Researchers have long linked the bacteria that cause gum disease to a deadly risk: stroke. Those same microbes also contribute to diabetes and high blood pressure.
A team at the University of South Carolina found that people who flossed over a 25-year period had a 21 percent lower risk of ischemic stroke than those who didn’t. Ischemic stroke, the most common type, happens when blood flow to the brain is blocked, causing tissue death.
Over the same period, the risk of cardioembolic stroke — caused by a clot that travels from the heart — fell by 44 percent.
How Did Researchers Uncover the Link Between Dental Flossing and Stroke?
The study, which spanned 25 years, followed 6,278 U.S. residents. All participants reported their oral hygiene habits; 65 percent said they regularly used dental floss.
During the study period, 434 participants experienced a stroke: 147 had thrombotic strokes, 97 had cardioembolic strokes, and 95 had other subtypes.
The American Stroke Association presentation also reported that 1,291 participants were diagnosed with atrial fibrillation, a common condition that causes rapid heartbeats and can lead to stroke.
The researchers said, “Individuals who reported flossing their teeth had lower rates of ischemic stroke, cardioembolic stroke, and atrial fibrillation.”
Among people who regularly used dental floss, the risk of developing atrial fibrillation was 12 percent lower.
“Using dental floss reduces the risk of oral infections and gum disease linked to inflammation. It is reasonable to suggest that regular flossing could lower the likelihood of strokes,” the team said.
The study’s findings underscore the role of oral hygiene in overall health — brushing twice a day, flossing, and regular dental visits.
Dr. Suvik Sen, a neurologist at the University of South Carolina and the study’s lead author, said, “I wouldn’t say that flossing is the only thing you need to do to prevent stroke, but our results indicate that it’s another step toward a healthy lifestyle.”
Dr. Karen Fury, chair of the neurology department at Brown University, who was not involved in the study, added, “Many people neglect oral hygiene, and I hope this research brings attention to this important aspect of overall health.”
Where Else Is the Threat of Stroke Hidden?
At the same conference, researchers from the National Cerebral and Cardiovascular Center in Osaka, Japan, presented findings from another study.
The authors compared 189 patients who had suffered a stroke with 55 people who had not. In the intestines of those who recently experienced a stroke, researchers found Streptococcus anginosus, a bacterium linked to various health problems, including cavities.
Over two years of follow-up, patients with high levels of these bacteria in their intestines had a higher likelihood of dying or having another major cardiovascular event.
Dr. Shuichi Tonomura, the study’s lead author, said, “If there were a quick test to detect harmful bacteria in the mouth and intestines, we could use that information to assess stroke risk.”
