Pod Insights The Diary Of A CEO with Steven Bartlett Most Replayed Moment: Mouthwash REVERSES The Benefits Of Exercise! Dr Nathan Bryan About this episode Dr Nathan Bryan is a leading nitric oxide researcher and biochemist, known for his work on cardiovascular health, blood pressure, and human physiology.
In this moment, he reveals a surprising and controversial insight: everyday oral health habits like mouthwash and toothpaste may be disrupting your oral microbiome and blocking nitric oxide production. He explains how this directly impacts blood pressure, circulation, and even reverses the benefits of exercise - unpacking the science behind one of the most overlooked systems in human health.
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Transcript Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.
0:04 Steven Bartlett? If I've just listened to everything you've just said there, and I want to improve my oral microbiome, what should I be doing?
0:10 Speaker 01 Well, I think the most important thing we've learned is what you shouldn't be doing.
0:13 Steven Bartlett? Yeah.
0:13 Speaker 01 Right? So it's not what should we do, it's what we shouldn't be doing. Number one, we have to get rid of fluoride. You know, just this past weekend, I was speaking at a dental conference in Salt Lake City, and there were people there from the National Toxicology Program, which in the US is the organization tasked with, if there's any kind of risk of exposure of a environmental toxicant, they're charged with doing the toxicology studies to see if there's an increased risk. What is the risk? And is there a safe level that is without risk? And what they report is that fluoride, there's no benefit of fluoride, and it's all risk. It lowers IQ in kids by as much as seven points. And it shuts down your thyroid function. And it's a neurotoxin.
0:57 Speaker 01 And as I mentioned before, most toothpaste has fluoride in it. And if you read the back of your toothpaste, it will tell you, at least in the US, I don't know about in other countries, but it says, "If you swallow this, call poison control." Because it's a poison. They're putting poison in toothpaste. And then if you also pay attention, it says, "Only put a pea-sized amount of toothpaste on your toothbrush." A pea size. But everybody that I know fills the entire bristle of the toothpaste with toothbrush with toothpaste. So that's about 10 or 15, sometimes 20 pea-sized amounts of toothpaste. And a pea-sized amount of toothpaste contains about half a milligram of fluoride.
1:39 Speaker 01 Now, if you're using 10, 20 times more than that pea size, now you're exposed to 5 milligrams, 10 milligrams of fluoride. And you don't even have to swallow it. This is a very small molecule, a molecular weight of 19. So it's absorbed directly across the buccal mucosa, the oral cavity, and it becomes systemic.
1:58 Steven Bartlett? I'm not going to use it anymore.
1:59 Speaker 01 No, you shouldn't.
2:00 Steven Bartlett? What should I use instead?
2:02 Speaker 01 You have to use a non-fornated toothpaste.
2:04 Steven Bartlett? And what about things like tongue scrapers?
2:07 Speaker 01 Now, tongue scrapers, the data, again, that's time-tested. That's an ancient practice. And even in our study, we found that people who do tongue scraping... Have a more diverse oral microbiome and they seem to have better oral health.
2:20 Steven Bartlett? Why is this? My girlfriend's been banging on to me. She's always bloody right. My girlfriend's been banging on to me about tongue scraping for the last two years. And I've kind of just ignored her. I've just kind of, yeah, babe, sure. And when she's not in the bathroom, I'm not using her tongue scraper. Cause it just looks strange. And for me, based on what I knew about the oral microbiome and the microbiome generally, I'm like, should I be scraping off all my bacteria?
2:44 Speaker 01 Well, if you're going to plant a garden, do you plant a garden on untilled soil?
2:49 Steven Bartlett? Listen, I know nothing about gardening. I'm asking the wrong guy. So maybe, yes.
2:52 Speaker 01 I grow my own food. So you have to till the soil, right? You gotta break up the soil so the seeds actually can be aerated. And you break up that biofilm. Yeah, you take the back of the dorsal tongue, I mean, almost to the point of the gag reflex, and you just pull that ideally copper tongue scraper forward. And you're going to see this goop.
3:14 Steven Bartlett? Yeah.
3:14 Speaker 01 Coming in there, but it's like, it's kind of like tilling the soil and it's increasing the diversity of the dorsal part of the tongue, the microbiome.
3:21 Steven Bartlett? So my girlfriend was right.
3:23 Speaker 01 In that regard, yes. But what we found was in that one kid, we saw the greatest increase in blood pressure. If you tongue scrape and use antiseptic mouthwash, that's the absolute worst scenario.
3:36 Steven Bartlett? Interesting. So if you.
3:38 Speaker 01 Think about this, you're tongue scraping, you're opening up the pores. And now you're using mouthwash, it's better to easily penetrate deep in the crips of the tongue and more effectively kill the bacteria.
3:48 Steven Bartlett? So you want to tongue scrape and then use a toothbrush without fluoride toothpaste?
3:53 Speaker 01 Absolutely. And no mouth, no, no antiseptic mouth rinse.
3:57 Steven Bartlett? Okay. And what about going to dental hygienists and things like that? Do you think that's an advisable idea? Cause once every quarter or so, I'll go and see a dental hygienist just to get everything sort of cleaned out.
4:08 Speaker 01 No, I think that's a good proactive practice, but you know, because you need to look at the the health of the gum tissue and the gingival tissue. And a routine clean and scraping the plaque off the teeth and allow, making sure you have good mineralization of the enamel of the tooth is good, but never let them do a fluoride rinse on you.
4:30 Steven Bartlett? Is there anything else on this subject of the oral microbiome and its relationship with nitric oxide that I need to be aware of before we move on?
4:36 Speaker 01 Yeah, there's also data showing that if you use mouthwash, you lose the cardio protective benefits of exercise.
4:43 Speaker 01 So think about this, we know that diet and exercise is the best medicine. And many people aspire to do that. They go and they try to eat good. They avoid the temptations of sugars and sweets. They exercise every day to try to increase their longevity and cardiovascular health. If you do that, and you're using mouthwash, you no longer get the benefits from exercise. And we've already established, you don't get the nitric oxide benefits from diet. So two out of three Americans wake up every morning and use mouthwash. And two out of three Americans have an unsafe elevation in blood pressure.
5:18 Steven Bartlett? What's the mechanism there?
5:20 Speaker 01 Well, because you're killing the the oromicrobiome that's partly responsible for production of nitric oxide. Without nitric oxide, you get constriction of blood vessels, and it leads to high blood pressure.
5:31 Steven Bartlett? That's crazy. And is there a link between our hormone levels, things like my testosterone levels, and the nitric oxide?
5:39 Speaker 01 Yeah, so this is a two way street. So in men, testosterone activates nitric oxide production. In women, estrogen activates and stimulates nitric oxide production. So as long as we have optimal sex hormones, and as long as the enzyme in the lining of the blood vessel can functionally produce nitric oxide, that explains the cardio protective benefits of hormone replacement therapy.
6:01 Steven Bartlett? Got you. So taking testosterone or estrogen therapies helps to increase my nitric oxide levels?
6:08 Speaker 01 As long as the enzyme is functional and coupled, which means that we have to we have to understand the enzymology and the biochemistry of that reaction to where when it's exposed to testosterone, the cell can actually make nitric oxide in response.
6:22 Steven Bartlett? And there's a two way relationship as well with exercise then, because I've read in your book that exercise activates and stimulates nitric oxide production. But you also just told me that if you want to get the great benefits of exercise, you need nitric oxide in the first place, because else your blood cells are going to be very narrow, less oxygen traveling through you. You're going to do a worse workout as well, presumably.
6:44 Speaker 01 Well, think about, I mean, there's other agonists too, like vitamin D. I mean, most Americans are deficient in vitamin D. People with low testosterone have erectile dysfunction. And why is that? Because they're not stimulating nitric oxide production, and they're not dilating the blood vessels, so they develop ED. So all of this, no matter what it is, which is related to vitamin D deficiency, which is activating or stimulating nitric oxide, if it's low hormones, if it's a poor diet, sedentary lifestyle, all of that can be explained by insufficient nitric oxide production.
7:12 Steven Bartlett? When I think about the role that food plays in my nitric oxide production, what should I be eating to increase my nitric oxide levels, or to keep them at a healthy level?
7:25 Speaker 01 I think the same answer is for that, too. It's not so much what we should be eating, it's what we should not be eating.
7:33 Steven Bartlett? Okay.
7:33 Speaker 01 So we'll cover those step by step. Number one, you have to avoid sugar and high glycemic index foods. Because sugar is a toxin, it's a poison. And let's think about what sugar is. So when we eat sugar or drink sugar beverages, right, whether it's sucrose, whether it's fructose, whether it's high fructose corn strip, the end result inside the human is we see an increase in glucose. So elevation in blood sugar, or blood glucose, is diabetes, right? And now there's continuous glucose monitors that you can get anywhere. And everybody does this. So if you eat something and it causes an increase in your blood sugar, blood
8:14 Speaker 01 glucose, then you should avoid that. Because glucose, as the name applies, is glue, right? It's sticky. And if we, if you have a soda and you spill it on your countertop, you come back the next day, it's sticky, right? That's what happens inside the body. That sugar sticks to everything. It sticks to proteins, it sticks to enzymes. It binds to hemoglobin. And sugar stuck to hemoglobin is what we call hemoglobin A1C. And what is that? It's a, it's a marker of long-term glucose control. If you have hemoglobin A1C of greater than 5.7, you're diabetic.
8:49 Speaker 01 So it's not just hemoglobin it sticks to, it sticks to the enzyme that makes nitric oxide. And in biochemistry and enzymology, enzymes have to be able to undergo conformational changes, right? So it transfers electrons from one donor to an acceptor and that's how biochemistry is done. But if sugar is stuck to that enzyme, it locks it in some conformation and it can't do its job. It can't make nitric oxide. So sugar is an absolute poison and it kills many enzymes and binds to everything.
9:21 Steven Bartlett? And it lowers nitric oxide production?
9:23 Speaker 01 Absolutely. That's why diabetics have a 10x higher incidence of heart attacks, stroke, all-cause mortality. That's why they develop neurological or peripheral neuropathy. That's why they have non-healing wounds. There's no nitric oxide. That's why they're developing diabetic retinopathy, macular degeneration, pancreatitis. I mean, all of that can be traced back to a lack of nitric oxide production because the sugar's stuck to the enzyme. The sugar destroys the oral microbiome and completely changes the ecology of the bacteria and completely shuts down nitric oxide production.
10:00 Steven Bartlett? Just a bit of a tangent there. You mentioned that's why they have open wounds that don't heal.
10:04 Speaker 01 Yeah, diabetic ulcers.
10:05 Steven Bartlett? Okay, so nitric oxide's playing a role, a healing role in wounds and scars?
10:11 Speaker 01 Absolutely.
10:11 Steven Bartlett? So I've got this scar on my head. I was playing football the other day. Someone ran into the back of my head and they like, they passed out and got taken away by an ambulance, but I was just left with this big like scar on the back of my head, which I've had like glue stitched. So I'm wondering, I'm like, if I...
10:27 Speaker 01 Apply the nitric oxide serum. It'll stimulate blood flow to that. It'll improve cellular turnover and heal that wound and basically remediate the scar.
10:35 Steven Bartlett? And how do I do that? Is it...
10:37 Speaker 01 Yeah, so you take one pump from each side.
10:39 Steven Bartlett? So one pump from this side.
10:40 Speaker 01 And turn it around, one pump from the other.
10:42 Steven Bartlett? Yeah.
10:43 Speaker 01 And now if you apply that and mix it together, as soon as you mix it together, it starts to generate nitric oxide gas. So then that gas will diffuse into that tissue. It's going to increase blood flow and it's going to mobilize stem cells and it's going to improve cellular turnover and completely remodel that and heal that. And if it were an infection in there, it would kill the infectious bacteria.
11:04 Steven Bartlett? Okay, well, we shall.
11:07 Speaker 01 Second one.
11:07 Steven Bartlett? We shall see if that works. So back on this point of food then, so sugar's bad.
11:12 Speaker 01 Sugar's bad, yeah, you gotta eliminate sugar. And I think the benefits of it, like a straight ketogenic diet or a straight, you know, vegan vegetarian diet is just the elimination of sugar and carbs.
11:21 Steven Bartlett? Yeah.
11:22 Speaker 01 Right? But I think, to answer your question, what should we be eating? I think you've got to eat a balanced diet in moderation. You know, Americans are overfed. All you gotta do is walk around and see the epidemic of obesity. Good, high-quality protein, good-quality fats, and little or no carbs. And it's really that simple.
11:43 Steven Bartlett? And why did you write a book about beetroot?
11:46 Speaker 01 Beets, yeah, the beets hit the, uh, really the airwaves back in 2012 in the London Olympic Games. Uh, there was a lot of data coming out at the time of the benefits of beetroot juice on enhancing athletic performance. And there was a benefit of the nitric oxide being produced that could explain the improvement in athletic performance. The problem is, these athletes were drinking liters and liters of beetroot juice and causing a lot of gastric discomfort, causing diarrhea. Their urine and their feces would turn red, and a lot of people interpreted, misinterpreted that as gastric bleeds or urinary bleeds. And then when I started looking at the products on the market, most of the beet products, the desiccated beet powders, provided zero nitric oxide benefit.
12:31 Speaker 01 They didn't contain any nitrate, no nitrite, they were just, we called them dead beets. They're, they're dead beet products. And so I thought, if people, if consumers are out there looking for beets because they've been shown to enhance their performance, but that enhancement in performance was dependent upon the beet's ability to improve nitric oxide production in the body, then the non-scientist out there wouldn't know what to look for. Right? They're buying products that aren't providing any benefit to them. And so years ago, we would do randomized placebo-controlled clinical trials, and we would take some of these commercial beet products that you can go to your local nutrition store or pharmacy, buy off the shelf, and we would use those as placebos
13:14 Speaker 01 in our clinical trials, because it's the perfect placebo. So what I tried to do in that book is educate, okay, what is it about beets that are so important? What's the mechanism and what is necessary in those beets that can improve nitric oxide production? So again, everything I do is intended to educate and inform the consumer so that they know how to make informed, educated choices on the products they're taking, or the foods they're eating, or their oral hygienic practices.
13:47 Steven Bartlett? I'm trying to find the page in your book, but there was a page in your book where you describe beetroot as the most underappreciated food in the history of eating.
13:59 Speaker 01 Yeah, that may be in the Beat the Odds.
14:01 Steven Bartlett? I thought it was in this book.
14:02 Speaker 01 But if you go back to historical times and you look at the hieroglyphics on caves of the ancient cavemen, you know, people thought they were drinking wine because they would have these red stuff in this before battle. But what these ancient Egyptians were doing was they were drinking beet juice to improve their performance before they went into battle, so that they were ready, they were energized, they improved their circulation. So that's the historical study on beets. And obviously, these were beets grown at a time when there were no herbicides, pesticides, and the soil was probably fertile, so these beets were full of nutrients, probably full of nitrate that provided the benefits of that.
14:43 Speaker 01 But unfortunately, today, the beets that are grown, at least in America, really are nutrient depleted, just like most of the food.
14:50 Steven Bartlett? So would you recommend people eat beetroot?
14:54 Speaker 01 No, because as would, again, through our survey that we published in 2015, we realized that you really can't eat enough beets to get enough nitrate to improve your performance. And the other caveat is that if you're using mouthwash, you've got fluoride in your toothpaste or fluoride in your drinking water that you're mixing the beet powder in, you're not going to get a nitric oxide benefit from it.
15:12 Steven Bartlett? There's a graph in front of me here, which I printed off, which shows the rise in antacid medications.
15:18 Speaker 01 Oh yeah, from 2004 to 20, so a 20-year period, we're seeing, what is that, almost a quadrupling of the use of antacids. And this is globally, or is this in the US? That's worldwide, I believe. Yeah, worldwide. Now, this is a problem. I mean, these, these antacids. What is an antacid? So it's a medication that's given orally to suppress stomach acid production. Yeah. And as a biochemist and physiologist, I can't think of nothing more damaging than to inhibit stomach acid production. Because stomach acid is required to break down proteins into amino acids, whether it's you're eating animal protein or, or plant-based protein.
16:01 Speaker 01 It's required for nutrient absorption. You need stomach acid to absorb B vitamins. You need stomach acid to absorb selenium, chromium, iodine, magnesium, iron. I mean, most nutrients, micronutrients are absorbed in the lumen of the stomach. And if the stomach can, is not making stomach acid, then these nutrients are not absorbed. And most Americans, 75% of Americans are deficient in magnesium. 95% of Americans are deficient in iodine. I mean, it's a huge problem. These are the brands like Gaviscon? No, these are like the, the Prilosec, the Prevacids, the Nexium, the prescription medications, or Omeprazole, Pantoprazole. These, today, in the US, I think it's probably
16:46 Speaker 01 worldwide, you don't even need a prescription for these from your physician. You can go to your local drugstore and you can buy these, what we call proton pump inhibitors, or PPIs. What about Tums? Over the counter. So there's a difference in, so Tums and things like baking soda are a buffer, right? Sodium bicarb or calcium carbonate. And it's a buffer, right? So if you, if you have an acute bout of hyper secretion of acid, you can take a Tums or some buffer, some base, alkaline substance, to neutralize the acid. Neutralizing acid is completely different than inhibiting its natural production in the paloric cells of the stomach. So what is the difference between, have you heard of Gaviscon before? Yes.
17:31 Steven Bartlett? Yeah. What's the difference between like a Gaviscon?
17:34 Speaker 01 Well, there's, there's certain classes of antacids. There's what we call H2 blockers. There's proton pump inhibitors, and then there's the natural buffers that are just kind of neutralizing the acid environment in the stomach. Gaviscon, I'm trying to think what class that falls under. I don't think it's widely used here in the US. I mean, the main drugs used here are Prologin, Nexium, Prevacid. Those are the over the counter. And then the main prescription medications are the Omeprazole and the Pentoprazole.
18:00 Steven Bartlett? Gaviscon is a commonly used antacid brand, and the active ingredients are aluminium hydroxide and magnesium carbonate?
18:10 Speaker 01 Oh, so Gaviscon. So number one, it's got aluminium in it, which you should, should absolutely be avoided. But yeah, that just, it looks like a buffer. It's got an hydroxide, aluminium hydroxide, which is a strong base. So it's neutralizing the stomach acid production. But it's, it's a neutralizing agent, but anything that contains aluminium, you should absolutely avoid.
18:29 Steven Bartlett? And my, I said, I've mentioned her a few times today, but my girlfriend's a breath practitioner. She runs a business called barleybreathwork.com, hashtag ad. And one of the things she's talked to me a lot about is mouth breathing. And I know there's a relationship between nitric oxide and how we choose to breathe, whether it's through our nose or through our mouths. Can you explain to me that, that link?
18:51 Speaker 01 You know, when we talk about the enzyme that's found in the lining of the blood vessels, when we started this segment, that same enzyme is found in our epithelial cells, in our upper airways, in our sinuses. So just like exercise can activate nitric oxide production in the lining of the blood vessels, deep breathing, nasal breathing activates that enzyme in the epithelial cells of our sinuses. And so when we do nasal breathing, it's activating the enzyme to make nitric oxide. And now we're delivering that nitric oxide gas into the bronchioles, the lower airway. It's dilating those bronchioles. Moreover, it's dilating the pulmonary arteries. So now we're improving oxygen uptake, oxygen delivery, and that's why nasal breathing and deep breathing has been shown to lower blood pressure.
19:35 Steven Bartlett? This is a pretty crazy graph I took from Google as well, which shows just how interested people are now getting in the subject of mouth breathing.
19:42 Speaker 01 Oh, yeah. Again, going over the past 20 years.
19:47 Speaker 01 Yeah, no, I think there's a lot of people, I mean, obviously, your girlfriend, there's a Patrick McEwen, McEwen in the UK.
19:53 Steven Bartlett? Came into Dragon's Den, I did a, made him an offer in Dragon's Den.
19:57 Speaker 01 Yeah.
19:58 Steven Bartlett? Yeah.
19:58 Speaker 01 No, I think that the benefits of that are pretty well, and mechanistically, we understand the benefits of it. So the mouth breathers are not only bypassing this natural nitric oxide production pathway, but when you mouth breathe, it completely changes the microbiome.
20:15 Speaker 01 And so you're not only bypassing the nitric oxide producing in the upper airway, but you're inhibiting nitric oxide production in the mouth from the microbiome. Because you're fully oxygenating the mouth, it's changing the pH of the saliva, and completely changes the microbiome, and completely shuts down nitric oxide production.
20:33 Steven Bartlett? Interesting, interesting.
20:36 Speaker 01 So you have to, I mean, I'm a big fan of mouth taping. But for me, I know, and I watch my kids, but sometimes there's anatomical issues where there's obstructive airways and airway obstruction that has to be corrected by dental appliances or some, sometimes surgery. But the worst thing you can do is tape your mouth and your airway be constricted and, you know, suffocate. So before you do mouth taping, you need to get, you know, some imaging done from your dentist to make sure that your airway is open to where if you're forced to breathe through your nose, you can actually have oxygen exchange.
21:11 Steven Bartlett? And is there anything else that I could and should be doing to increase and improve my nitric oxide levels that we haven't talked about yet?
21:18 Speaker 01 Humming, you know, there are certain frequencies, we've done this in looking at nitric oxide coming out of the exhaled breath when you're humming. So certain frequencies can activate this enzyme, and it's dependent upon the volume of the nasal sinuses, so there's not one frequency that would work in every single person. Because the volume of your airways and oral cavity and sinuses was probably much different than mine.
21:40 Steven Bartlett? Give me an example, show me.
21:42 Speaker 01 Well, if you just, you know, like, ohms, like you do in meditation or just simple humming, you could actually, so if I had my ozone or gas phase analyzer here, I could hum,
21:55 Speaker 01 and I could detect nitric oxide coming out of my exhaled breath.
21:59 Steven Bartlett? Because of the frequency of the...
22:00 Speaker 01 Because of the frequency and activating the nitric oxide synthase enzyme. But if you take older patients, and we've demonstrated this, it's published years ago, and other groups have demonstrated this, older patients, that their enzyme isn't making nitric oxide, whether they do nasal breathing, or whether they do humming, there's no nitric oxide coming out. So again, this is an activator and a stimulator, but it's dependent upon the function of the enzyme that makes nitric oxide. If your enzyme is broken, humming, nasal breathing, exercise, isn't going to produce any nitric oxide.
22:31 Steven Bartlett? Is there anything else that I should be aware of if I'm trying to improve my nitric oxide levels?
22:36 Speaker 01 I think it's doing the things that disrupt it. Get rid of fluoride, get rid of mouthwash, stop using N-acids, stop eating sugar, anything that leads to an elevation in blood sugar, a balanced diet in moderation, moderate physical exercise, 20 to 30 minutes of sunlight a day.
22:51 Steven Bartlett? Sunlight?
22:52 Speaker 01 Sunlight. There's certain, at both ends of the visible spectrum, both are the UV spectrum and the full spectrum infrared. So those frequencies and vibrations, again, stimulate nitric oxide release. So the UV has enough energy to where it'll knock nitric oxide down to a cystine thione protein, and then the UV spectrum will release nitric oxide down to metals.
23:18 Steven Bartlett? So you mean, go out in the sunshine, but also those red light beds and stuff?
23:22 Speaker 01 Yeah, I have a red light bed, I have an infrared sauna that uses red lights in it, and I use it every day.
23:29 Steven Bartlett? For nitric oxide production?
23:30 Speaker 01 Yeah. And there's other benefits of light. You know, it can stimulate mitochondrial biogenesis, it improves energy production, it can lower blood pressure, lots of benefits of light therapy. And yet, we're programmed to not go outside. If we go outside, put on SPF 60 and intoxicate ourselves with these cancer-causing chemicals and sunscreen. It makes no sense.
23:54 Steven Bartlett? What you just listened to was a most replayed moment from a previous episode. If you want to listen to that full episode, I've linked it down below. Check the description. Thank you.
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