This simple morning habit can lower stroke risk

A simple morning habit can lower the risk of a deadly condition called stroke, which affects nearly 795,000 Americans each year. Keeping good oral hygiene by incorporating flossing in your daily routine can safeguard you from certain types of stroke, says new research presented at the American Stroke Association’s International Stroke Conference 2025.

The new study reveals that flossing at least once a week may lower the risk of ischemic stroke, cardioembolic stroke, and atrial fibrillation (AFib), all the types of strokes that can result in health complications.

The study led by Dr. Souvik Sen from the University of South Carolina School of Medicine sheds light on the importance of good oral hygiene for maintaining cardiovascular health.

“A recent global health report revealed that oral diseases — such as untreated tooth decay and gum disease — affected 3.5 billion people in 2022, making them the most widespread health conditions,” said study author Dr. Souvik Sen.

“We aimed to determine which oral hygiene behavior — dental flossing, brushing or regular dentist visits — has the greatest impact on stroke prevention,” added Sen, chair of the neurology department at the University of South Carolina School of Medicine.

The team of researchers found that flossing teeth at least once a week can lower many types of stroke risks. The practice is associated with 22% reduced risk of ischemic stroke, 44% lower risk of cardioembolic stroke and 12% lesser risk of AFib.

What is a stroke?

A stroke occurs when blood flow to the brain is disrupted. This happens when a blood vessel bursts or a blood clot blocks blood flow. Strokes can cause lasting brain damage, long-term disability, or death.

There are two main types of stroke according to Johns Hopkins Medicine:

Ischemic strokes: These are the strokes that are caused by blockage of an artery or, in rare cases, a vein. Most of the stroke, around 87% of them are ischemic.

Hemorrhagic stroke: These are the strokes caused by bleeding. About 13% of all strokes are hemorrhagic.

A cardioembolic stroke may occur when a blood clot travels from the heart to the brain and blocks blood flow to a part of the brain.

Atrial fibrillation or AFib describes a heartbeat that’s too slow, too fast or irregular. It may lead to stroke, heart failure or other complications.

The researchers explain that oral health is linked to inflammation and artery hardening. They say that flossing can reduce stroke risk by lowering oral infections and inflammation. Researchers stress that this habit is not only easy to incorporate but also quite inexpensive, affordable and accessible.

In Sen’s study, over 6,200 participants provided details about their flossing habits through a questionnaire and were tracked for 25 years. During the follow-up period, 434 individuals experienced strokes, and nearly 1,300 developed atrial fibrillation (Afib). The research found that more frequent flossing was associated with a greater reduction in stroke risk. Notably, this reduction in risk was independent of other oral hygiene practices, such as tooth brushing and regular dental checkups.

The research, which is yet to be peer-reviewed, will be presented at the American Stroke Association’s International Stroke Conference 2025.