A study using data from over 6,000 participants in the Atherosclerosis Risk in Communities (ARIC) cohort found that flossing at least once a week was associated with a 22% lower risk of ischemic stroke, a 44% lower risk of cardioembolic stroke, and a 12% lower risk of atrial fibrillation (AFib). The findings were presented at the American Stroke Association's International Stroke Conference in February 2025.

The association held regardless of whether participants also brushed regularly or visited a dentist, suggesting that flossing contributes independently to cardiovascular risk reduction. Researchers attribute the effect to reduced oral infection and inflammation, both of which are linked to arterial disease and clot formation.

For dental professionals, the data add weight to patient counselling on flossing as a low-cost, accessible habit with measurable systemic benefits. The study's lead author noted that oral health behaviours could eventually be incorporated into established cardiovascular risk frameworks. Limitations include reliance on self-reported questionnaire data and no follow-up on flossing behaviour over the 25-year observation period.