Is your gut the secret to anti-aging? 6 science-backed ways to boost your bone strength, muscle, and balance | Prof Elaine Dennison

Picture the sound of a bone snapping - the kind of sound that makes you wince - and ask yourself how often you’ve thought about your bone health. Most of us only think about bone density when something breaks. Until then, your bones stay almost invisible, carrying you through every day. In today’s episode, Professor Elaine Dennison, a world-leading expert in bone health, explains why that needs to change, why stronger bones are key to living more healthy years, and why declining bone health isn’t inevitable. Elaine explains why it’s not just about avoiding broken bones, but about learning to understand one of the most important living tissues in your body. By the end of the episode, you’ll know exactly how to protect your bones so they can look after you now and for many years to come. Could your bones be the missing anti-aging link you’ve been missing? 🌱 Try our science-backed and tasty wholefood supplement Daily30 🌿Let your gut microbes snack on the ZOE Gut Health Bar Build healthy habits. Download the ZOE app today and start your trial for just £2.30 for your first week. 👉 Join ZOE Follow ZOE on Instagram. Timecodes 00:00 Intro 03:05 Are your bones dead tissue? The truth about bone biology 08:08 Peak bone mass: the age your bones stop getting stronger 11:06 What is osteoporosis? The condition you won't feel coming 14:01 Spinal fractures and death risk: what the research shows 15:53 What does osteoporosis do to your bones? The honeycomb explanation 17:46 Fragility fractures: why older adults break bones from a simple fall 20:02 Bone marrow function: what your bones do for your immune system 22:48 The gut-bone axis: how gut health affects bone health 27:01 Does stress affect bone health? The cortisol connection 29:45 Is alcohol good or bad for bone health? The surprising answer 30:16 Does extra weight protect your bones? What the science says 32:13 GLP-1 drugs and bone health: the risk no one's talking about 33:21 Muscle loss and bone density: why they're linked 35:37 DEXA scan: the only way to know your bone density 39:06 Osteoporosis medication: how doctors treat bone loss 40:51 Best exercise for bone density: why walking isn't enough 42:54 How much calcium do you need a day for strong bones? 44:04 Vitamin D and bone health: why you need it to absorb calcium 45:41 Why vitamin D deficiency is common in sunny Australia 47:22 Does HRT protect your bones? The benefits and risks explained 48:31 Do weighted vests improve bone density? What the evidence shows 49:44 How to improve bone health: the first steps to take 📚Books by our ZOE Scientists The Food For Life Cookbook Every Body Should Know This by Dr Federica Amati The Appetite Reset by Dr Federica Amati Food For Life by Prof. Tim Spector Ferment by Prof. Tim Spector Good Mood Food (preorder) by Prof. Tim Spector Free resources from ZOE The Smart Snacking Guide: How to feed your gut, fuel your day, and snack without guilt The Hormone Harmony Guide: Tuning Your Body’s Internal Orchestra Eating for Better Brain Health: Your brain-gut blueprint How to eat in 2026 - Discover ZOE’s 8 nutrition principles for long-term health Live Healthier: Top 10 Tips From ZOE Science & Nutrition Gut Guide - For a Healthier Microbiome in Weeks Better Breakfast Guide Mentioned in today's episode The effect of Daily30 on Gut Health, Energy Levels, and Hunger in Healthy Adults, Cambridge University Press (2026) Mortality Rate in Patients with Vertebral Compression Fractures, Geriatric orthopaedic surgery & rehabilitation (2023) The Influence of the Mediterranean Diet on Bone Health, Nutrients (2023) Have feedback or a topic you'd like us to cover? Let us know here. Episode transcripts are available here.

• 0:02Speaker 00

  Welcome to Zoe, Science and Nutrition, where world-leading scientists explain how their research can improve your health.

• 0:13Speaker 00

  It might surprise you, but your skeleton isn't just a rigid frame. It's one of the busiest organs in your body. Bone is actually a living tissue that constantly rebuilds itself, communicates with other organs and plays a vital role in immune health. It might not be as sexy as muscles, but bones are just as important. And whatever your age, there are things you can start doing today to help ensure that your bones support you for the long haul. Joining me today is Professor Elaine Dennison, rheumatologist and professor of Muscular Skeletal Epidemiology at the University of Southampton. She's a world-leading expert in bone health, why it goes wrong and how to protect it. Her research explores how our bones change throughout life

• 0:56Speaker 00

  and how best to protect our skeleton from childhood to old age. This episode isn't just about avoiding broken bones. It's about discovering one of the most remarkable and most overlooked living tissues in the human body. By the end of this episode, you'll think completely differently about your skeleton and you'll know exactly how to protect your bones so they can look after you.

• 1:19Speaker 00

  Elaine, is bone health only something that older women should worry about?

• 1:24Speaker 01

  No.

• 1:26Speaker 00

  Are my bones a non-living scaffolding, a bit like my fingernails, whose only job is to stop my body from collapsing into jelly?

• 1:34Speaker 01

  No.

• 1:36Speaker 00

  Can I tell that my bone health is declining without getting a scan?

• 1:40Speaker 01

  No, not normally.

• 1:42Speaker 00

  Do stronger muscles make stronger bones?

• 1:45Speaker 01

  Yes.

• 1:47Speaker 00

  To maintain good bone health, do you need to take expensive supplements?

• 1:51Speaker 01

  No.

• 1:52Speaker 00

  And finally, what's the biggest mistake that most people make about bone health?

• 1:57Speaker 01

  The one thing that I think is most important is not leaving things until later in life when you've got a problem because protection is always easier than cure, isn't it?

• 2:07Speaker 00

  You know, one of the things I'm struck by is on social media, there's an enormous amount of focus on building muscle, but you very rarely hear anything about bones. I was so confident that bones are just like my fingernails or my teeth, like really hard, but basically dead and that they were just sort of there. You know, they're like a coat hanger, you know, the stuff hangs off it. Otherwise, I would end up sort of like a puddle, like a slug. But what I'm hearing from you is I've got this all wrong?

• 2:35Speaker 01

  Bones do play an important protective role, so they do help protect internal organs, but they're definitely not a dead tissue. They're very much a living tissue. As we're sitting here, our bones are being constantly turned over. So bone is being broken down, bone is being formed. And in health, obviously, that's a balanced process. So the amount of bone that you break down, you replace. And it's a way of kind of the body's DIY. If you think of, if you've got a crack in a wall, you might want to put some polyfiller in to repair that. So your bones effectively should be doing the same thing. Where we get into problems is where that becomes unbalanced. So more bone is broken down than is formed.

• 3:20Speaker 01

  And then obviously you lose bone. So that is a problem. Beyond that, bones do more than just protect organs. You know, you've got cells, you've got bone marrow that's being active throughout your life. So you're making cells in your bones as well. It's a very, very active organ, but it's definitely a living thing. So there's absolutely a need to look after it.

• 3:44Speaker 00

  So I'm fascinated by this idea that I'm both breaking down my bones and rebuilding them.

• 3:48Speaker 01

  Yeah.

• 3:49Speaker 00

  I can see why it would make sense to rebuild them if they're broken. But why on earth would my body be like breaking down my bones? That seems really stupid.

• 3:59Speaker 01

  What would normally happen is that in a bone, you might get a tiny, tiny little crack or irregularity on the surface of the bone, like a micro fracture. And what your body can do is work out where the bones need either repairing or strengthening. So to do that, what it does is it sends some little cells in called osteoclasts that will make the area ready for repair. And then osteoblast will come in and do the repair. So it should be a balanced cycle where everything results in a sort of a net equal balance. But it is important because if you completely stop bone turnover

• 4:38Speaker 01

  and we've got drugs that would do that, then you can see little fractures appearing actually enlarged. So you can see that actually it's a very beneficial process to have bone turning over in this way.

• 4:52Speaker 00

  So I think what you're saying is just through normal wear and tear, I'm getting like tiny little fractures in my bone just from like presumably walking around and falling over and whatever I might do. And then my body is identifying that. Is that the osteoclasts that you said?

• 5:08Speaker 01

  There are other cells in the body that are sort of detecting what's going on as well. But what will happen is the osteoclast will come in. They'll break down a little bit of bone, prepare the area, and then the osteoblast will come in and fill in that gap.

• 5:22Speaker 00

  And when you say prepare the area, it sounds like my body identifies that there's this tiny little crack. And basically it breaks it down, like it's almost like there's a, you're, I'm thinking now, you know, there's a broken part of the wall. It's like ripping out some of those bricks. And then I'm going to hopefully put in some new bricks afterwards.

• 5:39Speaker 01

  Yes.

• 5:40Speaker 00

  And so that means it's not just like they're coming in and, and building. Actually, I'm, I'm having the, this part of my bone sort of pulled away.

• 5:48Speaker 01

  Yeah.

• 5:48Speaker 00

  And then something new put on top. So it's already massively dynamic compared to anything that I would have thought about. Which as I think about it, it's sort of obvious because I've seen my children grow up and clearly their bones, I guess, are getting longer because I've never noticed them just like falling out and new ones coming in. But I guess I had sort of assumed that when you're an adult, that was done. But this isn't true. This like repair and replacement is something that continues throughout adult life?

• 6:12Speaker 01

  Yeah, so repair and replacement continues throughout adult life. Obviously, it's a little bit different in children and young adults to when you've reached what we call skeletal maturity. So up to the age of about 30, then you're not only sort of balanced in terms of bone, you're actually growing bone, you're actually increasing bone mass. So when you talk about your children growing, obviously their skeleton gets larger. And then that skeleton gets stronger. So up to the age of 30, you've actually got this window when you're really building your skeleton. So it's a really, really important part of your life.

• 6:53Speaker 00

  That's really interesting. So you're saying that when you're fully grown and I'm thinking about, you know, my kids, that's often sometime between like 15 and 18. I would have thought them as being done because they're not getting any taller. But you're actually saying their bones are continuing to get stronger, which presumably also means heavier from that point?

• 7:12Speaker 01

  Yeah, so what we'd normally say is that you can, you can actually strengthen the skeleton up to the age of about 30. So up to the age of about 30, you're on a trajectory to something that we call peak bone mass. So that is the maximum amount of bone that you're ever going to have in your life. So the amount of bone that you can get by that point is really helpful. You peak at about 30 and then if you're lucky, you sort of, you stay along on the level for a while. But then sadly, in most people, there will be a decline. And it's particularly marked in women because as they go through menopause and they lose estrogen,

• 7:52Speaker 01

  then that is a catalyst or is normally a catalyst for sort of quite rapid bone loss.

• 7:58Speaker 00

  Why would your bones change as you go through menopause?

• 8:02Speaker 01

  So estrogen is a really, really important hormone for bone health. And it's important in men and in women. But you need to have enough estrogen on board really for, for bone health. It's very, very helpful. For women, obviously, most of that comes from sort of reproductive organs. So as they go through the menopause, they lose that benefit. You do still get some estrogen manufacturing in fat tissue, in adipose tissue. So there is a little bit of protection from there. But that loss of estrogen is quite a big hit for the bone because you get faster bone breakdown than bone formation. Everything becomes unbalanced, basically.

• 8:45Speaker 00

  Could you help us understand why like this change in estrogen is then changing like my bone health?

• 8:52Speaker 01

  Because it's affecting the balance. So what you would normally have in health is a balance between bone formation and bone breakdown. And you get an altered balance. So you get increased bone breakdown relative to bone formation. You've got two types of cells. You've got osteoblasts and osteoclasts. And the osteoclasts are the cells that come along and take a bite out of the bone. And the osteoblasts are the ones that come in and fill in the hole. That's what would happen. Commonly osteoporosis happens when, as I would say, the osteoclasts get greedy and the osteoblasts get lazy. So you get that imbalance and that's when you start to lose bone. And lots and lots of things can affect that balance.

• 9:37Speaker 01

  So lots of things can make that happen. But one of those things is estrogen withdrawal. So that's why for women. You know, the menopause is a particularly significant time and that's when a lot of women start to see problems with bone loss.

• 9:54Speaker 00

  And is it only women after menopause who have this shift where the the bone breakdown is getting higher than the bone creation or?

• 10:04Speaker 01

  No, I mean, men do suffer a little bit. I mean, osteoporosis is particularly common in women. But with men, you will see bone loss as well.

• 10:13Speaker 00

  And Elaine, what is osteoporosis?

• 10:15Speaker 01

  Osteoporosis is a loss of bone that makes you particularly vulnerable to fracture. So osteoporosis is a term that we use for lower than average bone density. But it's an asymptomatic condition. You wouldn't know unless you go on to actually break a bone. So it's the impact of having thin bones.

• 10:36Speaker 00

  And so you've talked about the risks for women after they go through menopause. Are there anybody else who should be worrying about this sort of increased risk of weaker bones?

• 10:47Speaker 01

  Yeah, I mean, it's not just women. All older people are at risk. So we do see osteoporosis in older men as well. There are groups of younger adults that we see osteoporosis in as well. So people who have to take steroid tablets for any reason, then they're at risk of osteoporosis. And normally their physician would be monitoring them. If someone has a history of anorexia, then often that has impacted their bone health. So they haven't reached their optimal peak bone mass or their potential. And then they tend to lose bone after that as well. People who have got gastro-intestinal problems, so someone's got inflammatory bowel disease

• 11:32Speaker 01

  or celiac disease or something like that, there's quite a long list of things that a doctor would look at and and it should trigger something that says, oh, I might need to investigate this.

• 11:45Speaker 00

  So someone's listening to this and saying, sure, that's sort of interesting. If you're a scientist and you're curious around like exactly what might be happening to your bones. But why should I care about the fact that, you know, I had peak bone health when I was thirty and now I've got less good bone health? Why does it matter? When I hit forty, I started feeling tired and sluggish. I remember thinking, great, this is it. It's all downhill from here. But I was completely wrong. It wasn't my age, it was my diet. It was literally sapping my energy. I was trying to juggle kids, work and exercise. And back then I'd just grab whatever food was nearby.

• 12:28Speaker 00

  I still have that crazy schedule, but what's changed is what I put in my body. Our own research at Zoe has shown that if your digestion feels off or you're regularly feeling exhausted, it's often because your gut bugs are starving. They thrive on a huge variety of plants, at least thirty different plants a week. And the more, the better. But if you're as stretched as me, it's not always easy to achieve this. And that's exactly why our scientists developed Daily Thirty. It's a great tasting gut health supplement with over thirty plants in every single scoop. I take it every day without fail. And because we're Zoe, we don't just guess, we test. We put Daily Thirty through a randomized controlled trial, the gold standard of testing.

• 13:09Speaker 00

  The results absolutely blew us away, proving it's good for energy, digestion and gut health. That trial helped us develop the formula that we have today. So if you're not feeling like yourself, don't settle for feeling sluggish. Head to Zoe dot com slash Daily Thirty and try it for yourself.

• 13:28Speaker 01

  But it matters because of the risk of fracture. So there's not a perfect correlation. You know, your bone density does not perfectly predict whether you'll have a broken bone or not. But there's a very strong relationship. So if you have thin bones, if you have osteoporosis, you are more likely to break something. And there are many, many different types of osteoporotic fractures. But a lot of people will know someone who's broken their hip or their wrist or a bone in their spine. As your bones get thinner, the chances of it happening go up. So that's why we'd encourage people to try and think about how they can protect their bones.

• 14:11Speaker 01

  Because no one wants to have one of those fractures.

• 14:14Speaker 00

  And Elaine, could you talk through like what the implications are of those fractures?

• 14:20Speaker 01

  Yeah, so the implications are different for different fractures. So if you break your wrist, it's going to be painful. It's probably going to have an impact on you short term, but you should recover. If you break a bone in your spine, if you have a vertebral fracture, there are quite a few studies that suggest you are more likely to die than someone who has not. But that may be in part because you have other underlying medical conditions that caused you to break that bone in the first place or that contributed to it. And that's what we're really seeing. The hip fracture can be a devastating event for people.

• 15:03Speaker 01

  There is a very significant risk of dying after a hip fracture, and that's quite early. So that's in the first sort of six months. So that can be typically more associated with direct complications of the fracture. So someone might develop pneumonia, they might develop a blood clot. There are the sort of immediate risks of having that fracture. And it is obviously a, you know, a really nasty fracture to have. It's very painful. And then obviously you have to have surgery, quite significant surgery. And then you need to get up and about again. It's broadly a rule of thirds. So if you have a hip fracture, a third of people sadly will die.

• 15:44Speaker 01

  A third of people will recover to some extent, but not necessarily to the level that they were before. And then a third of people will be able to return to previous levels of function.

• 15:58Speaker 00

  So that paints obviously a pretty devastating picture. I have two questions. Firstly, I'm interested because you talked about thinning of the bones. Could you help us understand a bit more? What does that actually mean? Does that mean literally that if I looked at the bone, it was, you know, it used to be five centimeters wide, two inches, and now it's half? And then why these very, you know, they're very specific injuries that you're talking about? Why is that?

• 16:22Speaker 01

  Yeah. So if I start with what happens to bone with age. So I mean, the best comparison is if people know crunchy bars, crunchy chocolate bars. If you were to cut a crunchy bar across the middle, or if you just bite into it, you've got the sort of the the chocolate shell around the outside. And then you've got the kind of the honeycomey bit in the middle. That honeycomey bit has got struts, you know, it's it's not a solid structure, is it? It's sort of almost like a lattice. So what happens in osteoporosis, if you look at it under the microscope, what you'd see is that those slats, that lattice just looks a little bit sort of ragged, a bit tatty. So some of the lattice is broken down.

• 17:07Speaker 01

  Some of it looks a bit narrower than it should do. It just looks like it's gone through the wars a little bit. And that structure isn't as strong. So the outer chocolate shell, if you like, would also be affected. But it's that lattice that we particularly see quite dramatic changes in. That's the trabecular bone.

• 17:29Speaker 00

  So that's what's happening as I'm losing bone density or to use your word osteoporosis is a way of saying that I've lost this lattice. I've got less bone and less good structure in there.

• 17:41Speaker 01

  Yep.

• 17:42Speaker 00

  How does this tie into those very specific?

• 17:45Speaker 01

  Fractures.

• 17:45Speaker 00

  Because I've got quite a lot of bones, haven't I?

• 17:47Speaker 01

  You have. And I picked those three because those are the three that researchers used to focus on. So we don't include the skull in that. But obviously you can break pretty much any bone through osteoporosis. It's just we don't have such good research in that because people are focused on those three. But we do know that if you count up some of those other fractures, that's a huge number. And it's got a huge impact in terms of healthcare systems.

• 18:17Speaker 00

  I feel like, I don't know any young person who has broken their hip. But I know more young people probably have hurt, like break things.

• 18:27Speaker 01

  Yeah.

• 18:28Speaker 00

  Probably than older people. So how does that happen when you're older? But it doesn't seem like it happens when you're younger.

• 18:33Speaker 01

  Yeah. Well, if you're young and you've broken something, it's probably because of trauma. So something's happened. You've had a car accident or you've come off a motorbike or you've fallen off something. As you get older, you need much, much less trauma to break something. So we talk about fragility fractures, fractures that occur from a fall of standing height or less. Some fractures just happen spontaneously, but normally it'd be a simple trip or a simple fall. And that would be enough in certain circumstances to lead to a fracture.

• 19:07Speaker 00

  And so if you have good bone health and you trip over from standing height, you don't expect to break the bone?

• 19:12Speaker 01

  That's the thing, you bounce, we say. I mean, you don't really bounce, do you? But you don't break anything.

• 19:17Speaker 00

  Is there anything also about like balance and reaction?

• 19:21Speaker 01

  Definitely.

• 19:22Speaker 00

  Speed fitting in here?

• 19:23Speaker 01

  Yeah, yeah. So if you can stop people falling over, then that's going to protect a significant number of people. The other thing I'd say is that if you look at the pattern of the sorts of fractures that people have over their life course, they tend to change a little bit. So it's more common to have a broken wrist in your fifties or sixties. Because if you fall, you tend to put your hand out to protect yourself. You tend to go forwards, do that instinctively, and you might break your wrist. But you tend to protect other things. As you get old, you seem to lose that protective reflex. So then you're much more likely to fall directly onto the hip.

• 20:06Speaker 01

  And at that point, you increase the risk of a of a hip fracture.

• 20:11Speaker 00

  If this episode has changed how you think about your bones, please share it. Most people don't think about bone health until it's too late and something breaks. You might change their life. We've talked a lot now about bones as breaking and in a way I feel like I'm in my comfort world of my bones being effectively sort of dead, even if they've been built or not. But I know if I come back to the quickfire questions, you were saying like, they do a lot and their role is not only as this sort of important scaffolding. How else are our bones contributing to our health?

• 20:45Speaker 01

  Within your bones, you have bone marrow, which is a factory for for blood cells and things like that. They're also involved in sort of what I would call body homeostasis. So the maintenance of levels of hormones and level of essential vitamins and minerals and things like that. So there are reservoirs for a lot of things. There is sort of a storage area for a lot of things that you will need.

• 21:11Speaker 00

  Can you give me an example?

• 21:13Speaker 01

  Yeah. So if you think of, I mean, calcium is the classic one, isn't it? So you know, the calcium, your calcium is stored pretty much in your bones. So you've got hormones that's released centrally that determine the right levels of these things in your blood.

• 21:29Speaker 00

  So my body is basically pulling calcium out of my bones to put it into my blood.

• 21:33Speaker 01

  Can do.

• 21:34Speaker 00

  I thought my calcium was only for my bones, but you're saying that other parts of my body need calcium as well?

• 21:39Speaker 01

  Yeah, you need calcium. Yes, you need it for many, many, many regulatory things. Yeah.

• 21:43Speaker 00

  So the bones are also like this reservoir of nutrients, but you also said something about the immune system?

• 21:50Speaker 01

  Yeah. So you've got, you've got a lot of immune cells sitting in the bone marrow. So what we know is that you need obviously a healthy immune system. You don't want your body to be in a state of chronic inflammation. So your body has to be ready to fight, but not constantly activated. I mean, you asked earlier about stress. You said, you know, is, is stress a bad thing? Well, stress might be a bad thing for your bones as well as for everything else, because it leads to your body just being sort of constantly on a state of edge of alert. And long term, that can be harmful for many things, including probably for your bones.

• 22:34Speaker 00

  Can you help me to understand this bone marrow thing? Like, I know that sometimes you don't see it very often, but you might get served like some meat that has the bone marrow in. Beyond that, I have absolutely no idea what it's for or why I care.

• 22:48Speaker 01

  You need certain cells in your blood for sort of basic functions to transfer oxygen to fight infections, to do things like that. So the bone marrow is where those cells are made. It's like a factory.

• 23:01Speaker 00

  What is actually being made in the bone marrow?

• 23:05Speaker 01

  All the blood cells, white blood cells, red blood cells, many, many different subtypes of that. But their role is to carry oxygen to fight infection, to remember when you've been exposed to infection before, so that you can mount another immune response to control inflammation. There are loads and loads and loads of cells.

• 23:25Speaker 00

  And all of these are made in my bones?

• 23:27Speaker 01

  In the bone marrow. The bone marrow is a really important part of that.

• 23:31Speaker 00

  So one of the things I've learned from hundreds of these podcasts now is that good gut health seems to be linked to like a remarkable number of different areas. But still, I was absolutely shocked to hear that there's a discussion about a gut bone axis. What is that?

• 23:50Speaker 01

  Yeah. So I mean, gut and bone are very closely linked. If someone's got gut pathology, if they've got problems with their gut, then that is a, a strong risk factor for osteoporosis, for thin bones, because they can't absorb what they need to. So a lot of the things that we've been talking about that are important for maintaining healthy bones are absorbed through, through the gut. So obviously you need good levels of that. Beyond that, obviously you've got a lot of bacteria in your gut. So those are important because they will help convert fibre to sort of short chain fatty acids. And that's important for inflammation.

• 24:31Speaker 01

  So we know that if you've got chronic low level inflammation, that's a bad thing. So that will tend to lead to poorer bone health. So the gut microbiome is important for maintaining good bone health.

• 24:50Speaker 00

  That's fascinating. So you're saying that if I have this low grade inflammation, which comes up so often on this podcast, it's something that's bad for us. This is actually in some way disrupting that pattern of like eroding away my bone and rebuilding it that I would have?

• 25:04Speaker 01

  You've got an imbalance, yeah.

• 25:06Speaker 00

  What tends to happen as a result of inflammation?

• 25:08Speaker 01

  So you tend to have more bone breakdown than bone formation. So you get that imbalance that we've been talking about.

• 25:14Speaker 00

  One of the things that I hear elsewhere around inflammation is that it's something that our body evolved for, for like a good reason. Like I'm running away from a lion and I need to do something. So do we have any understanding why inflammation would have any impact on this bone mechanism, which sounds from listening to it, so it's sort of slower than, you know, like pumping the cortisol into my, into my bloodstream?

• 25:39Speaker 01

  It's kind of a, a different thing. So, you know, if you're facing a lion or something like that, you absolutely need that acute response. You need that acute flight or fight response. So your cortisol levels will peak then. What you see in chronic inflammation is chronic low levels of slightly elevated cortisol. And cortisol is one of the hormones that's bad for bones. So that's what you're seeing.

• 26:05Speaker 00

  So raised level of this cortisol?

• 26:07Speaker 01

  Yeah, just a little bit, you know, not of the level that's really, really high. But yes, chronic low level is bad.

• 26:15Speaker 00

  Why is it that when your cortisol rates go up, do we know why that would lead our body to start to sort of strip away at the bones faster than otherwise?

• 26:25Speaker 01

  Cortisol has a huge number of effects and you want it in a sort of quite a tightly regulated level. If you have some profiles of a high level of a hormone, that can be a good thing. But if you've got chronically elevated levels, that's bad. So in osteoporosis treatment, if someone has osteoporosis, you might give them injections of PTH, tereparatide. So there are some injections that you can give where you're giving a spike of that drug. And that actually helps you build bones. It could be a really useful drug in treating

• 27:03Speaker 01

  osteoporosis. But if someone has got naturally high levels of the same hormone that are a little bit lower than those spikes but carry on all the time, that's bad for bone. So the way that a hormone is delivered, served to the body matters. It's a miracle more doesn't go wrong, really, to be honest. It's, it's very, very tightly regulated.

• 27:28Speaker 00

  It definitely sounds, I'm getting this picture of something very complicated where I've got this immense team of builders running around my body, breaking down all the bits that are damaged. And then somebody's got to come around like the next day and like fill it all. And potentially I have a situation where I've got sort of more of these builders tearing down my bone.

• 27:45Speaker 01

  Yeah.

• 27:45Speaker 00

  They're coming around to fix it. And so I can see that over time, it's getting worse and, and worse. I also get an appreciation of just how important these bones are. So I'd love to discuss a bit more, you know, what else might be harming my bone health. And so you've, you've talked about menopause, but are there any, you know, everyday habits, for example, that could be weakening our, our bones without us knowing?

• 28:09Speaker 01

  Yep. Smoking is bad for bones, definitely. Too much alcohol is bad for bones.

• 28:16Speaker 00

  Too much alcohol is bad for bones?

• 28:18Speaker 01

  Yes. Some alcohol is good for bones, interestingly. So alcohol has a very interesting relationship with bone health. So what you normally see is that the group of individuals who drink some alcohol, but well within recommended levels, have got better bone health than people who don't drink any alcohol at all. And definitely better than people drinking too much. So moderation is, is key.

• 28:45Speaker 00

  You're the first doctor I've managed to get on the show to tell me that drinking a little bit is good for me.

• 28:50Speaker 01

  Drinking a little bit is good. That's the good news. The other bit of good news, which goes contrary to most things, is that actually carrying a little bit of weight is good for bone as well.

• 29:00Speaker 00

  Elaine, we have to get you on the podcast more often. So not only should I be drinking, but if only I could get put on a bit more weight, that would be better.

• 29:06Speaker 01

  It's also good.

• 29:07Speaker 00

  Why is putting on more weight better for my bone health?

• 29:10Speaker 01

  Three reasons, actually. Firstly, if you do fall, you've probably got a bit of padding, I'm particularly thinking of your hips. Secondly, because estrogen is made in adipose tissue. And finally, if you've got a bit of weight, that's a bit more loading through the skeleton.

• 29:28Speaker 00

  What about caffeine?

• 29:30Speaker 01

  Having a huge amount of caffeine could be detrimental to your bones because it might affect the calcium balance. But in general, having a couple of coffees a day is probably okay. To be honest, you're probably better off drinking tea because there's been quite a lot of research saying that some tea drinking might actually be beneficial for bone. But if you're going to drink coffee, then you don't want to be having lots and lots and lots.

• 29:55Speaker 00

  Is it the caffeine in the coffee that's causing the problem?

• 29:57Speaker 01

  Probably.

• 29:59Speaker 00

  Now, you also talked about the psychological stress impacting bone health. Why is stress a risk factor?

• 30:07Speaker 01

  Again, probably because you've got that sort of that chronically raised cortisol level. You're probably also not sleeping so well if you're stressed. And there's some suggestion that actually that might affect your bone health. And then finally, because if you're very stressed, you're probably not doing the other lifestyle things that are helpful. Not eating what you might otherwise do. You might not be doing the other things that you might normally do.

• 30:37Speaker 00

  I also heard you talk about steroids earlier as something that could be harmful for my bone health. Are there any other sort of common medications where like I could have a side effect on my bone health?

• 30:50Speaker 01

  Um. There are lots of drugs that can do. Some of them are stronger than others. I guess the topical one are the DLP one drugs. That's an emerging area that's that's quite important. People have obviously benefited a lot from the medications if used in the right way with the right support. But you lose not just fat, but you also lose muscle. And muscle's very important for bone. So there's a lot of research at the moment trying to understand whether there might be a long term impact on fracture risk. And the reason we say that is because if you think of other parallels, you know, people have had surgery, you know, gastric

• 31:35Speaker 01

  banding or, you know, partial gastrostretism, things like that, their fracture risk, their risk of breaking, something typically goes up. So there's a lot of effort at the moment going into understanding whether we're going to see the same pattern with some of those drugs.

• 31:50Speaker 00

  Can you help us to understand that? Because at the moment, I'm not understanding the link between losing muscle and why that's having any impact on my bones?

• 31:58Speaker 01

  Because the muscles are really important for bones. So they sort of, again, there's a lot of crosstalk between muscles and bones. And bones are strengthened by having enough muscle around them. So what you would normally do is um link muscle and bone health. And if you lose muscle, then that will almost certainly have an impact on your bones as well. Even if it wasn't having a direct effect on bone density, and there probably is some kind of relationship, then um if you've lost a lot of muscle, that increases falls risk and things like that. So you're more vulnerable from that.

• 32:42Speaker 00

  I think it's another story about how you have to be very careful that when you're losing weight, that you're maintaining muscle.

• 32:49Speaker 01

  Yeah.

• 32:49Speaker 00

  We talked a lot about these actions that are maybe increasing the rate at which the bone has been pulled apart. But is there anything you can do to actually increase the pace at which the bone is getting rebuilt? And do these muscles fit in in any way?

• 33:05Speaker 01

  Exercise, resistance exercise is very powerful. There's a lot of muscle bone crosstalk, where a muscle will pull on a bone that will typically strengthen the bone. It will be different at different ages. But in general, if you've got good muscle mass, you will have better bone health as well because of the sort of that crosstalk.

• 33:32Speaker 00

  The analogy I'm thinking about is like with going to the gym.

• 33:35Speaker 01

  Yeah.

• 33:35Speaker 00

  You have to sort of hurt your muscles to make them then go stronger. And you're saying this is almost the analogy on my bones that the muscles are pulling on the bone as the bone is like, wow, I'm getting yanked really hard by these muscles. I need to make my bones stronger.

• 33:48Speaker 01

  Make it a bit stronger. Yeah.

• 33:49Speaker 00

  And so does that mean that, you know, if I sit on the sofa all day long, my bones will weaken, they won't try and rebuild them?

• 33:58Speaker 01

  Yeah, you need to be doing things.

• 34:00Speaker 00

  Action. That's really interesting. Now, before we move on to all the ways you can build healthier and better bones, I'd just like to ask, how can someone listening to this know if their bone health is declining?

• 34:14Speaker 01

  There's no way that you'd know unless you have a DEXA scan. Unless, if you've broken something, if you've already had a fracture, then in most healthcare settings, someone would have picked up on that and would have said, oh, we need to consider this. Let's start doing some tests to see whether you're vulnerable to another fracture. Now, that is a little bit more nuanced than I've just told you because there are computer tools that you can use through answering a load of questions that give you a good steer into whether you're likely to be at risk. So if someone went to a healthcare professional

• 34:59Speaker 01

  and said, I'm worried about my bones, they may well start by asking some of those questions because that gives a good idea of someone's risk. FRAX is the one that we often use, F R A X. You know, you can just Google FRAX and it'll it'll come up and ask you a load of questions. And if you've got your bone density results, then you can put that in, but it will give you a number. And that is probably the way that a lot of people are trying to manage demand on the services best they can.

• 35:36Speaker 00

  So I'd love to start talking about what you can do. And actually, I think this feels like the first place to start with. So if you're listening to this and you're worried about your bone health, what would be the things where you would say like, it's really important you go and see your doctor?

• 35:49Speaker 01

  Okay, yes. So if they haven't already brought it up with you, I think if you've got um a close family relative who's broken their hip or wrist or bone in their spine, if you've got certain medical conditions, so if you've got rheumatoid arthritis or a gut disease that stop you absorbing drugs properly, obviously, if you're on steroids, if you're a smoker, if you're a heavy drinker, there are a couple of things. Often, if people have some of these conditions, then it will have been flagged already and there may already have been discussions. But if they haven't, it's worth a conversation to just see whether

• 36:34Speaker 01

  actually it would be worth taking it further.

• 36:37Speaker 00

  And it sounds like if you do this DEXA scan, then you actually get a really clear reading of your bone health?

• 36:43Speaker 01

  You do. I mean, it's not a crystal ball. So what you get is a measurement of your bone density, which is one of the things, like I say, you can estimate someone's 10 year risk of breaking something without necessarily having that. So you do get information without it. If you have it, then it obviously gives more information that can be helpful and that gives you like a baseline. But that gives you an estimate of the chances of you breaking something. As I say, it's not an absolute. So some people will have really quite thin bone density and never break anything. And other people will have what at first

• 37:23Speaker 01

  sight looks better, but do break something. So there's a whole different discussion around bone quality and things like that. We don't really understand. But the DEXA scan is the really helpful thing in a lot of settings.

• 37:38Speaker 00

  And there are medications that doctors prescribe that can help with bone density?

• 37:43Speaker 01

  Yeah, there are several medications. Most of them are what we call anti-resorptive. So they stop bone breaking down. We have a few what we call anabolic bone forming drugs. In most settings, they are um slightly more restrictive in access for a whole variety of reasons. But most people probably go on what we call anti-resorptive drugs. So there are tablets, there are injections, and there are infusions that you can have bisphosphonates, other sort of the class of drugs. And they can be given as, you know, as a weekly tablet

• 38:23Speaker 01

  or as an infusion. We have other other drugs that we can use, you know. A lot of people will have heard of um a subcutaneous injection called denosumab that's given every six months. That's generally available. Um. Some people do get put on what we call bone forming or anabolic drugs. So PTH injections is one possibility. There's a new drug called romazosumab that became available in a lot of healthcare settings more recently, over the last sort of few years. And a lot of people are starting to use that. But different medications suit different people. And some people would be better suited to some forms of therapy than others.

• 39:08Speaker 00

  I'd love to talk about what people can do other than hope to get some magic drugs from their doctors. Could we start with exercise? Because you've been talking about this role of muscles. And I think most people listening to this show will be like, well, okay, I know that exercise is good for me. But I think they might be really surprised that it's really a big deal for their bones. I'll never forget the moment that everything shifted for me. I was at a public talk on nutrition. Listen to a speaker explain that my gut had trillions of microbes in it and that these bugs shaped every aspect of my health. That speaker was Professor Tim Spector, one of the world's top 100 scientists, who became my co-founder here at Zoe. Nine years later, Zoe runs the world's largest gut health research study. And the conclusion is simple.

• 39:54Speaker 00

  Gut health is health. How you feel, your long term health and your digestion are all shaped by the state of your gut. As a listener to this show, you know how important it is to feed your good gut bugs. But I suspect that like me, you have a busy schedule. And often you feel you haven't given them all the different plants they crave. And that's exactly why we created Daily 30. It's a gut health supplement packed with over 30 plants that you sprinkle onto any meal. It tastes great, adds a satisfying crunch, and gives your gut the diversity it craves. Finally, a healthy, happy, that's easy to stick to. I should know, I take it every day. And because we're Zoe, we don't just guess, we test. We put our original Daily 30 formula through a randomized controlled trial, the gold standard

• 40:39Speaker 00

  of testing. The results blew us away and proved it supports your digestion, energy and gut health. That trial helped us develop the formula we have today. Today, Daily 30 is a non-negotiable daily habit for me. So don't put your health off for the future. Go to zoe.com/daily30 and try it today.

• 40:59Speaker 01

  Yeah. Weight bearing exercise is good for bones. So what happens if you're engaging in weight bearing exercises, so you're effectively putting the weight of your skeleton through your skeleton? So that's a good thing. And really for it to be best for bone, what it has to be is repetitive loading that's a bit more than just walking. So that means jumping, step aerobics, running. There are exercises that you could obviously do in a gym setting. Resistance exercise generally is good. Or, you know, vigorous steps. So, you know, if anyone's ever done any kind of step

• 41:39Speaker 01

  classes like that, where you're literally going on and off a step. And swimming sadly, no benefit. Good exercise, but not for the bones, because the water's supporting your weight. If you're working with weights in a gym, it is important to be mindful if you've got any problems with your back. So if someone does have low bone density in their spine, we always say to them, be careful how you lift, because you don't want to put too much pressure on critical points in your spine.

• 42:08Speaker 00

  Can we move on to food? Are there any particular nutrients that people need to make sure they're getting in order to support their bones?

• 42:16Speaker 01

  Yeah, I mean, there are loads of things. So I mean, calcium's obviously the biggie. So you need to have enough calcium in the diet. But then you've got vitamin D, vitamin K, vitamin C, magnesium, all these things.

• 42:29Speaker 00

  And if I'm thinking about getting calcium from my bones, because I know there's also a whole debate about like how, whether you manage to absorb this properly. Is there any good scientific evidence around the sorts of foods that can in fact support my bone health and get that calcium into my bones?

• 42:48Speaker 01

  Dairy obviously is the classic for calcium. Milk, cheese, yogurt, things like that. Obviously, a lot of people don't consume a lot of dairy. So a lot of foods are fortified with calcium. Now, you're probably aiming for between eight hundred milligrams and a gram of calcium a day. You know, a lot of people read the backs of labels. So that gives you a sense of the sorts of amount. It does vary a little bit. So, you know, if you're still growing or you're pregnant, there are other conditions where you might actually need it even more than that. If you can aim for that sort of amount of calcium, you know, there are some vegetables that are rich in in calcium, things like that. But in general, dairy or fortified foods will be the source.

• 43:31Speaker 00

  And I understand that there is also calcium in plants. Is that right?

• 43:35Speaker 01

  Yeah, in some, yeah, in some green. There definitely is calcium there. But to get to that level is probably a bit more challenging.

• 43:44Speaker 00

  Is there any evidence about particular dietary patterns that are linked to sort of healthy bones and reducing the risks of the sort of, you know, fractures and everything that you were describing?

• 43:57Speaker 01

  Overall, I would say if you have a balanced diet, that's good. But the dietary pattern that has been probably most studied and most consistently associated with better bone health is the Mediterranean diet.

• 44:12Speaker 00

  You've mentioned vitamin D a number of times. I've definitely heard that vitamin D is good for you. But it sounds like it's got a specific link with bone health. Could you help us to understand that? And therefore, what's the advice to make sure that you're you're getting what you need?

• 44:28Speaker 01

  So vitamin D is important to help you absorb calcium. So vitamin D and calcium go closely together. So if you have very low levels of vitamin D, that is definitely a problem for your bone health, because your bones won't mineralise in the right way. A lot of people have heard of the term rickets. That's what happens if you don't have enough vitamin D. The bones just don't mineralise properly. There's a comparable thing in adults, but it's called osteomalacia. Obviously, it doesn't look quite the same. But again, it's very detrimental. It makes your bones really soft. So vitamin D is really important. You do get some from diet. A lot of it comes from sunlight. To get a really healthy dose

• 45:10Speaker 01

  of vitamin D, what you would do is, you know, have sort of exposed forearms, say, you know, on a sunny day for 20 minutes before you put sun cream on. Obviously, people are very nervous about a lot of sun exposure, because we know that there are risks in terms of skin cancer, things like that. But what we would often say is, if you time it carefully, 20 minutes, and then apply your high factor sun cream, that will give your body a huge vitamin D boost in summer. In winter, obviously, we're reliant on diet and the stores that we've built up. In Australia, where obviously there's a lot of sunshine, there's a very, very high

• 45:54Speaker 01

  prevalence of vitamin D and deficiency and deficiency, because people are very, very careful not to go out into the sun or to use sort of proper sunblock and things like that. So a little bit of do dishes sunshine is is a good thing for your bones.

• 46:09Speaker 00

  It's hard to get this stuff right, isn't it?

• 46:10Speaker 01

  It is. It is. There's a lot of conflicting advice.

• 46:13Speaker 00

  Moving on, you talked about what a big deal menopause is. If you take hormone replacement therapy and you're getting more estrogen, does that therefore protect you against this bone damage?

• 46:25Speaker 01

  Yeah. Yeah. So if you're taking HRT, then you don't have that bone loss that you would otherwise see. And you're protected for the duration of taking the HRT. Bone protection alone is not a good reason to make that decision about HRT or not. But it can feed into the conversation with a healthcare provider. If a woman goes through premature menopause up to the age of 50, then we're quite keen for people to consider taking HRT, because it's viewed almost as sort of like physiological replacement. So sometimes

• 47:07Speaker 01

  your body's lacking something, and medicine is able to replace that, to just put it back to where it should have been in health. So HRT up to the age of 50 is viewed more like that. But beyond 50, then the HRT guidance goes more into why are you thinking about doing this? What are the reasons?

• 47:29Speaker 00

  Why aren't you more pro HRT? I feel there's definitely been a big shift in terms of the general attitude towards HRT, probably more advanced in the UK than some other countries like the US, but it's definitely shifting in that way. And so I'm just sort of struck that you're saying it's got all of these benefits for bone health, and then you're sounding very cautious about it. And I'm just curious, where is that coming from?

• 47:55Speaker 01

  Because if you take it for more than five years, you see this slightly increased risk of breast cancer, which is why bone alone would not be enough. It's a small increased risk, because there's a background risk in everyone, even if they've never so much as looked at HRT. But it does go up if you take HRT longer term. The reason why we don't use it for just bone is because we have other agents that will protect your bone that aren't linked to any increased risk of cancer. If someone's taking it because actually it really improves their quality of life, well, fantastic. But just taking it to protect your bones isn't a good idea.

• 48:38Speaker 00

  Got it. I think we've talked a lot about exercise and diet and how vitamin D fits in and things like this. But I've also seen a bunch of gadgets that are supposed to support bone health. The first one is weighted vests. Should everybody be wearing a weighted vest who's trying to make sure they keep up their bone health?

• 48:57Speaker 01

  I think there is an emerging evidence base that suggests they may be helpful. So I think we probably will still see more people using them. Just to be clear, just sitting on the sofa with a weighted vest isn't going to do it. You have to be walking around.

• 49:16Speaker 00

  All right. So weighted vests, surprisingly positive, Elaine. What about whole body vibration plates?

• 49:23Speaker 01

  They've been around for longer, I would say. I think it probably a little bit more nuanced. I wouldn't say there's no place for them. So if you've got someone who can't do a lot of other exercise, there may well be a place, because they will help with muscle and balance as well as bone. But you wouldn't see as significant benefit for bone as some of the other things, to be honest. But in the right population, absolutely.

• 49:52Speaker 00

  So final question. If someone listening to this podcast has said, you know, I'm, I am worried about my bone health, I want to go and take some action. What would be the first thing that you would advise them to do?

• 50:07Speaker 01

  Work out what your calcium intake is, and check that that's sitting within the level that it should be. Think about whether your vitamin D levels are likely to be adequate. And if they're not, think about how you could safely. Raise that, activity weight bearing exercise, that's really important in all of this. Don't smoke, eat a balanced diet, just get enough of of everything, enough fruit, enough veg, enough calcium, enough protein.

• 50:37Speaker 00

  Amazing. Elaine, I really enjoyed that. We covered a lot of stuff. I'm going to try and do a summary and please correct me if I get any of this wrong. So the first thing I was struck by is our bones are alive and they're doing all these dynamic things, including this amazing impact on my immune system. We need to worry about them because we get to this peak bone health when we're thirty and then, you know, we might keep at that level for a while, but it's going to decline, you know, whether we're men or women. And for a lot of us, you know, living our modern Western lifestyle, we can be in a situation where actually it's been taken away faster than it's been replaced. And this is the osteoporosis that you were

• 51:20Speaker 00

  talking about, leaving you with sort of less bone than ideally you would have and therefore vulnerable to fractures. So unless you've had a scan or you do this questionnaire, this frax questionnaire, you won't have any idea until you have a fragility fracture, which sounds really bad, which is you fall over from standing height and something breaks, like your wrist or your hip. And one of the reasons it's a big deal is that we all end up both becoming, you know, our bones more fragile and our ability to balance is worse. Particularly common if you're a woman, because once you go through menopause, then your estrogen falls. And then that means that suddenly, for reasons that seem like a bit of a mystery,

• 52:02Speaker 00

  your body decides to break down your bone faster than it replaces it. We actually now understand there's some interaction between our microbes in our bones. And, you know, I've heard about the gut-brain axis, but now we have this gut-bone axis. If you have chronic inflammation, you have this raised cortisol and it's going to lower again the pace at which you're replacing the bones versus where it's coming out. And then we talked about lots of specific advice, which I love. One is lots of alcohol is bad for bone health, but a little is good. So I finally found a doctor who's telling me that drinking from time to time is okay. And interestingly, a bit of weight is also good for bone health, partly literally it's padding if I fall over, partly that actually I'm getting some estrogen

• 52:46Speaker 00

  from this fat. But interestingly also, carrying weight is really important because actually that's loading the bone and actually making it, you know, switch on this building process. So there's some benefit there. We talked about GLP-1, and I think what you said is although the data isn't really there yet, you think there's likely to be like a big risk there because of the impact on muscle. So if you're on GLP-1, you really need to think very hard about how that's going to impact your bones. And then in terms of, okay, so what can you do positively instead of these negative things? Like the number one thing I heard is weight bearing exercise. It's great to do some cardiac things and

• 53:26Speaker 00

  some swimming, but here you need to do something like a step class or resistance exercise, something where you've got real weight and you're sort of pounding your bones. And although that sounds like a terrible thing to do as you get older, you're actually saying, you know, perversely, a bit like exercise, it's really good for you, even though it might feel tiring at the time.

• 53:45Speaker 01

  Yes, you have to watch your joints. That's the only downside because your joints can suffer a bit, but yes.

• 53:52Speaker 00

  Then we talked specifically around food and what you said is the number one nutrient for my bones is calcium. We've all heard that. Interestingly, the Mediterranean diet is the diet pattern which is most associated with healthy bones. But critically, actually, it's vitamin D is the more important thing. You actually said, try and get twenty minutes of sun exposure on your arms before applying sunscreen, because actually the the power of that vitamin D is so beneficial for your bones. And finally, we talked about HRT and what you said is that is protective on bone loss, but you would not be suggesting it to somebody only for bone health because there are other medication that is just for bone health. So it's a sort of added bonus as part of the package when you discuss with

• 54:37Speaker 00

  your doctor about why it can be helpful.

• 54:40Speaker 01

  Perfect.

• 55:02Speaker 00

  I'll leave you with one final thought. What if there was one simple habit that when repeated could change how you feel for the better? I'd like to tell you about something that I do daily for my own health. It's called Daily 30, the gut supplement developed by our scientists here at Zoe. Daily 30 is made of over thirty hand-picked plants, including seaweed, fungi and different types of fibre. It's a source of plant protein, omega three and vital minerals. You simply add a scoop to any meal once a day to support your health and increase the plant diversity in your diet. And unlike synthetic supplements, Daily 30 actually tastes great. It's designed to be enjoyed because when a habit brings you

• 55:44Speaker 00

  joy, you're far more likely to stick with it. So next time you feel like your plate is missing extra plants, do yourself a favour, try Daily 30. It's a delicious and healthy habit that you'll feel good about and one that your gut will definitely thank you for. By the way, whenever we talk about Daily 30 as a good source of fibre, we're required to say that it contains four grams of tuttle fat per serving. Obviously, that's all amazing healthy fats from plants. So order yours today at zoe.com/daily30. See you next time.