Eight years ago I shared a claim that surprised many people: the mouthwash on your bathroom shelf might be raising your blood pressure.
At the time it sounded unlikely to some and was dismissed by a few colleagues in dentistry and medicine. I maintained my position because the biology made sense: early research showed how the oral microbiome contributes to systemic nitric oxide production, and I expected more evidence to follow — which it has.
Since then, additional studies have reinforced that connection. One pivotal trial published in 2019 followed participants for three years and found striking associations among those who used antibacterial mouthwash twice daily:
- 49% higher risk of developing diabetes
- Nearly double the risk of developing high blood pressure
How can mouthwash affect blood pressure? The answer lies in how your body produces nitric oxide, a molecule that helps keep blood vessels relaxed and flexible. Roughly half of the nitric oxide your body generates begins with processes carried out by bacteria on the back of the tongue. Certain beneficial oral bacteria convert dietary nitrates into nitrites — the first step in creating nitric oxide.
Antibacterial mouthwashes indiscriminately kill these bacteria. Fewer bacteria means less conversion of nitrates to nitrites, which leads to reduced nitric oxide production. The result: blood vessels are less able to dilate and blood pressure can rise.
The good news is this effect can be reversed by supporting the nitrate–nitrite–nitric oxide pathway. Small behavioral changes restore and enhance nitric oxide production and can lower blood pressure. For example, a clinical trial showed that daily tongue scraping improved nitric oxide production and produced measurable reductions in blood pressure.
If you are trying to improve insulin sensitivity, are prediabetic, or already managing high blood pressure, consider these practical steps:
- Scrape your tongue every day to remove biofilm and support healthy bacteria
- Support the right oral bacteria by using products designed to be microbiome-friendly
- Choose toothpaste that protects the oral microbiome rather than wiping it out
- Eat nitrate-rich vegetables such as beets, celery, and leafy greens to provide substrate for beneficial bacteria
These are not just dental habits — they are cardiovascular and metabolic habits.
I’m especially encouraged because conversations between medical doctors and dental professionals are expanding. This month, two prominent MDs discussed how oral health affects brain and heart health on a major health podcast.
Dr. David Perlmutter, a neurologist, described nitric oxide as a “missing link” in cardiovascular and brain health. Dr. Jeremy London, a cardiothoracic surgeon, noted that neglecting oral hygiene — for example, not brushing or flossing — would fast-track someone toward heart disease.
It’s gratifying to see dentistry and medicine speaking the same language. When you share articles, forward emails, or keep these topics in conversation, you help move the oral–systemic connection into mainstream health discussions.
If you want to explore this collaboration further, here are practical next steps:
- Listen to expert interviews that discuss overlooked tools for assessing and reducing Alzheimer’s risk and daily habits that contribute to heart disease
- Use a brief letter to prompt communication between your dentist and medical providers so they can coordinate your care
- Consider continuing education or collaborative courses that bring dental and medical professionals together to learn about functional approaches to oral-systemic health
Remember: your mouth is not separate from the rest of your body. It is the front door to your overall health.
— Dr. B
P.S. I will explore the mouth–brain and mouth–heart connections in greater depth in my upcoming book with Penguin Life. What questions do you have? What important topics are missing from conversations with your dentist, doctor, or friends?
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References & Further Reading
Bondonno, C. P., et al. (2015). Antibacterial mouthwash blunts oral nitrate reduction and increases blood pressure in treated hypertensive men and women. Free Radical Biology and Medicine, 94, 36–46.
Joshipura, K. J., et al. (2017). Antiseptic mouthwash use and pre-diabetes/diabetes among overweight/obese adults: A cross-sectional study. Nitric Oxide, 71, 14–20.
Kapil, V., et al. (2013). Human inhibition of oral bacteria reduces the nitrate-nitrite-nitric oxide pathway, blood pressure, and exercise performance. Nitric Oxide, 26(4), 197–206.
Burhenne, M. (2018). Why I Never Recommend Mouthwash. Ask the Dentist.
Burhenne, M. (2019). The Oral Microbiome: What It Is and Why It’s So Important. Ask the Dentist.
Burhenne, M. (2020). Tongue Scraping: Benefits for Oral and Overall Health. Ask the Dentist.
Burhenne, M. (Podcast, 2021). How the Oral Microbiome Impacts Your Whole Body. Ask the Dentist Podcast, Episode 3.
Petersen, C., et al. (2021). The role of oral bacteria in cardiovascular disease. Journal of Oral Microbiology, 13(1), 1887690.