Regular Flossing May Help Lower Stroke and AFib Risk

• Cardiovascular disease, including stroke, remains the number one cause of death for Americans.
• New research suggests that flossing and maintaining good oral health may help mitigate the risk of AFib and blood clot-related stroke.
• Flossing is a simple, inexpensive habit that can easily be added to a daily routine.

Cardiovascular disease, including stroke, remains the leading cause of death in the United States, according to the latest data from the American Heart Association (AHA).

Lifestyle interventions, including healthy dietary changes and regular exercise, are some of the most effective methods of prevention against cardiovascular disease (CVD).

A lesser-known tactic involves a secret weapon you might already have in your medicine cabinet: dental floss.

Flossing should be part of any regular oral care routine, but it could also have significant beneficial effects on heart and brain health.

“We have known that gum disease and dental caries are risk factors for stroke and heart attack. Flossing is already known to reduce the rate of heart attack,” Souvik Sen, MD, MPH, chair of the Department of Neurology, Prisma Health Richland Hospital and the University of South Carolina School of Medicine, and author of the research, told Healthline.

“Our research suggests that dental flossing can reduce the risk of stroke, and higher frequency of flossing leads to further reduction of stroke.”

Researchers analyzed the data of more than 6,000 participants in the ongoing Atherosclerosis Risk in Communities (ARIC) cohort study, which began in 1987. The study utilizes a comprehensive questionnaire to assess various lifestyle factors and behaviors on atherosclerosis (narrowing of the arteries).

Sen and his team were specifically interested in the association of flossing, independent of other oral care factors such as brushing and regular dentist visits, on cardiovascular disease outcomes.

About 65% of the cohort (4,092) reported flossing. Over a 25-year follow-up period, 434 participants experienced strokes, with 97 of those identified as a specific subtype called a cardioembolic stroke, in which a blood clot travels from the heart to the brain.

Compared to those who did not report flossing, flossers experienced a 22% lower risk of ischemic stroke and a 44% lower risk of cardioembolic stroke.

Flossing was also associated with a 12% lower risk of atrial fibrillation, the most common form of irregular heartbeat. AFib is also the leading cause of cardioembolic strokes.

“There is an increasing awareness of the role of inflammation in the development of AFib and it will be interesting to have more research into this association and, if true, the potential mechanism,” Rod Passman, MD, a professor of medicine and director of the Center for Arrhythmia Research at Northwestern University who wasn’t affiliated with the research, told Healthline.

“Studies like this are limited by the self-reporting and the potential for confounders — do people who floss also engage in other activities that may be good for their heart that may not be measured in the study,” Passman cautioned.

The mechanism for why flossing may reduce stroke risk isn’t yet certain, but researchers are honing in on the role of inflammation as a risk factor for heart disease.

“Oral health behaviors are linked to inflammation and artery hardening. Flossing may reduce stroke risk by lowering oral infections and inflammation and encouraging other healthy habits,” said Sen.

As with other forms of inflammation, evidence suggests that periodontitis may be linked to cardiovascular disease. The link also suggests that good oral health habits like brushing and flossing may be a potential lifestyle factor for reducing cardiovascular disease risk.

Researchers investigated additional links between oral health, the gut, and stroke risk and presented their findings this week at the American Stroke Association’s International Stroke Conference.

Lead researcher Shuichi Tonomura, MD, staff physician in the department of neurology at the National Cerebral and Cardiovascular Center in Osaka, Japan, identified an apparent association between the presence of the bacteria Streptococcus anginosus and stroke.

Streptococcus anginosus commonly lives in both the oral and gut microbiota, but Tonomura and his team found that it was abundant in the gut of stroke survivors.

In fact, the amount of streptococcus anginosus in the saliva and the gut was associated with both a higher risk of stroke and worse outcomes, including death and other major cardiovascular events, following a stroke.

“I want to propose that examining gut microbiota patterns has been suggested to be potentially useful for assessing stroke risk and prognosis,” Tonomura told Healthline.

Both Tonomura and Sen’s research highlights the complex relationship between oral health and cardiovascular disease, and points to new areas for research into prevention.

Tonomura suggested that Streptococcus anginosus could one day serve as a biomarker to help determine stroke risk and that targeting harmful bacteria through proper oral health strategies could lower your risk of stroke.

According to Sen, regular flossing may also be a relatively easy way to improve oral health and also help prevent cardiovascular disease.

“Dental flossing could be an added and inexpensive health behavior one could adapt to prevent one from having a stroke,” said Sen.

Doctors attributed nearly 1 million deaths to cardiovascular disease in 2022, the most recent year included in the AHA’s 2025 annual report on heart disease and stroke.

To put that in more concrete terms: on average, one person in the U.S. dies from CVD every 34 seconds.

“Heart disease remains the leading cause of death in the United States, a trend that has persisted for over a century,” corresponding author Latha P. Palaniappan, MD, FAHA, a professor of cardiovascular medicine at Stanford Medicine, told Healthline.

Cardiovascular disease is responsible for more deaths than all forms of cancer and accidental death (which includes drug overdose and car accidents) — the number two and three causes of death in the U.S. — combined.

Making meaningful, actionable changes to improve your overall health can help reduce your risk of cardiovascular disease. For better heart health, Palaniappan suggested following the AHA’s Life’s Essential 8 checklist:

• Eat better
• Be more active
• Quit tobacco
• Get healthy sleep
• Manage weight
• Control cholesterol
• Manage blood sugar
• Manage blood pressure

Cardiovascular disease, including stroke, remains the leading cause of death for Americans. Modifiable risk factors, including diet and exercise, continue to play a crucial role in lowering your risk.

Researchers are focusing on the role of poor oral health as a potential risk factor for cardiovascular disease. Conversely, good oral health habits, such as flossing, may reduce your risk, new research suggests.

Flossing may be a simple, inexpensive way to lower your risk of certain forms of cardiovascular disease, like AFib and stroke.