Flossing your teeth at least once a week may reduce your risk of stroke and irregular heartbeat, according to a preliminary study to be presented next week at the American Stroke Association’s International Stroke Conference 2025 in Los Angeles.
“Flossing was also linked to better overall health, including lower blood pressure, healthier cholesterol levels, and lower chances of diabetes,” says study lead author Souvik Sen, MD, chair of the neurology department at the University of South Carolina School of Medicine and a neurologist at Prisma Health in Columbia, South Carolina.
Exploring the Link Between Oral and Heart Health
The researchers were looking to find out which oral hygiene behavior — dental flossing, brushing, or regular dentist visits — had the greatest impact on stroke prevention.
The study included about 6,300 people. About 65 percent said they flossed.
A detailed questionnaire gathered information about oral hygiene habits and dental visits, as well health status, including high blood pressure, diabetes, high cholesterol, smoking, and body mass index.
During the 25 years of follow-up, 434 participants had strokes, of which 147 were larger artery brain clots, 97 were heart-driven clots, and 95 were hardening of the smaller arteries. About 1,300 people experienced atrial fibrillation (also called afib), an irregular and usually very rapid heart rhythm.
Flossing Benefits May Extend Beyond Your Gums
In the new research, which hasn’t yet been peer reviewed, flossing at least once a week was linked to the following benefits:
21 percent lower risk of ischemic stroke, the most common type of stroke, which happens when a blood clot blocks a blood vessel in the brain (Flossing more than once a week was associated with an even greater reduction in risk.)
44 percent lower risk of cardioembolic stroke, which are blood clots traveling from the heart
12 percent lower risk of afib, which can lead to blood clots in the heart and increase the risk of stroke and heart failure
Researchers found a lowered risk associated with flossing whether or not people regularly brushed their teeth or got routine dental care.
Why Does Flossing Protect the Heart and Brain?
This isn’t the first study to find a link between oral health and stroke. Because of the connection, the American Heart Association recommends that people see a dentist and get regular dental checkups as part of a heart-healthy lifestyle.
But researchers were surprised by the reduction in atrial fibrillation risk. A recent study suggests that at least 10.5 million Americans have afib, much higher than previously thought.
Why would flossing specifically lower this risk? “Flossing leads to reduction in oral infections such as gum disease and caries [cavities],” says Dr. Sen. This results in less inflammation, which has been tied to atrial fibrillation by several possible mechanisms, he says:
Inflammation and oxidative stress promote atrial fibrosis (scarring) and structural remodeling, disrupting normal electrical conduction in the heart.
Inflammatory stress impacts heart rate variability and increases the risk of atrial fibrillation.
Inflammation damages the endothelial lining of blood vessels, which in turn increases the risk of blood clots. Afib patients with chronic inflammation have a higher risk of stroke and embolism.
Inflammation is also tied to hardening of the blood vessels (called atherosclerosis) that can lead to stroke and heart attack, says Sen.
Preliminary Study Doesn’t Conclusively Prove That Flossing Lowers Heart Disease Risk
Because this study was observational — it collected data on existing dental hygiene habits — it doesn’t prove that flossing is directly responsible for the reduction in stroke and afib risks.
“Flossing is great for your teeth, but linking it directly to stroke prevention is tricky,” says Harlan Krumholz, MD, a professor of medicine and director of the Yale Center for Outcomes Research and Evaluation in New Haven, Connecticut. Dr. Krumholz was not involved in the study.
“People who floss regularly often take better care of their health in general — eating well, exercising, and keeping up with medical care — so it’s hard to say whether flossing itself lowers stroke risk, or if it’s just part of an overall healthy lifestyle. Studies like this are interesting, but we need to know more to prove cause and effect,” he says.
A recent global health report revealed that oral diseases such as untreated tooth decay and gum disease affected 3.5 billion people in 2022, making them the most widespread health conditions in the world. In the United States, about 4 in 10 adults have some form of periodontal (gum) disease, such as gingivitis and periodontitis. In adults over 65, 6 out every 10 people have gum disease.
Bottom Line: Flossing Is an Easy and Affordable Way to Improve Health
“Flossing isn’t just good for your teeth — it might help protect your heart and brain, too,” says Sen.
“It’s a simple, affordable way to improve oral health and possibly prevent serious heart and brain conditions,” he says.
Tom Gavin joined Everyday Health as copy chief in 2022 after a lengthy stint as a freelance copy editor. He has a bachelor's degree in psychology from College of the Holy Cross.
Prior to working for Everyday Health, he wrote, edited, copyedited, and fact-checked for books, magazines, and digital content covering a range of topics, including women's health, lifestyle, recipes, restaurant reviews, travel, and more. His clients have included Frommer's, Time-Life, and Google, among others.
He lives in Brooklyn, New York, where he likes to spend his time making music, fixing too-old electronics, and having fun with his family and the dog who has taken up residence in their home.
Becky Upham has worked throughout the health and wellness world for over 25 years. She's been a race director, a team recruiter for the Leukemia and Lymphoma Society, a salesperson for a major pharmaceutical company, a blogger for Moogfest, a communications manager for Mission Health, a fitness instructor, and a health coach.
Upham majored in English at the University of North Carolina and has a master's in English writing from Hollins University.
Upham enjoys teaching cycling classes, running, reading fiction, and making playlists.
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Noubiap JJ et al. Minimum National Prevalence of Diagnosed Atrial Fibrillation Inferred From California Acute Care Facilities. Journal of the American College of Cardiology. October 2024.
