed oils are overlooking the fact that meat from the Paleolithic era was very rich in polyunsaturated fats. But-

• 2:38:47Simon Hill?

  Overall, Lauren Cordain, his recommendations is for a diet that's low in saturated fat, even though he speaks about the inclusion of animal foods. He talks about that being more consistent with the type, the quality of meat that people were eating back then. And he talks about the importance of a very high-fiber diet. In fact, he mentions that many of these people were eating over 100 grams of fiber a day. So I think that's very important for people to understand that the paleo diet was not developed as this high saturated fat, animal-rich diet.

• 2:39:27Rich Roll?

  Yeah, but the carnivore diet is something altogether different. It has its roots in this kind of ancestral ideology, I suppose. But part and parcel of the philosophy of the carnivore diet, is it not, is that saturated fat is your friend. We talked about that. But also, these high LDL markers are something that you should not concern yourself with. Because you see a lot of that, because people are having these elevated numbers, including Sean Baker, who shared it on Rogan, etc. And in response, they just say, "Well, that high number isn't relevant in the traditional way that we've considered it in the past.

• 2:40:09Rich Roll?

  Because I'm doing my diet in this way, it's somehow buffered or ameliorated by dint of the fact that I'm only eating meat." So, well, you understand, at least, if you were them, like, how you would articulate that, and then let's kind of deconstruct it.

• 2:40:29Simon Hill?

  So, I mentioned before that saturated fat, increasing LDL cholesterol, increasing risk of atherosclerosis and coronary heart disease is the most substantiated relationship in science, in nutrition science today, without a doubt. And so much so that in 2017, a cardiologist by the name of Brian Ferentz, he co-authored a paper which very clearly states that LDL is causal in the progression, the development and progression of atherosclerosis.

• 2:41:07Simon Hill?

  There are some very interesting things in that paper that he walks through and let's quickly go through those. You know, there is some genetic mutations that see people with genetically high LDL cholesterol, heterozygous familial hypercholesterolemia and homozygous and hetero if you inherit one of those genes from one parent and homo if you inherit both. The latter unfortunately leading to much more rapid development of disease. But if

• 2:41:45Simon Hill?

  you have FH as it's called in short, then particularly if it's the homozygous form, you know, if you're dealt that genetic card and you have high LDL cholesterol from birth, you know, these are people that have LDL cholesterol between 500 and 1,000, right? Which is where we're seeing people in the carnivore community. If you are-

• 2:42:07Rich Roll?

  Literally, you know, five to 10 to 15 times higher-

• 2:42:12Simon Hill?

  I think Paul Saladino's is 700.

• 2:42:14Rich Roll?

  700, where Cordain's saying-

• 2:42:16Simon Hill?

  50 to 70.

• 2:42:19Rich Roll?

  50 to 70.

• 2:42:20Simon Hill?

  Right? And these, you know, people that inherit this, if they're not treated with statins, it's very, very common for them to develop cardiovascular disease in their teenage years and die in their twenties or thirties. Right? And that's obviously very, very sad today with the progression of statins, you know, these people are living much longer. So that's, that's a first thing that I think is, is interesting. The second is that there, there is a type of science, we didn't discuss it before, called Mendelian randomization.

• 2:42:58Simon Hill?

  And this is science that really has, has become, I guess, popular or more commonly used in the last five to 10 years. And thanks to improvements in our understanding of genetics.

• 2:43:14Rich Roll?

  Mendelian in the Gregor Mendel sense?

• 2:43:18Rich Roll?

  I'm not sure.

• 2:43:19Simon Hill?

  I'm not sure of the origin.

• 2:43:20Rich Roll?

  He's like the original guy doing plant hybrids and working in genetics.

• 2:43:25Simon Hill?

  Well, it could well be. I'm not sure of the origin, but what it speaks to is these studies are like nature's randomized controlled trial. There are over 50 genetic mutations which lower LDL cholesterol. Right? If, and if you're dealt that card and you have lower LDL cholesterol, you have significantly lower risk of developing coronary heart disease through your life. And because this is occurring, you know, as you're being made by your mother, you know, it is nature's randomized controlled trial. And so we can see very clearly, what's really interesting about this is that these

• 2:44:11Simon Hill?

  single nucleotide polymorphisms is what they're called, right? There's 50 of these or more is that they all lower LDL cholesterol by different amounts, right? But if you are to standardize how much they lower LDL by, right? They all have the same order of effect on coronary heart disease, which means that it's very, you know, it's highly likely that this is a causal link, right? We're talking about true cause and effect.

• 2:44:46Rich Roll?

  Between elevated LDL and atherosclerosis.

• 2:44:50Simon Hill?

  And it's a linear relationship. The lower you get LDL cholesterol down based on whichever genetic variant someone has, the lower their risk of coronary heart disease. Now, to add more evidence onto that, then we have lots and lots of statin trials. And there's, there's some anti-statin rhetoric out there, but it is, you know, it's, it's, it's so clear in these studies that when you get, when you lower LDL cholesterol through the use of either a statin, azetimibe, or PCSK9 inhibitors, these are different drugs

• 2:45:35Simon Hill?

  are running on, acting on different pathways that all lower LDL cholesterol.

• 2:45:41Simon Hill?

  No matter which one you look at, they all significantly lower coronary heart disease. And once you get someone's LDL cholesterol down to about 70 mg per deciliter, which is 1.8 millimoles per liter with statins or with PCSK9 inhibitors, that's where you stop, you see that the progression of atherosclerosis stops and you can start to see some regression. So we have evidence from people who have genetically high LDL cholesterol. These people, if they're untreated, will develop atherosclerosis in their teens. We have evidence from people who have genetically low LDL. They're significantly

• 2:46:26Simon Hill?

  protected against heart disease. We have these statin trials, which you see as a lower LDL cholesterol, you drive coronary heart disease risk down. And then on top of that, we have all of the observational research. You know, there's a meta-analysis, the prospective studies collaboration that included 50-plus studies, 12 million-plus person years follow-up in that study. And it clearly shows in these cohort populations, lower LDL cholesterol, lower risk of coronary heart disease.

• 2:46:59Rich Roll?

  So when Paul Saladino with his insanely high LDL says, don't sweat it, don't worry about it, you don't need to concern yourself with this, how is he scientifically substantiating that?

• 2:47:16Simon Hill?

  I don't think he is. I think that it's, you know, it's inconvenient for him that LDL is, has been shown to be causal in the development of heart disease. And I've never seen him be able to substantiate that, other than the fact he will say that his coronary artery calcium score is zero, right? But we know that people with a coronary artery calcium score of zero can still have atherosclerosis and can still suffer from a heart attack. So for me, you know, the evidence is overwhelming. The lower your LDL cholesterol and the more years you're exposed to that low level of LDL cholesterol, the better.

• 2:48:02Rich Roll?

  Enough said on that. I want to switch gears and explore a couple of other things. We've been going on for a while here. Obviously, there are different motivations and onramps for people who are interested in the plant-based diet or becoming more plant-predominant in their lifestyle. We've explored the human health piece quite extensively today, but of course, there are other motivators, the ethics of our food choices and how that implicates planetary health more largely, which of course also brings up the issue of the environment and the health implications planetarily for the choices that we're making about the foods

• 2:48:45Rich Roll?

  that we eat and the food products that we choose to purchase with our buying power. So let's talk a little bit about that, maybe start more broadly with the idea of how these dietary choices are affecting. Like, we're in a climate crisis right now. It's incumbent upon all of us to take greater responsibility for the choices that we make daily. How does the plant-based diet figure into this equation of being more ecologically responsible?

• 2:49:17Simon Hill?

  Well, we've turned this place into a giant farm.

• 2:49:24Rich Roll?

  That's my second favorite quote of yours, by the way.

• 2:49:28Simon Hill?

  And that's had huge effects on greenhouse gas emissions. Currently, agriculture is responsible for 25% of the world's greenhouse gas emissions. It's had huge effects on biodiversity loss and deforestation. Agriculture is the number one cause of deforestation throughout the world, and with that, we're losing these precious parts of the natural world that really are our ally in fighting climate change. It's the single greatest user of fresh water.

• 2:50:09Simon Hill?

  Um, you know, agriculture is, is uh resulting in ocean acidification. It's resulting in the uh eutrophication and hypoxic conditions in certain bodies of water that result in the algal blooms. And overall, if you are to, to look at agriculture, I think one of the most powerful statistics is 50% of the habitable land on Earth is used today for agriculture. And of that, 83% of that is used for animal agriculture.

• 2:50:51Simon Hill?

  Yet it only returns us with 18% of our calories.

• 2:50:55Rich Roll?

  Hmm.

• 2:50:56Simon Hill?

  And is responsible for two thirds of agriculture-related emissions.

• 2:51:01Rich Roll?

  Yeah, so purely from an academic perspective, this is a highly inefficient farm that we're running, if the planet is indeed a farm.

• 2:51:08Simon Hill?

  So we have kind of, uh, I guess, uh, two parts to this. The, the factory farming of animals is very inefficient because it requires large amounts of land to grow crops. And uh, the feed conversion ratio is not great. Like to, to produce and, and to produce animal products, you have to grow these animals. And the larger the animal, the higher the, the basal metabolic rate. You know, it's the energy that that animal's burning just to be alive. Uh, and so with that, what happens is we lose a lot of the calories that we feed in to the system.

• 2:51:47Rich Roll?

  So to, if you use like a combustion engine as an analogy, you put gasoline in and not all of that energy gets converted into forward motion of the car. Some of it is cast off by heat, et cetera. Similarly, when we're taking all of these crops, we're feeding them to animals, not all of that is converted into potential energy that's consumed by humans. A lot of it is lost. Like it's just highly, high, if you were an alien who came to Earth and, and said, "Show me how you make your food," and we showed them, they would say, "This is total insanity."

• 2:52:24Simon Hill?

  And you know, food waste is important, right? And seventeen percent of the world's calories are wasted. And and we we absolutely have to focus on that because that that's calories that could be ending up in bellies. And it's also a big contributor to greenhouse gas emissions. But what's overlooked is that the the biggest area of food waste is within animal agriculture. It's the waste of the calories that we're feeding into this inefficient system. Uh, and to give uh you an idea of of the efficiency or lack of efficiency. If you feed a hundred calories into a cow, you'll get forty calories of milk out the other side. So you'll lose sixty percent.

• 2:53:04Simon Hill?

  If you feed a hundred calories into a chicken, you'll get twenty calories of eggs out the other side. So you're losing eighty percent. If you feed a hundred calories into a pig or a chicken, you'll get about ten calories of meat out the other side. So in that example, you can think, you know, if you had uh for one chicken burger, right? You could essentially make ten black bean burgers. You know, that's that's the difference we're talking about here in terms of you know, efficiency and what we're wasting. Uh, and then beef, red meat is the the least efficient of all.

• 2:53:48Simon Hill?

  You feed a hundred calories into a cow and you get three calories of meat out the other side. Now, often when I speak to this, people say, well, I only eat the the grass fed beef. And you know, that's that they're not feeding them feed crops. They're out grazing. Um, and that's true. But the the biggest problem with grazing is the amount of land that that it's using. And uh, you know, in order to um to make space for that industry, which provides very few calories, we have to clear a lot of land. Uh, and there's um a really interesting paper from twenty eighteen, Tim Searchinger.

• 2:54:35Simon Hill?

  That has gone back and looked at today's grasslands and at least forty-one percent of them were forests or woody savanna not too long ago. And globally right now, still to this day, the number one cause of deforestation is animal agriculture.

• 2:54:55Rich Roll?

  Right. So I could do a four-hour podcast on the environmental implications of animal agriculture and the impact of a pivot to a plant-centric diet in terms of the ecological impact. We don't have four hours, so I want to focus our remaining time on the conversation around regenerative agriculture, because I think there's a lot of confusion here. I've hosted people from this arena on the podcast. We're both friends with Ryland Engelhardt, who's behind the Kiss the Ground movement and the Cafe Gratitude restaurants. I've had John and Molly Chester from Biggest Little Farm on here.

• 2:55:37Rich Roll?

  I have a lot of respect for people who have devoted their time and energy towards the regeneration of our soils, because I think this is crucial. It's a crucial piece in redressing climate change and pivoting from a consumptive society into a regenerative one. But I also think there's a lot of misunderstanding, as I said, and also greenwashing when it comes to how we're understanding what exactly it is that we're talking about with respect to regenerative agriculture. I think there's a lot of well-intentioned, but perhaps misconceived narratives about this, so I want to parse truth from fiction when it comes to what we're talking about

• 2:56:20Rich Roll?

  with regen ag, what exactly can be accomplished, what is getting overlooked and what the inherent flaws are when it comes to the claims being made by the holistic land management cohort of advocates.

• 2:56:38Simon Hill?

  Gosh, big question. So, you know, I am a huge proponent of regenerative agriculture overall. I think it makes a lot of sense. I, I think that we certainly need to consider soil health. I, I think definitions are important here and also looking at what the science says, because it is an area like the diet wars where emotion can, can affect the interpretation of, of science. And so I think there's a little bit of, of science

• 2:57:17Simon Hill?

  to go through here as well. Regarding definitions, you know, regenerative agriculture is really nothing new. You know, a lot of the practices, be it polycropping or intercropping, you know, or cover cropping, these are. Those are ancestral practices. What's new is industrialized farming. That's right. And, and so a lot of, you know, regenerative agriculture, I guess, in some ways, it's, it's become a bit of a buzzword, but I do think it's important for people to understand the roots of many of these practices are from First Nations land

• 2:57:59Simon Hill?

  management. And regenerative agriculture overall is, is not the same as regenerative beef. Regenerative beef is one practice, this holistic grazing within a whole plethora of regenerative agricultural practices. Good point. And, and so there have been, you know, many, many First Nations people around the world that have improved soil without animal integration, using polycropping, cover cropping, green manure, et cetera. So I think that's an important point, because I think sometimes when people think of regenerative agriculture, they immediately think of regenerative grazing.

• 2:58:44Simon Hill?

  I don't think that there's much debate at all about polycropping and intercropping and covercropping. I think that's generally accepted across the board, that those practices are much better for promoting biodiversity and improving soil health. I think where-

• 2:59:00Rich Roll?

  And sequestration.

• 2:59:02Simon Hill?

  And sequestration, right? I think where there is dispute is around regenerative grazing. And I believe, and I've had a number of people on my show to talk about this as well, from both sides.

• 2:59:17Rich Roll?

  Right. I should point out, so I don't forget, you've done a number of podcasts with Nicholas Carter, and those are, I don't know, three or four with him? I mean, those are fantastic. So we're not going to be able to get into, you know, the super nitty gritty of all this, but everybody should go listen to Simon's conversations with Nicholas on his Plant Proof podcast, because it's very-

• 2:59:39Simon Hill?

  You should have him on. He's an incredible environmental researcher, scientist. But I guess, you know, big claims require big evidence. And the, you know, the, there have been some wild claims made about regenerative grazing over the years. Alan Savery, most notably. You know, he's well-known for a YouTube TED Talk, and he said this was the key-

• 3:00:07Rich Roll?

  That really kicked off this whole thing.

• 3:00:08Simon Hill?

  He said this was the key to reversing climate change, you know? And his idea is that he believes through his practices that you can sequester an enormous amount of carbon, right? And that would be amazing. Imagine we could draw down, you know, all of this carbon that has, you know, that has been emitted since the Industrial Revolution, get it into our soils, and cool the planet. That's a, that is a great story. Now-

• 3:00:38Simon Hill?

  Where does the science lie? That's ultimately what we should be most concerned with. And the the science doesn't stack up with it with these practices being a net carbon sequestering practice. So it's true that you can sequester some carbon, absolutely.

• 3:01:01Simon Hill?

  The problem is that when you are are accounting for methane emissions and nitrous oxide from the animals, the the net of the net position is one of greenhouse gas emissions. And there was a big report done from out of Oxford University called Grazed and Confused by Dr Tara Garnett. And she she walks through this, the fact that, you know, you can probably offset about forty to sixty percent of emissions. But even then, over time, what happens is the soil becomes saturated with carbon.

• 3:01:42Simon Hill?

  And so over over the over the years, you're sequestering less and less carbon, but you still have the same amount of methane and nitrous oxide emissions. So the practice is becoming less net sequestering over time.

• 3:01:54Rich Roll?

  Right, the livestock themselves being the emitters. But also, part of that report was it not this idea that the sequestration is not indefinite, but time sensitive in that it it's not permanently sequestered in the soil.

• 3:02:10Simon Hill?

  That's right, so it can be reversible.

• 3:02:15Simon Hill?

  And, you know, still to this day, and it is somewhat frustrating, you know, I actually, I think that that some regenerative grazing, like, let's say, we were moving to a world where everyone was adopting very plant predominant diets and the only beef production was regenerative grazing, I think that's a great result for the world.

• 3:02:39Rich Roll?

  Sure.

• 3:02:40Simon Hill?

  What I've noticed is from this industry, there doesn't seem to be a message about reduction. It seems to be a message about it's not the cow, it's the how. And that's a nice message to the mainstream who perhaps don't want to change their meat consumption. They don't have to. They can just change where it's come from.

• 3:03:02Rich Roll?

  There's an intellectual dishonesty with advocating for a solution premised on more grazing without the counterpart being this is all contingent upon everybody moving to a more plant predominant diet because by dint of sheer land availability, this model cannot scale to meet global meat demand as it currently stands. You're correct in that if everybody pivoted to only eating beef that was grass fed and grazed on regenerative land such as this, we would be in a much better state. But it's a mathematical impossibility

• 3:03:46Rich Roll?

  to meet global meat demand using this model. So something has to change. And as much as I admire the people behind Kiss the Ground and what they're trying to communicate, I think there's a lot of good in that movie. I feel like it overlooked or gave short shrift to a very important point, which is that no matter what, no matter how efficacious this model is, it will still all demand that we reduce our meat consumption.

• 3:04:17Simon Hill?

  And the key point being here, why do we need to reduce our meat consumption? Because we need to free up land. We need to produce more calories from less land and restore vast amounts of land back to wild ecosystems.

• 3:04:35Rich Roll?

  Right. And those wild ecosystems, forests, et cetera, are actually better at sequestering carbon than a grazed regenerative farm would be.

• 3:04:46Simon Hill?

  Yeah. So this is a really interesting point, too, because there is this sort of prevailing idea, I guess.

• 3:04:56Simon Hill?

  From people within holistic grazing that you need the animals to regenerate the land. And that's, that's not true. There, there is a meta-analysis, uh, 2020, which look, which specifically looked at what happens to biodiversity when you include livestock versus excluding them.

• 3:05:19Simon Hill?

  And they specifically showed that when you exclude livestock from land, you get greater returns in biodiversity, increased numbers of herbivores, you restore the predator prey relationship, you increase the number of introvertebrate pollinators. Um, so the, why I, I believe that the, the solution to this, Rich, is that until there's an incentive for the landowner to practice conservation, like, let's think about regeneration and, and just drop agriculture off the end of it for a moment. I understand that, you know, farmers and landowners need

• 3:05:59Simon Hill?

  to make an income. And I think the grazing aspect is, uh, is, is a result of economics. And Well, it's a, it's a result of incentives or a mis, a misalignment of incentives. And in New Zealand, uh, they, they have a, an incentive to, uh, afforestation. So converting, um, grasslands into forests. And it's now got to a point, so 2020 paper that just, uh, or 2021, um, it's now got to a point where landowners, uh, it, it, the, the more economical choice is to practice tree planting and afforestation than, uh, livestock grazing.

• 3:06:42Simon Hill?

  How did they create that incentive structure? Well, they are valuing carbon drawdown and biodiversity. And so, uh, I think that this is, this is sort of critical to solving this is, uh, our mindset. You know, if you, if you go back to the First Nations people, you know, something that, that we can learn from, from that. Their culture is living in harmony with the environment, being stewards of the environment, being guardians of the environment. And it's a different approach to looking at land and thinking about what value can I extract from that in the form of calories?

• 3:07:27Simon Hill?

  And the the New Zealand government, what they have done is they have placed value on the carbon, on carbon storage. And so, you know, you you you create a situation where the owner of that land stands to make more money by by practicing carbon farming as as as opposed to livestock grazing.

• 3:07:51Rich Roll?

  Hmm. Yeah, we need some fundamental changes from the top down here as well as from the bottom up. The farm bill being one of them. I know Ryland's very active in doing some advocacy around the next vote that's taking place, I think, next year. And we do need a better incentive structure because these farmers are well intentioned and they just want to make a living and they're just trying to get by. So how can we create a system that drives them towards making that regenerative choice in a way that's restoring our land, protecting our soils and, you know, promoting the the increase in in biodiversity, you know? It always goes back to that analogy with the microbiome, like these are all microsystems

• 3:08:36Rich Roll?

  and macrosystems that mimic each other in terms of how health outcomes are produced. And it starts, you know, at the at the very micro level and scales up from there.

• 3:08:47Simon Hill?

  There's a a wonderful documentary called Rewilding a Mountain. Have you heard of Heart Mountain?

• 3:08:56Rich Roll?

  Oh, is this in China? There was there was they did something similar in China, too. You know what I'm talking about?

• 3:09:01Simon Hill?

  Yeah, I believe they did.

• 3:09:02Rich Roll?

  But this is different?

• 3:09:03Simon Hill?

  This is in Oregon, I believe, Heart Mountain. And it's a it's a documentary that looked at a 20-year rewilding project. The land manager at the time consulted scientists and they said to him, you have to remove livestock. And, you know, all the riparian areas were completely damaged, the the the birds had left, the the land was very degraded. You know, a lot of degraded land around the world today is through overgrazing. And, uh, you know, this documentary steps through what happened. Uh, and you see the pronghorn antelope come back and that predator prey relationship

• 3:09:45Simon Hill?

  comes back and you see the, the grasslands grow and it's not just this kind of mono grassland, but it's native grasslands that, you know, and that's, that's an important point. Native grasslands are actually different to a lot of these grazing grasslands. Um, they support a, a, a very diverse range of herbivores. Um, and so that's a, that's a nice, I think, documentary for, for people to, to watch if they want to see what happens when you exclude livestock from the land. Um, and this is, this is just critical to us solving the, the, the climate change problem, uh, in terms of agriculture is rewilding

• 3:10:29Simon Hill?

  a lot of land, uh, and, and producing more calories from, from less land. And, you know, sometimes I hear of this idea of marginal land. I'm not sure if you've heard of that.

• 3:10:41Rich Roll?

  Hmm.

• 3:10:42Simon Hill?

  Um, and the, the idea with marginal land is that, uh, you know, this land, um, you can't do anything with it except for graze cattle on it. Um, but that's not true. That's, that's if you're looking at it from an extraction of calories lens. There's nothing marginal about that land to the animals and the ecosystem should you regenerate it and...

• 3:11:07Rich Roll?

  Yeah, marginal is, that's a subjective assessment, you know, only by, by virtue of how valuable it is to us.

• 3:11:13Simon Hill?

  So I think if we can, uh, you know, change that, that mindset and from a less kind of, uh, dominating mindset and, and, uh, more to practicing conservation and get the incentives in, like New Zealand, this is happening now around the world, um, then, uh, you know, farmers can be a key part, play a key role in, in helping to heal the planet.

• 3:11:41Rich Roll?

  Hmm. And imagine, uh, I would imagine that, you know, if you can create that sort of structure for these farmers, just how much more, um, fulfilled and purpose-driven they would feel as stewards of the land rather than as extractors. Yeah.

• 3:12:01Rich Roll?

  Well, I think we've gone, we've gone over three hours today, dude. We could go another

• 3:12:06Simon Hill?

  So much more to say.

• 3:12:07Rich Roll?

  My outline, I think we did two things on my entire outline.

• 3:12:12Rich Roll?

  But I'm not letting you go without congratulating you on the new book. This really is like the ultimate primer, just chalk a block with accessible tools that walk you through everything that we talked about today and so much more with respect to how to be more plant predominant and understanding, you know, all the hows and whys behind it. I know years of your life went into this. When I was in Australia that January, you were writing it then, and that seems like a past life. So.

• 3:12:44Simon Hill?

  You gave me some great tips, actually.

• 3:12:45Rich Roll?

  It's finally reached North American shores. It's coming out September 30. What's the date?

• 3:12:52Simon Hill?

  November 1st.

• 3:12:53Rich Roll?

  November 1st. Got it. We've calendared this to go out right around the same time. So kudos on that. Everybody should check out Simon's podcast, Plant Proof. And beyond that, plantproof.com is an incredible resource with tons of articles that are freely available where you can kind of learn the nuts and bolts of how to do this properly. And everything I might add is, or nothing I should add about Plant Proof or this book is being monetized by you, basically. This is stuff that you make freely available and the proceeds of the book are being directed to charity. Am I correct?

• 3:13:36Simon Hill?

  Yeah, maybe we should finish this on a nice, optimistic, I got some good news last night.

• 3:13:41Rich Roll?

  What's that?

• 3:13:43Simon Hill?

  The Daintree Rainforest in Australia, which is, has been, you know, threatened through deforestation over a number of years. It's the world's oldest tropical rainforest, one of the most biodiverse places on earth. And it's a world heritage site now. Um, and overnight, uh, there was a, um, an agreement made between the government and the First Nations people that, that are from that area. Um, and, uh, they have been, uh, granted the land to be the custodians of the land. So it's going to be handed back to them to be under their care. The, uh, Kuku Yulangi people, Eastern Kuku Yulangi people.

• 3:14:27Simon Hill?

  Um, so this is a, you know, it's a small win. It's a hundred and sixty thousand hectares though, that, um, will now be protected, uh, under their care and along with Uluru and Kakadu, uh, in Australia. So, um, I work to that and that's, that's incredible because that means, you know, this, this wonderful rainforest will be protected and, and their culture, um, can live on, you know? And we're at risk of losing a lot of the culture from First Nations people. So, um, I see, you know, this, this kind of agreement as some reparation, you know, making amends for things of the past and, um, you know, important, going back to what

• 3:15:12Simon Hill?

  we were talking about earlier, in just creating a societal, uh, perspective shift to, to one of guardianship and stewardship. And, uh, you know, the more we can integrate, uh, these First Nation cultures back into society, um, the better. So, uh, the reason I bring that up is that the, you're right, the profits of the book will be going. Uh, there are still parts of the Daintree that are privately owned and are, uh, under threat of deforestation. So Half Cut, the organisation, uh, led by a friend of mine actually, has half a beard.

• 3:15:49Rich Roll?

  Oh yeah, that guy. I know that guy. Yeah, yeah, yeah. What's his name?

• 3:15:53Simon Hill?

  Jimmy Halfcut.

• 3:15:55Rich Roll?

  Jimmy Halfcut.

• 3:15:56Simon Hill?

  Half a beard to represent half the world's forests.

• 3:15:59Rich Roll?

  He's in Goodfellas or something.

• 3:16:00Simon Hill?

  Yeah. So half the world's forests have been cleared and that's what his half beard represents.

• 3:16:06Rich Roll?

  Yeah, I never understood what the symbolic nature of that was.

• 3:16:10Simon Hill?

  So it's a, it's a conversation starter. Whenever I'm out with him, everyone of course comes up and says, hey dude, what's going on?

• 3:16:16Rich Roll?

  How long has he had half a beard?

• 3:16:17Simon Hill?

  Five years, I think. Yeah, a long time. He says he's going to regenerate it though. So he's, he's regenerating it as we regenerate.

• 3:16:25Rich Roll?

  I see.

• 3:16:27Simon Hill?

  So I hope that we see a day where he has a full beard. But he runs the organization Halfcut that is buying back some of the land around the Dantry, still part of the Dantry, that isn't under World Heritage, but buying it back and then having it listed under World Heritage and, you know, under the care of the indigenous people that are from that area.

• 3:16:52Rich Roll?

  You're a beautiful man, Simon Hill.

• 3:16:54Simon Hill?

  Thank you.

• 3:16:55Rich Roll?

  Come back anytime, man. We've got plenty more we could talk about.

• 3:16:57Simon Hill?

  Yeah, I hope, I hope I haven't confused people.

• 3:17:01Rich Roll?

  No, I think it's good. I think, I think you cut through a lot of confusion and created clarity from my perspective. More clarity again can be found in Simon's book, The Proof is in the Plants, plantproof.com. On Instagram, Simon is constantly sharing super helpful information, at plant underscore proof, right? And you're on Twitter a little bit. You mix it up. You're getting spats once in a while.

• 3:17:25Simon Hill?

  I'm an avid Twitter user. I don't have many followers on there.

• 3:17:30Rich Roll?

  It's good. It's a good time. I always check in like, you know, like, you're not afraid to scrap it up a little bit.

• 3:17:36Simon Hill?

  I thought, I wondered actually, does Rich watch this?

• 3:17:39Rich Roll?

  Oh yeah. Oh dude, I, I, I watch from the sidelines. I don't participate.

• 3:17:43Simon Hill?

  I have a standard copy and paste line, which is, can you, can you provide a study that supports this claim?

• 3:17:51Simon Hill?

  And I'll tell you what, my strike rate is not great. I get barely any replies to that one.

• 3:17:55Rich Roll?

  Right. That's the conversation ender.

• 3:17:58Simon Hill?

  Yeah.

• 3:17:59Rich Roll?

  There you go.

• 3:17:59Simon Hill?

  There are some people who, of course, can engage in, you know, a civil conversation, but...

• 3:18:06Rich Roll?

  Yeah, but three or four tweets and it generally devolves into less civil. But we kept it civil here today.

• 3:18:13Simon Hill?

  We did.

• 3:18:14Rich Roll?

  Be civil in the world and enjoy the rest of your time in LA and we'll do this again soon.

• 3:18:20Simon Hill?

  Rich, love you, brother. Thank you so much for having me.

• 3:18:23Rich Roll?

  And, and if you find yourself in Bondi, Bondi Beach, where Simon hails from, you gotta visit Eden, Simon's restaurant.

• 3:18:33Simon Hill?

  And I can't take the credit. I can't take all the credit for that. I need to...

• 3:18:36Rich Roll?

  Well, Tanya.

• 3:18:37Simon Hill?

  Tanya, my lovely partner, she, you know, she's made that the place that it is. So of course, if you're in town, come on down.

• 3:18:46Rich Roll?

  Yeah, for sure. Best plant-based eats in all of Sydney, right there in Bondi Beach. When, when I was spending time there, that was my second home. And, you know, next time you're gonna have to let me pay for a meal. Because Simon didn't let me pay for a single meal.

• 3:18:59Simon Hill?

  No, no, no. We loved having you. It was our treat.

• 3:19:02Rich Roll?

  It was great. So, thanks, man. Much love. Talk to you soon. Peace.

• 3:19:06Simon Hill?

  Plants.

• 3:19:15Rich Roll?

  That's it for today. Thank you for listening. I truly hope you enjoyed the conversation. To learn more about today's guests, including links and resources related to everything discussed today, visit the episode page at richroll.com where you can find the entire podcast archive, as well as podcast merch, my books, Finding Ultra, Voicing Change, and The Plant Power Way, as well as the Plant Power Meal Planner at meals.richroll.com.

• 3:19:46Rich Roll?

  If you'd like to support the podcast, the easiest and most impactful thing you can do is to subscribe to the show on Apple Podcasts, on Spotify, and on YouTube, and leave a review and/or comment. Supporting the sponsors who support the show is also important and appreciated. And sharing the show or your favorite episode with friends or on social media is, of course, awesome and very helpful. And finally, for podcast updates, special offers on books, the meal planner, and other subjects, please subscribe to our newsletter, which you can find on the footer of any page at richroll.com. Today's show was produced and engineered by Jason Camiolo, with additional audio engineering

• 3:20:29Rich Roll?

  by Cale Curtis. The video edition of the podcast was created by Blake Curtis, with assistance by our creative director, Dan Drake. Portraits by Davy Greenberg. Graphic and social media assets courtesy of Daniel Solis, Dan Drake, and A.J. Akpo Diatte. Thank you, Georgia Whaley, for copywriting and website management. And of course, our theme music was created by Tyler Pyatt, Trapper Pyatt, and Harry Mathis. Appreciate the love, love the support. See you back here soon. Peace. Plants.