Flossing your teeth at least once a week may do more than just keep your smile healthy—it could also help protect your brain and heart.
A new study, to be presented at the American Stroke Association’s International Stroke Conference 2025, found that people who flossed regularly had a lower risk of certain types of stroke and irregular heartbeats.
Poor oral health is one of the most common health issues worldwide. In 2022, untreated tooth decay and gum disease affected an estimated 3.5 billion people globally. Gum disease and other oral infections are known to cause inflammation, which may contribute to artery hardening and other cardiovascular problems.
The research team, led by Dr. Souvik Sen of the University of South Carolina School of Medicine, wanted to find out which oral hygiene habits—flossing, brushing, or regular dentist visits—had the biggest impact on stroke prevention.
They analyzed data from over 6,000 people participating in the long-running Atherosclerosis Risk in Communities (ARIC) study. Participants answered detailed questions about their dental habits, health history, and lifestyle.
Over 25 years of follow-up, 434 people had a stroke. These included 147 strokes from large artery clots, 97 from clots that traveled from the heart (cardioembolic strokes), and 95 from small artery disease.
In addition, 1,291 participants developed atrial fibrillation (AFib), the most common type of irregular heartbeat, which can raise stroke risk.
The analysis showed that people who flossed at least once a week had a:
– 22% lower risk of ischemic stroke (caused by clots)
– 44% lower risk of cardioembolic stroke (clots traveling from the heart)
– 12% lower risk of developing AFib
These benefits were independent of other oral health habits, such as brushing and regular dental checkups. The researchers also found that flossing more often was linked to an even lower stroke risk. Flossing was also associated with fewer cavities and less gum disease.
Dr. Sen explained that flossing may help reduce stroke risk by lowering oral infections and inflammation, which can affect the heart and blood vessels. “Flossing is a healthy habit that is easy, affordable, and accessible to everyone,” he said.
While the study’s results are promising, there are some limitations. The data on flossing came from self-reported questionnaires, and researchers did not track whether people’s flossing habits changed over time. The study also focused on stroke and heart outcomes,
not other health effects.
Experts say that if future research confirms these results, flossing could potentially be included in the American Heart Association’s “Life’s Essential 8” list of key factors for heart and brain health, alongside healthy diet, exercise, sleep, and managing blood pressure,
cholesterol, and blood sugar.
The ARIC study began in 1987 and is still ongoing. Of the more than 6,200 participants analyzed, the average age was 62, 55% were women, 82% were white, and 18% were Black. People with total tooth loss, dental implants, or certain medical conditions were excluded from the analysis.
This research adds to the growing evidence that a healthy mouth may be linked to a healthy heart and brain—and that a little bit of floss could go a long way.
If you care about stroke, please read research about Thanks to his wife’s quick reaction, postal worker fully recovered from a stroke and findings of new hope for people with irregular heartbeat to prevent stroke.
For more about stroke, please read research about Stronger high blood pressure treatment may help prevent stroke in older people and findings of Stroke death risk increases again after falling for 40 years.
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