A heart doctor has issued a significant warning about the link between the use of mouthwash and high blood pressure — and he is not the only one. Studies have identified a significant link between the regular use of mouthwash and raised blood pressure — and the science behind the finding may change the way you think about your morning routine.
Research Links Mouthwash to Hypertension
Research published in the journal Blood Pressure examined the habits of more than 1,000 participants and found that frequent, regular use of over-the-counter mouthwash was associated with an increased risk of hypertension. Scientists concluded: "In this study, frequent regular use of over-the-counter mouthwash was associated with increased risk of hypertension, independent of major risk factors for hypertension and several other potential confounders."
A separate study featured in Science Direct identified "unequivocal evidence" that the disruption of oral bacteria caused by mouthwash use "will suppress nitric oxide production... and negatively impact blood pressure". The mechanism at the heart of both findings is the same: antibacterial mouthwash destroys beneficial bacteria in the mouth that play a crucial role in the body's production of nitric oxide — a compound that widens blood vessels and helps regulate blood pressure.
Further Studies Confirm Blood Pressure Impact
A further study, published in the journal Free Radical Biology and Medicine, found that participants who used antibacterial mouthwash twice daily saw a measurable reduction in nitric oxide availability in the body, with researchers noting corresponding increases in systolic blood pressure compared to those who did not use mouthwash. The authors concluded that oral bacteria form a critical part of the body's cardiovascular regulation system — and that routinely eliminating them carries real physiological consequences.
The findings have prompted concern among health professionals. Dentist Mark Burhenne said: "Your mouthwash is sabotaging your blood pressure. In this study, when healthy people used chlorhexidine mouthwash for just one week, their blood pressure went up. When they STOPPED using it? Their blood pressure dropped by 3.5 mm Hg within three days. That’s the same effect you’d get from drastically cutting your salt intake."
Dentists Warn of Oral Microbiome Disruption
Dentist Kami Hoss argues that the problem lies in the indiscriminate nature of most commercial mouthwashes, reports the Mirror. He suggests that oral health amongst the general population remains relatively poor, with individuals either failing to care for their mouths properly or going to the opposite extreme by sterilising them so thoroughly that the delicate balance of the oral microbiome is disrupted.
Dr Hoss argues that our reliance on powerful mouthwash to eliminate most bacteria leaves behind only "the baddest, toughest, roughest little microbes around" and draws a comparison between mouthwash use and gardening: "If there was a weed growing in your garden, you wouldn't just throw acid and weed killer all over and kill everything, the way we do it in our mouth. [But] we take antiseptic mouthwash that kills everything. What we do in the mouth is a disaster right now."
Cardiac Surgeon Avoids Mouthwash
The concerns are shared by board-certified cardiovascular surgeon Dr Jeremy London, who frequently shares health guidance on social media and in interviews. In a video titled "stop using mouthwash", he said: "This is one thing I absolutely avoid as a cardiac surgeon. Two reasons. Number one: just like the remainder of your gastrointestinal tract your mouth has healthy bacteria and by killing that bacteria you injure the environment in your mouth."
"Number two, and this I find really interesting, there's a chemical reaction with that healthy bacteria which helps control your blood pressure and by destroying that healthy bacteria in your mouth you can actually cause high blood pressure. High blood pressure is a risk factor for both strokes and heart attacks."
Speaking on NBC network's Today programme, Dr London expanded on the subject, clarifying that beneficial bacteria in the mouth assist the body in producing nitric oxide, a compound involved in widening blood vessels and regulating blood pressure. He said: "You can actually increase your blood pressure simply by killing the bacteria in the mouth. And if you have a propensity to having high blood pressure, that can even be worse."
When listing things he personally avoids, mouthwash sits alongside smoking, vaping, alcohol, soft drinks and ultra-processed foods.
