March 1, 2026, 12:17 pm | Read time: 5 minutes

The prognosis after an ischemic stroke is grim: around 20 percent of patients who suffer such a cerebral infarction die within 28 days. Could a simple preventative measure, such as daily flossing, reduce the risk of this deadly condition? Data from a long-term study investigating cardiovascular risk factors, including stroke and its clinical consequences, suggest that it could. What is behind this effect? FITBOOK took a look at the study.

Oral and Cardiovascular Health Are Closely Linked

Oral health and cardiovascular disease are now known to be closely linked. Inflammation of the gums, also known as periodontitis or periodontal disease, increases the risk of heart disease, including stroke. The mechanism is as follows: if bacteria from the gum pockets enter the bloodstream, they can cause chronic inflammatory reactions in the body, which in turn impair the function of the blood vessels. It is suspected that blood vessels actually harden. As a result, blood pressure increases, which puts more strain on the heart. Ultimately, the risk of suffering a heart attack or stroke increases. The more severe the periodontitis, the higher the risk.

The risk of suffering a stroke cannot be determined solely by one’s family history. A stroke is not hereditary, but the hereditary predispositions that increase the risk are, such as diabetes or hypercholesterolemia, which result in increased blood lipid levels. Other risk factors are also mentioned: Atrial fibrillation, age, high blood pressure, type 2 diabetes, high cholesterol levels, and smoking.

Flossing to Prevent Strokes – What a Study Investigated

In the past, preventive measures were based on what could be described as a generally healthy lifestyle: Engaging in physical activity, maintaining a healthy weight, consuming alcohol in moderation, abstaining from smoking, managing stress effectively, and ensuring adequate sleep. Interesting: In this context, an extreme backward tilt of the neck, such as when putting the head back in the hairdresser’s washbasin, is also discouraged. Pressure from the washbasin on the neck can lead to restricted blood flow—and in the worst case, result in a stroke.

In the past, this was the end of the list of measures that could be taken to protect against a stroke. Although the points on the list are specific, they are also quite extensive and therefore probably unattainable for many people. Against this backdrop, the results of this study, which examined a simple morning routine as a stroke risk reducer, are exciting: simple cleaning of the spaces between the teeth with dental floss.

Are People Who Floss Less Likely to Suffer a Stroke?

The so-called ARIC study filled this research gap. “ARIC,” short for “Atherosclerosis Risk in Communities,” has been investigating cardiovascular diseases, cardiovascular risk factors, and their clinical consequences for a quarter of a century. Health data from a total of 6,278 people were analyzed in order to clarify these possible correlations: Are people who floss regularly less likely to suffer a stroke? What about different types of strokes? And does this habit also reduce the risk of atrial fibrillation, the most important stroke risk factor?

All study participants had answered questions about flossing—65 percent of them had stated that they used it to clean between their teeth at least once a week. How many of them suffered an ischemic stroke at some point during the 25-year observation period? How many were diagnosed with atrial fibrillation during the study period? And did these figures differ from the group of people who did not use dental floss?

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Key Findings of the Study

The results were published in the specialist journal “Stroke.” Unfortunately, we only have access to a summary of the study results.¹ The American Heart Association quotes from the comprehensive report on its website^.2 It states:

• Regular cleaning of interdental spaces with dental floss reduced the risk of ischemic stroke by 22 percent.
• This effect was particularly clear in the case of cardioembolic strokes, where the risk was as much as 44 percent lower.
• However, there was no significant correlation for thrombotic and lacunar strokes.
• A slightly reduced risk association of 12 percent was also found for atrial fibrillation.

To explain: an ischemic stroke occurs when the blood flow to the brain is interrupted due to a clot. There are two types of ischemic stroke: Thrombotic stroke is caused by a blood clot in large arteries in the brain; embolic stroke is caused by a clot traveling from the heart to the brain. Lacunar stroke, on the other hand, is caused by clots in small arteries deep in the brain.

Conclusion: Flossing is an Effective Part of Cardiovascular Prevention

Flossing not only helps to remove pesky debris from between teeth, but it also helps to prevent these potential sources of inflammation from entering the bloodstream, where they can affect the health of our blood vessels. Clearly, flossing could be a simple but effective part of cardiovascular prevention! Despite certain limitations in its significance (it is only an observational study that does not prove a direct causal relationship—people who floss regularly may have a healthier lifestyle in general), the study is a significant contribution to research on oral health and stroke risk due to its large size and long observation period. It shows that regular flossing is associated with a lower risk of ischemic stroke, especially the cardioembolic form, and atrial fibrillation.