For decades, modern medicine has chased symptoms—high blood pressure, diabetes, cognitive decline—without fully addressing the root cause that connects them all. According to

Dr. Nathan S. Bryan, one of the world’s leading nitric oxide researchers, that missing link is nitric oxide itself.
   A biochemist trained under Nobel Prize–winning scientists, Dr. Bryan has spent more than 25 years studying how nitric oxide functions in the human body, why its production declines so rapidly with age, and how that decline fuels chronic disease. His work spans peer-reviewed research, patented therapies, dietary supplements, and FDA-bound drug development—including groundbreaking work targeting Alzheimer’s disease.
   Dr. Bryan sat down with Preferred Health Magazine  to explain why nitric oxide is foundational to human health, how everyday habits quietly destroy it, and what people can do—starting now—to restore the body’s natural ability to heal and thrive.  

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PHM: What first drew you to the study of nitric oxide, and how has your understanding evolved over time?
Dr. Bryan: I first got interested in nitric oxide in the late 1990s. I had a degree in biochemistry from the University of Texas, and at the time I was working on my PhD in molecular and cellular physiology at LSU School of Medicine. The Nobel Prize for Physiology or Medicine had just been awarded to three U.S. scientists for the discovery of nitric oxide, so it was clear this was an important field.
   During my training, my mentor had been working in nitric oxide research for over 20 years. One of the Nobel laureates, Lou Ignarro, came to LSU and gave a lecture and said something that stuck with me. He said, ‘Nathan, if we can figure out how to restore the natural production of nitric oxide, it’ll change the world and change the way we treat and manage chronic disease.’
   That statement was profound. From that point forward, the question became: how does the human body make nitric oxide, what goes wrong when people can’t make it, and how do we fix it? That’s what we’ve been focused on for the last 25 years.

 

PHM: For readers who may be unfamiliar, what exactly is nitric oxide—and why is it so essential to human health?
Dr. Bryan: Nitric oxide is a naturally produced signaling molecule. It’s how cells in the body communicate with one another. Most people recognize it as a vasodilator, meaning it relaxes blood vessels and improves circulation. That’s how it was first discovered. But nitric oxide does much more than that. It signals our own stem cells to mobilize and repair damaged tissue. It activates mitochondria, the energy-producing organelles of the cell. It also activates telomerase, the enzyme that prevents telomeres from shortening.
   When we look at longevity, shorter telomeres are associated with shorter lifespan, and longer telomeres with longer lifespan. So nitric oxide is directly tied to aging and longevity. Everything we know about health, performance, and human optimization depends on the body’s ability to make adequate nitric oxide.

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PHM: Does nitric oxide production decline with age—and when does that begin?
Dr. Bryan: Yes, and the data are very clear. We measure something called endothelial function, which is the ability of the lining of the blood vessels to produce nitric oxide. What we find is about a 10 to 12 percent decline per decade, starting in our 20s.
   By the time most people reach 40 or 50 years old, they’re producing only about 50 percent of the nitric oxide they once did. Those data are over 20 years old, but today we know this decline doesn’t have to happen. We now understand what causes endothelial dysfunction, what leads to nitric oxide deficiency, and—most importantly—how to prevent it. That’s the goal: stopping the decline before it leads to disease.

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PHM: What everyday factors contribute to nitric oxide loss?
Dr. Bryan: Anything that increases blood sugar shuts down nitric oxide production. That’s why continuous glucose monitors are so valuable—they show you how your body responds to certain foods. We don’t want glucose spikes or insulin spikes.
   Nitric oxide is required for insulin to do its job and move glucose into the cell. Excess glucose, on the other hand, shuts down nitric oxide production. That creates a vicious cycle—hyperglycemia leads to insulin resistance and eventually type 2 diabetes. Glucose is sticky. It binds to proteins and enzymes and renders them dysfunctional.  Exercise is another major factor. Moderate physical exercise stimulates nitric oxide production, which is why exercise truly is medicine. But the biggest inhibitors of nitric oxide are things that kill the microbiome—specifically the bacteria in and on our bodies. Fluoride, antiseptic mouthwash, and antacids all interfere with nitric oxide production in profound ways.

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PHM: You’ve done extensive research on oral health and nitric oxide. Why is the mouth so important?
Dr. Bryan: Humans do not have the enzyme needed to convert dietary nitrate into nitric oxide. We are 100 percent dependent on bacteria that live on the crypts of the tongue to do that. Fluoride is antiseptic. It’s added to toothpaste and drinking water to kill bacteria. Mouthwash kills bacteria. When we published studies showing that mouthwash use raises blood pressure, people were shocked—but it makes sense when you understand the biology.  When you kill these bacteria, you lose the ability to make nitric oxide from your diet and recycle the nitric oxide your body produces. Every chronic disease we know of is associated with dysbiosis. We have to stop killing beneficial bacteria.

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PHM: What diseases are most strongly linked to nitric oxide deficiency?
Dr. Bryan: When you look at chronic disease—cardiovascular disease, erectile dysfunction, autoimmune disease, pulmonary disease, Alzheimer’s—they all share four common denominators. There’s reduced blood flow, runaway inflammation, oxidative stress, and immune dysfunction. All of that happens because we’ve lost the ability to produce nitric oxide.
   Nitric oxide dilates blood vessels, reduces inflammation, inhibits oxidative stress, and corrects immune dysfunction. It’s the foundational molecule for health and longevity.

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PHM: Why are you particularly excited about nitric oxide’s role in Alzheimer’s disease?
Dr. Bryan: Alzheimer’s is a vascular and metabolic disease. There’s always reduced blood flow to the brain and insulin resistance—we even call it type 3 diabetes.
Companies have spent billions developing monoclonal antibodies against amyloid plaques, but those drugs don’t work because plaques are a consequence, not the cause.
Nitric oxide restores blood flow to the brain, improves glucose uptake, prevents protein misfolding, and restores cognitive function. I don’t believe nitric oxide will eradicate Alzheimer’s—I know it will. And I believe we can even regress disease.

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PHM: Are there early warning signs of nitric oxide deficiency?
Dr. Bryan: Yes, there’s a clear hierarchy of symptoms. The first is sexual dysfunction—in both men and women. About 50 percent of men over 40 report erectile dysfunction, and it’s showing up in people as young as their 20s now. That’s the canary in the coal mine. If you can’t dilate the blood vessels of the sex organs, you can’t dilate the blood vessels of the heart or brain. Next comes high blood pressure, insulin resistance, exercise intolerance, brain fog, dementia, and eventually Alzheimer’s. The body tells us something is wrong long before catastrophic disease develops.

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PHM: What is the most important message you want readers to understand about nitric oxide?
Dr. Bryan: With over 200,000 papers published, it’s clear that your body cannot heal or perform optimally without nitric oxide.  It’s the missing molecule that most people—and much of medicine—have ignored for the last 20 to 30 years. We have to put nitric oxide front and center, understand what disrupts it, and start restoring its natural production if we want to prevent age-related disease. 

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To learn more about the benefits of Nitroc Oxide, to purchase Dr. Nathan Bryan's new book,
The Secret of Nitric Oxide: Bringing the Science to Life or to purchase n1o1 products please visit  www.N101.com. Be sure to check out Dr. Nathan Bryan's interview at 
https://www.youtube.com/@PreferredHealthMagazine