7 things I do every day to protect my nitric oxide

If you’ve heard me say that mouthwash can raise your blood pressure and wondered whether that’s true, you’ll like this newsletter…

The answer has to do with a molecule most people have never heard of, even though its discovery won a Nobel Prize in 1998.

Nitric oxide (NO) is a signal that tells your blood vessels to relax, which affects blood flow to your heart, your brain, your muscles, and everything else.

NO is also used by the body to send signals between nerve cells and to fight infection.

And it declines after age 30. In a study of 119 healthy adults, the blood vessels’ nitric oxide-dependent ability to relax was already falling by their thirties. By their sixties it was about 85% lower.

Bacteria on the back of your tongue do much of the work of converting the nitrate in a salad into nitrite, which your body can turn into nitric oxide. Human cells lack an efficient, dedicated nitrate reductase, so they depend on those bacteria for it.

In one small study of 19 healthy adults, suppressing those bacteria with chlorhexidine cut oral nitrite production by about 90%, and blood pressure rose by 2 to 3.5 mmHg within a day.

Here are seven things I do every day with that pathway in mind.

1. I avoid routine use of mouthwash. The chlorhexidine study above is why. Antibacterial rinses can have valid short-term uses, so don’t stop a prescribed rinse without asking why you need it and how long to use it.
2. I brush with a nitrate-containing toothpaste. I use Fygg’s +NO toothpaste, which I developed with nitric oxide researchers. This toothpaste delivers nitrate, the raw material those bacteria convert, straight to the tongue twice a day, with no antiseptic ingredients working against them. I think this is where toothpaste is headed.
3. I gently clean my tongue. The tongue is an important home for nitrate-reducing bacteria. Tongue cleaning thins a thick dysbiotic biofilm, helps with bad breath, and energizes the oral microbiome first thing to allow it to do its job converting nitrates to nitrites.
4. I eat nitrate-rich greens. Leafy vegetables provide the nitrate that oral bacteria use as a substrate. My daily salad includes endive, frisée, arugula, and radicchio with a generous amount of olive oil and a touch of balsamic.
5. I breathe through my nose, and I use mouth tape as a cue at night. Habitual mouth breathing can leave the mouth extremely dry, which reduces saliva’s buffering and protective functions. I noticed this in my patients for years. Nasal breathing also carries nitric oxide produced in the paranasal sinuses into the lungs. I breathe freely through my nose, so gentle, easily removable tape helps keep my lips closed while I sleep. Mouth tape should not be used to force breathing through an obstructed nose, or in place of an evaluation for snoring, gasping, or suspected sleep apnea. Sometimes I do this exercise to decongest before going to bed.
6. I protect my gum health. I brush thoroughly, floss, and treat inflammation early. In a small exploratory study, people with advanced periodontitis did not get the expected blood pressure response to nitrate-rich beet juice. After periodontal treatment, the response returned. A small study, but more is coming in this exciting area of oral health research as it pertains to NO and systemic health.
7. I exercise. Short 30 minute HIT training three times a week and everyday walking and activity supports endothelial nitric oxide production, a pathway that complements what happens in the mouth.

Which of these seven are you already doing?

Until next week,

Dr. B

The studies in this issue

1. The obesity and mouth bacteria study (628 adults): Shibl AA et al. “Integrative multi-omics analysis reveals oral microbiome-metabolome signatures of obesity.” Cell Reports, 2026. Read it
2. Treating gum disease lowers HbA1c: Simpson TC et al. “Treatment of periodontitis for glycaemic control in people with diabetes mellitus.” Cochrane Database of Systematic Reviews, 2022. Read it
3. Mouthwash and prediabetes (945 adults, 3 years): Joshipura KJ et al. “Over-the-counter mouthwash use and risk of pre-diabetes/diabetes.” Nitric Oxide, 2017. Read it
4. Mouthwash, nitric oxide and blood pressure: Kapil V et al. “Physiological role for nitrate-reducing oral bacteria in blood pressure control.” Free Radical Biology and Medicine, 2013. Read it
5. GLP-1 drugs and your mouth, including dry mouth: Bijoch J. “Oral Health Implications of GLP-1 Receptor Agonists and Other Incretin-Based Therapies.” Journal of Clinical Medicine, 2026. Read it

If you want to go deeper

• Nitric oxide bacteria and insulin resistance: Goh CE et al. “Association Between Nitrate-Reducing Oral Bacteria and Cardiometabolic Outcomes: Results From ORIGINS.” Journal of the American Heart Association, 2019. Read it
• Where the obesity and mouth bacteria question started: Goodson JM et al. “Is Obesity an Oral Bacterial Disease?” Journal of Dental Research, 2009. Read it
• Toddlers, weight gain and mouth bacteria: Craig SJC et al. “Child Weight Gain Trajectories Linked To Oral Microbiota Composition.” Scientific Reports, 2018. Read it