The Diary Of A CEO with Steven Bartlett - Most Replayed Moment: Mouthwash REVERSES The Benefits Of Exercise! Dr Nathan Bryan

Episode Date: April 3, 2026

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. Listen to the full episode here: Spotify: https://g2ul0.app.link/JbS4DZVXV1b Apple: https://g2ul0.app.link/3WbhlB1XV1b Watch the Episodes On YouTube: https://www.youtube.com/c/%20TheDiaryOfACEO/videos Nathan Bryan: https://n1o1.com/about-dr-nathan-bryan/?srsltid=AfmBOooOFqsJRAP7whrtk26AsE0bI1-NrNlxbJVP-uhBoHYLuAEPy673

A few times of year, our team travels all over the world to interview guests who aren't able to record in one of our studios. And whenever these trips get confirmed, the first thing we book is a place on Airbnb so that the entire team can stay together. And over time, we've developed a small checklist for wherever we stay. Obvious things like incredibly fast Wi-Fi are a must. And a big dining table so we can all work somewhere together. Then there's less obvious things like a coffee machine to keep the team going, a living room big enough for planning meetings. And all of these things, the small things, the big things, they really do make the space. work for a team like ours. So if you've ever thought about hosting on Airbnb but haven't felt

sure if your place is right, remember that it might have exactly what someone's looking for. Hosting on Airbnb is easy and it's a smart way of making a bit more extra money on the side. All you have to do is choose the dates that work for you. Your home might be worth more than you think. Find out how much at Airbnb.ca.ca slash host. 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? Well, I think the most important thing we've learned is what you shouldn't be doing. Yeah. 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 U.S. is the organization task with if there's any, kind of risk of exposure of 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. And as I mentioned before, or most toothpaste has fluoride in it. And if you read the back of your toothpaste, it will tell you, at least in the U.S.,

I don't know about it 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-size 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, P-sized amounts of toothpaste. And a P-sized amount of toothpaste contains about half a milligram of fluoride. Now, if you're using 10, 20 times more than that P-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 bucocococin, the oral cavity, and it becomes systemic. I'm not going to use it anymore. No, you shouldn't. What should I use instead? You have to use a non-fluorinated toothpaste. And what about things like tongue scrappers? No, tongue scraper is 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. 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. Because it just looks strange. 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? Well, if you're going to plant a garden, do you plant a garden on untilled soil? Listen, I know nothing about gardening.

That's kind of the wrong guy, so maybe, yes. I grow my own food. Okay. So you have to till the soil, right? You've got to break up the soil so the seeds actually can be irrated, and you just 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 coming in there. But it's kind of like tilling the soil, and it's increasing the diversity of the dorsal part of the tongue, the microbiome. So my girlfriend was right? 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.

Interesting. Just 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. So you want to tongue scrape

and then use a toothbrush without fluoride toothpaste? Absolutely. Absolutely, and no anticeptic mouth rinse. Okay. And what about going to dental hygienists and things like that? Do you think that's an advisable idea? Because once every quarter or so,

I'll go and see a dental hygienist just to get everything sort of cleaned out. No, I think that's a good proactive practice, because you need to look at the health of the gum tissue and the gingival tissue and a routine clean and scraping the plaque off the teeth and making sure you have good mineralization of the enamel of the tooth is good, but never let them do a fluoride rinse on you.

Okay. 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? Yeah, there's also data showing that if you use mouthwash, you lose the cardioprotective benefits of exercise. 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 and blood pressure. What's the mechanism now?

Well, because you're killing the oral microbiome that's partly responsible for production of nitric oxide. And nitric oxide. Without nitric oxide, you get constriction of blood vessels, and it leads to high blood pressure. That's crazy. And is there a link between our hormone levels, things like my testosterone levels, and the nitric oxide? Yeah, so this is a two-way street. So in men, testosterone activates nitric oxide production. Okay.

In women, estrogen activates and stimulates nitric oxide production. Okay. 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. Got you. So taking testosterone or estrogen therapies helps to increase my nitric oxide levels? As long as the enzyme is functional and coupled, which means that we have to understand the enzyology and about chemistry of that reaction to where when it's exposed to, testosterone, the cell can actually make nitric oxide in response. 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. Well, think about it. I mean, there's other agnes, too, like vitamin D. I mean, most Americans under deficient 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 related to vitamin D deficiency,

which is activating or stimulative 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. 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? 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. Okay.

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 syrup, 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 glucose, then you should avoid that. because glucose as the name applies is glue, right? It's sticky. And if you have a soda and you spill it on your countertop, you come back the next day, it's sticky, right? Well, 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 marker of long-term glucose control. If you have hemoglobin A1C, greater than 5.7, you're diabetic.

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 confirmation, and it can't do its job.

For instance, it can't make nitric oxide. So sugar is an absolute poison, and it kills many enzymes and binds to everything. And it lowers nitric oxide production? Absolutely. That's why diabetics have a 10-time higher incidence of heart attack, 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 is 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. Just a bit of a tangent now. You mentioned that's why they have open wounds that don't heal. Yeah, diabetic ulcers. Okay, so nitric oxide's playing a healing role in wounds and scars? Absolutely. 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 passed out and got taken away by an ambulance. But I was just left with this big scar on the back of my head, which I've had like glue stitched. So I'm wondering, I'm like if I... 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. And how do I do that?

Is it... Yeah, so you take one pump from each side. So one pump from this side. Turn it around, one pump from the other. Yeah. 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. Okay, well, we shall. We shall see if that worked. So back on this point of food, then, so sugar's bad. Sugar's bad. Yeah, you've got to 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. Yeah. 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 got to 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's simple. And why did you write a book about beet roots? Beats, yeah, the beats hit the, really the airways back in 2012, in the London Olympic Games. 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 leaders of beetroot juice and causing a lot of. a lot of gastric discomfort causing diarrhea. Their urine and their feces would turn red,

and a lot of people 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. They didn't contain any nitrate, no nitrite. They were just, we called them dead beats. They're dead beat product.

And so I thought if people, if consumers are out there looking, for beats, because they've been shown to enhance their performance, but that enhancement and performance was dependent upon the beat'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 bead products that you can go to your local nutrition store or pharmacy, buy off the shelf, and we would use those as placebo 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 beats that are so important? What's the

mechanism and what is necessary in those beats 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 they're oral hygienic practices. I'm trying to find the page in your book, but there was a page in your book where you describe beach root as the most as the most underappreciated food in the history of eating. Yeah, that may be in the beat the odds.

I thought it was in this book. 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 beads 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. But unfortunately today, the beets that are grown, at least in America,

really are nutrient depleted just like most of the food. So would you recommend people eat beet roots? No, because, 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.

There's a graph in front of me here, printed off, which shows the rise in antacid medications. Oh, yeah, from 2004 to so a 20-year period, we're seeing, what is that, almost a quadrupling of the use of an acids. And this is globally, or is this in the U.S.? That's worldwide, I believe. Yeah, worldwide. Now, this is a problem. I mean, 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 plant-based protein. 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, micro-nutrients, are absorbed in the lumen of the stomach. And if the stomach 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 Gavaskung. No, these are like the prylasek, the previsids, the nexium, the prescription medications are omeprosol. pentoporzole. These, today in the U.S., I think, is probably worldwide, you don't even need a prescription for these from your physician.

You can go to your local drug store, and you can buy these what we call proton pump inhibitors or PPIs. We're about Tums. Over the Kion. So there's a difference in, so Toms and things like baking soda are a buffer, right? Sodium bicarb or calcium carbonate. And it's a buffer, right?

So if you have an acute bout of hypersecretion of acid, you can take a tombs or some buffer, some base, alkaline substance, to neutralize the acid. Neutralizing acid is completely different than inhibiting its natural production in the polyoric cells of the stomach. So what is the difference between something? Have you heard of Gaviscon before? Yes. Yeah. What's the difference between like a Gaviscom? Well, there's certain classes of an acids. 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 U.S. I mean, the main drugs used here are Polysicnexium previsid. Those are the over-the-counter. And then the main prescription medications are the Omeprosal and the pentopresol. Gaviscon is a commonly used antacid brand, and the active ingredients are aluminum hydroxide and magnesium carb carbonate. Oh, so Gaviskan. So, number one, it's got aluminum in it, which you should absolutely be avoided. But yeah, it looks like a buffer. It's got an hydroxide, aluminum hydroxide, which is a strong base, so it's neutralizing the stomach acid production.

But it's a neutralizing agent, but anything that contains aluminum, you should absolutely avoid. So I mentioned her a few times today, but my girlfriend's a breath practitioner, which runs a business called barleybreadthwork.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 link? 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 bronchules, the lower airway.

It's dilating those bronchials. 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. 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.

Oh, yeah, again, going over the past 20 years. Yeah, no, I think there's a lot of people. I mean, obviously your girlfriend, there's Patrick McEwen in the UK. Came into Dragonsden, I made him an offer in Dragonsden. Yeah. Now, I think the benefits of that are pretty well, and mechanistically we understand the benefits of it. So the mouth breathers are not only bypassed,

this natural nitric oxide production pathway, but when you mouth breathe, it completely changes the microbiome. 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. Interesting. Interesting. 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

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 you. your dentist to make sure that your airway is open to where if you force to breathe through your nose, you can actually have oxygen exchange. 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? Humming, you know, there are certain frequencies. We've done this and 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. Give me an example. Show me. 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, and I could detect nitric oxide coming out of my exhaled breath. Because of the frequency. 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 again, 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. Is there anything else that I should be aware of if I'm trying to improve my nitric oxide? I think it's doing the things that disrupt it. Get rid of fluoride, get rid of mouthwash,

stop using in acids, stop eating sugar, anything that leads to an elevation in blood sugar, a balanced diet in moderation, moderate physical exercise, 20 or 30 minutes of sunlight a day. Sunlight. 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, see. stimulate nitric oxide release. So the UV has enough energy to where it'll knock nitric oxide bound to a cysteine thial on protein. And then the UV spectrum will release nitric oxide down to metals. So you mean go out in the sunshine, but also those red light beds and stuff?

Yeah, the red light. I have a red light bed. I have an infrared sauna that uses red lights in it, and it's, I use it every day. For nitric oxide production? Yeah. And there's other benefits of light. You know, It can stimulate mitochondrial biogenesis. It improves energy production. It can lower blood pressure. But, yeah, lots of benefits of light therapy. And yet, we're programmed to not go outside. If we go outside, put on SPF60 and intoxicate ourselves

what these cancer-causing chemicals in sunscreen. I mean, it makes no sense. 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. A few times of year, our team travels all over the world to interview guests who aren't able to record in one of our studios. And whenever these trips get confirmed, the first thing we book is a place on Airbnb so that the entire team can stay together.

And over time, we've developed a small checklist for wherever we stay. Obvious things like incredibly fast Wi-Fi are a must. And a big dining table so we can all work somewhere together. Then there's less obvious things like a coffee machine to keep the team going, a living room big enough for planning meetings. And all of these things, the small things, the big things, they really do make this. space work for a team like ours. So if you've ever thought about hosting on Airbnb but haven't felt sure if your place is right, remember that it might have exactly what someone's looking for. Hosting on Airbnb is easy and it's a smart way of making a bit more extra money on the side.

All you have to do is choose the dates that work for you. Your home might be worth more than you think. Find out how much at Airbnb.ca.ca slash host.