People with both gum disease and cavities face an 86 per cent higher risk of stroke compared with those with healthy mouths, a long-term study has found.
The research, which tracked nearly 6,000 adults over 20 years, also linked poor oral health to a 36 per cent greater likelihood of heart attacks and other cardiovascular problems.
Researchers from the University of South Carolina found that adults who visited the dentist regularly were 81 per cent less likely to have both gum disease and cavities.
Study author Dr Souvik Sen said: “We found that people with both cavities and gum disease had almost twice the risk of stroke compared to people with good oral health, even after controlling for cardiovascular risk factors.
“These findings suggest that improving oral health may be an important part of stroke prevention efforts.”
The study followed 5,986 people with an average age of 63, none of whom had experienced a stroke at the start.
Each participant underwent a dental exam to determine whether they had gum disease, cavities, or both, and was placed into one of three groups: healthy mouth, gum disease only, or gum disease with cavities.
Ischaemic strokes — the most common type — occur when a blood clot or blockage restricts oxygen and nutrient flow to the brain.
Participants were tracked over two decades through phone interviews and medical records to identify those who later suffered a stroke.
Among 1,640 people with healthy mouths, 4 per cent had a stroke. In comparison, 7 per cent of those with gum disease alone and 10 per cent of those with both gum disease and cavities experienced one.
After adjusting for factors such as age, smoking and body mass index, the researchers found that people with both gum disease and cavities had an 86 per cent higher risk of stroke than those with healthy mouths. Those with gum disease alone had a 44 per cent greater risk.
Beyond stroke risk, the researchers found that participants with both gum disease and cavities had a 36 per cent higher likelihood of major cardiovascular events such as heart attacks, fatal heart disease or stroke.
Regular dental check-ups appeared to make a significant difference. Participants who visited the dentist routinely were 81 per cent less likely to have both conditions and had 29 per cent lower odds of gum disease alone.
“This study reinforces that taking care of your teeth and gums isn’t just about your smile — it could help protect your brain,” said Sen.
“People showing signs of gum disease or cavities should seek treatment not only to preserve their teeth but possibly to reduce stroke risk.”
The researchers noted that participants’ oral health was assessed only once, at the beginning of the study, meaning any later changes were not captured.
They also acknowledged that other health or lifestyle factors may have influenced the results.
The findings add to growing evidence that oral and brain health are closely connected.
The researchers stressed, however, that their work shows a link rather than direct cause and effect.
