Poor dental health can nearly double your risk of stroke

People with both cavities and gum disease may face a sharply higher risk of ischemic stroke, according to new research.

The study stops short of claiming causation, but its message is hard to ignore: the worse your oral health, the higher your odds of a blocked-artery stroke.

“We found that people with both cavities and gum disease had almost twice the risk of stroke when compared to people with good oral health, even after controlling for cardiovascular risk factors,” said lead author Souvik Sen from the University of South Carolina.

“These findings suggest that improving oral health may be an important part of stroke prevention efforts.”

Ischemic strokes – by far the most common kind – happen when a clot or blockage starves brain tissue of oxygen and nutrients.

Gum disease and cavities might sound like mouth-only problems. However, this study adds weight to the idea that they’re also cardiovascular problems.

How dental health predicts strokes

Researchers analyzed data from 5,986 adults, with an average age of 63, none of whom had a prior stroke at the start.

Everyone received a dental exam and was placed into one of three groups: healthy mouth, gum disease only, or gum disease plus cavities. The team then tracked them for up to two decades using phone check-ins and medical records.

Outcomes split cleanly by dental status. Among the 1,640 people with healthy mouths, four percent had a stroke over the study period. In the 3,151 participants with gum disease alone, that rose to seven percent. In the 1,195 with gum disease plus cavities, it reached ten percent.

After adjusting for age, smoking, body mass index, and other clinical factors, the risk gaps held. Compared with people with healthy dental health, those with both gum disease and cavities had an 86 percent higher risk of ischemic stroke. Gum disease alone carried a 44 percent higher risk.

The team also examined “major cardiovascular events,” such as heart attack, fatal heart disease, or stroke. Here, the dual dental-disease group had a 36 percent higher risk than those with healthy mouths.

Routine visits cut stroke risk

The study also captured a practical, prevention-minded signal: people who reported regular dental visits had dramatically lower odds of walking around with significant dental disease.

Routine care was associated with an 81 percent lower likelihood of having both gum disease and cavities, and a 29 percent lower likelihood of gum disease alone.

That doesn’t prove dental visits themselves reduce stroke risk, but it does underline a simple truth – preventive care keeps oral disease at bay, and oral disease tracks with cardiovascular trouble.

“This study reinforces the idea that taking care of your teeth and gums isn’t just about your smile; it could help protect your brain,” Sen said.

“People with signs of gum disease or cavities should seek treatment not just to preserve their teeth, but potentially to reduce stroke risk.”

When mouth bacteria reach arteries

The biology isn’t speculative anymore. Chronic gum inflammation can open a pathway for oral bacteria and inflammatory molecules to enter the bloodstream.

Those signals can activate the immune system, damage the lining of blood vessels, and promote plaque buildup and clotting.

These are precisely the pathways that set the stage for heart attacks and strokes. Cavities themselves indicate bacterial overgrowth and enamel damage. When they coexist with periodontitis, they create a higher overall inflammatory burden.

That escalating burden shows up clearly in the numbers: healthy mouth (lowest risk), gum disease alone (higher), gum disease plus cavities (highest).

It’s a dose-like pattern that aligns with what cardiologists are learning about chronic inflammation and vascular disease more broadly.

Observations, not proof – yet

This was an observational study, meaning it can’t prove cause and effect. Dental status was measured once, at baseline.

The researchers didn’t track whether participants later treated gum disease, developed new cavities, or improved their hygiene.

Self-reported behaviors and unmeasured factors – such as diet quality, medications, access to care, and socioeconomic stress – could influence both oral health and stroke risk.

Still, the long follow-up, large sample, and consistent gradient in risk strengthen the case that the mouth-heart connection is real and relevant. The next step is prospective trials that treat oral disease aggressively and ask a simple question: do stroke rates fall?

Dental care that prevents strokes

While scientists work on that answer, the low risk playbook is already in hand. Brush, floss, and keep those routine cleanings. Treat bleeding gums, loose teeth, or persistent bad breath like the medical problems they are, not cosmetic annoyances.

And fold oral health into the rest of your prevention plan: control blood pressure, don’t smoke, manage cholesterol and diabetes, move your body, and eat like your arteries matter – because they do.

No single habit rewrites your risk. But this study adds a compelling line to the checklist: a healthy mouth might be one more way to keep blood flowing properly to the brain.

The study is published in the journal Neurology Open Access.

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