People who routinely floss their teeth at least once a week could reduce their likelihood of experiencing a stroke caused by a blood clot from the heart and strokes linked to an irregular heartbeat, like atrial fibrillation (AFib).
According to an initial study to be presented at the American Stroke Association’s International Stroke Conference 2025, flossing at least weekly may be associated with a decreased risk of strokes caused by blood clots obstructing brain blood flow and irregular heart rhythms. This conference will be held in Los Angeles from February 5-7, 2025, and it serves as a leading event for researchers and healthcare professionals focused on stroke and brain health.
“A recent global health report indicated that oral health issues—such as untreated cavities and gum diseases—affected 3.5 billion individuals in 2022, making them the most prevalent health conditions,” stated Souvik Sen, M.D., M.S., M.P.H, the lead author of the study and chair of the Department of Neurology at Prisma Health Richland Hospital and the University of South Carolina School of Medicine in Columbia, South Carolina. “Our goal was to identify which dental care practices—flossing, brushing, or visiting the dentist regularly—have the strongest influence on preventing strokes.”
The Atherosclerosis Risk in Communities (ARIC) study, one of the initial large-scale studies conducted in the U.S., evaluated people’s flossing habits through a detailed questionnaire involving more than 6,000 respondents. Among those who reported flossing, 4,092 hadn’t suffered a stroke, and 4,050 hadn’t been diagnosed with AFib.
Participants provided information regarding their hypertension, diabetes, cholesterol levels, smoking habits, body mass index, educational background, regular brushing, and dental visits. Throughout the 25-year monitoring period, 434 participants were reported to have strokes, which included 147 due to major artery clots, 97 caused by heart-derived clots, and 95 resulting from the hardening of smaller arteries. Additionally, 1,291 participants were reported to have experienced AFib.
The findings revealed:
- Flossing was linked to a 22% reduced risk of ischemic stroke, a 44% decrease in the risk of cardioembolic strokes (blood clots moving from the heart), and a 12% lower risk of AFib.
- This decreased risk was independent of other dental hygiene practices like regular brushing and dental check-ups.
- Increasing the frequency of flossing was associated with a greater reduction in stroke risk.
- Flossing also correlated with a decreased likelihood of developing cavities and periodontal diseases.
The researchers were notably surprised by the findings related to AFib. AFib is the most prevalent type of irregular heartbeat and can result in stroke, heart failure, or other cardiovascular issues. The American Heart Association estimates that more than 12 million individuals in the U.S. will have AFib by 2030.
“Practices related to oral health are related to inflammation and arterial hardening. Flossing might help decrease stroke risk by minimizing oral infections and inflammation while promoting other healthy habits,” Sen noted. “Many individuals are concerned about the costs of dental care. Flossing is a healthy habit that is simple to implement, inexpensive, and widely available.”
Some limitations of the study include that it relied on self-reported data and that the 25-year follow-up primarily focused on stroke and heart outcomes, without monitoring changes in flossing or other dental habits over time, according to Sen.
“This study provides additional insights into specific dental health practices that could be connected to stroke risks and the potential reduction of those risks. With further investigation, dental health behaviors might be included in the ‘Life’s Essential 8’ risk factors, which encompass diet, physical activity, nicotine use, sleep, body mass index, blood pressure, blood glucose, and blood lipids,” said Daniel T. Lackland, Dr.P.H., FAHA, a member of the American Heart Association EPI and Stroke Council, and a professor of epidemiology and director of the Division of Translational Neurosciences and Population Studies at the Medical University of South Carolina in Charleston. Lackland did not participate in this study.
Additional information about the study includes:
- The study commenced in 1987 and remains ongoing.
- From the 6,258 participants, 82% were self-reported white adults and 18% Black adults, with an average age of 62 years, and 55% were women.
- Individuals were excluded if they had complete tooth loss, dental implants, heart disease, organ transplants, artificial joints, implanted heart valves, stents, or had undergone major surgery.
