Flossing May Reduce Stroke Risk

According to the most recent statistics from the American Heart Association, in 2022, 453 people died each day due to stroke in the United States.¹ With such dire outcomes, oral health professionals should be well versed on the relationship between the oral cavity and stroke risk.

Ischemic strokes, which account for approximately 87% of all strokes, occur when a blood vessel to the brain is blocked, usually by blood clots or fatty deposits. Variations of ischemic stroke include cardioembolic strokes, in which the heart pumps debris into the brain; thrombotic strokes, caused by a blood clot in large arteries in the brain; and lacunar strokes, which occur when clots develop in small arteries deep in the brain.^2,3

The Oral Connection

While various factors, including cardiovascular disease and diabetes have long been implicated in stroke events, current research indicates that poor oral health is also a player. This places new emphasis on the benefits of preventive oral care methods in halting the cascade of events that leads to a stroke.^2,3

A team of researchers recently concluded a longitudinal study exploring how flossing may lower the risk for stroke. The findings were presented at the American Stroke Association’s International Stroke Conference in Los Angeles.

Lead researcher Souvik Sen, MD, MPH, a professor and chair of the Neurology Department at the University of South Carolina School of Medicine in Columbia, noted that prior studies have shown a link between oral health, oral infection, and damage to white matter and small blood vessels in the brain. He added that this connection can also be seen in a buildup of plaque in the arteries that supply blood to the brain.³

Long-Term Study

While previous studies have identified an association between oral infection, stroke, and atrial fibrillation (AFib) — a cause of cardioembolic stroke —  the impact of preventive measures such as flossing on these types of strokes has been unknown.²

The researchers tested the relationship between flossing and the incidence of ischemic stroke, AFib, and stroke subtypes in an Atherosclerosis Risk in Communities cohort study.² Following 6,278 participants for 25 years, 65% of whom reported weekly flossing, the researchers sought to determine if the subjects would develop AFib or experience an ischemic stroke.

Telling Results

While the findings didn’t reflect a link between flossing and thrombotic or lacunar strokes, the analysis did find that, compared to nonflossers, those in the study who flossed at least once a week lowered their risk of ischemic stroke by 22%. Their risk of a cardioembolic stroke was 44% lower and their risk of AFib, which developed in 20% of study participants, was 12% lower.^2,3

Sen observed that because inflammation can contribute to the risk for stroke, regular flossing may well help reduce the risk of stroke and AFib. He notes that flossing alone won’t prevent a stroke but it is an important addition to healthy lifestyle.

References

1. American Heart Association. Heart and Stroke Statistics Update.
2. Sen S, Marchesan J, Wood S, et al. Dental flossing may lower the risk for incident ischemic stroke, cardioembolic stroke subtype and AF. 2025;56: Epub ahead of print.
3. Williamson L. Flossing may reduce risk for stroke and irregular heart rhythm. American Heart Association News.