February 5, 2025 from Medscape
More Than a Clean Smile: How Flossing May Help Prevent Stroke
A new long-term study suggests that flossing your teeth may do more than improve your oral hygiene—it could help prevent serious health issues like stroke and atrial fibrillation (AF). The research, presented at the 2025 International Stroke Conference, found that regular flossing was significantly associated with a lower risk of ischemic stroke, especially the cardioembolic subtype, and a reduced incidence of AF.
Researchers followed more than 6,000 participants from the Atherosclerosis Risk in Communities (ARIC) study who had no prior history of stroke or AF. Over 25 years of follow-up, 434 strokes were documented. Participants who reported flossing at least once a week showed a notably lower risk of ischemic stroke, even after adjusting for factors like age, gender, blood pressure, diabetes, brushing frequency, and dental visits.
Inflammation and Heart-Brain Connection
Study lead Dr. Souvik Sen, a neurologist at the University of South Carolina, explained that flossing may reduce systemic inflammation caused by oral infections, which in turn may lower the risk of AF. He clarified that
“we knew that flossing regularly will lower the body’s level of inflammation, and the level of oral infection, but now, based on this study, we know it will reduce the rate of stroke, atrial fibrillation, and cardioembolic stroke.”
This inflammation-related pathway may help explain why flossing, more than brushing or routine dental checkups, was linked to reduced cardiovascular risk. While brushing helps maintain tooth surface cleanliness, flossing targets plaque and food buildup between teeth and along the gumline—areas where inflammation often begins.
The Data Behind the Claim
Among the 6,278 study participants, those who flossed (about 65%) had lower rates of hypertension, diabetes, and periodontal disease compared to those who didn’t. The risk reduction for cardioembolic stroke was especially strong, with an adjusted hazard ratio of 0.56. The benefit appeared to be linked to lower rates of AF, a known driver of stroke risk.
The analysis found no significant association between flossing and other stroke types such as thrombotic or lacunar strokes, suggesting that the benefit may be specific to stroke types related to irregular heart rhythms.
Public Health Potential
Flossing, a simple and low-cost habit, could play an important role in preventing strokes—particularly in areas with limited access to dental care. Sen called flossing “a very good primary prevention strategy” and emphasized that its benefits extend beyond conventional dental health.
The study also found a dose-response effect, meaning the more often people flossed, the greater their reduction in stroke risk.
Expert Perspective
Commenting on the findings, Dr. Daniel Lackland of the American Heart Association noted that the study offers “some part of dental hygiene” as a potential cardiovascular disease prevention tool. While more research is needed, especially randomized trials, the evidence suggests that daily flossing could be a small step with significant long-term benefits for heart and brain health.
As research continues to explore connections between inflammation, oral health, and chronic disease, this study offers a timely reminder that sometimes the simplest habits can have the biggest impact.
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