Healthy Teeth and Gums Tied to Better Brain Health

Adults who are genetically prone to poor oral health may be more likely than others to show brain changes associated with cognitive decline, a new study suggests.

Brushing your teeth regularly may also protect your brain.Getty Images

People who are genetically predisposed to cavities and other dental issues may be more likely to develop structural changes in the brain that are associated with cognitive decline, preliminary results from a new study suggest.

Previous research has linked oral health issues like gum disease, missing teeth, poor brushing habits, and plaque buildup to an increased risk of stroke and risk factors for heart disease like high blood pressure.

“What hasn’t been clear is whether poor oral health affected brain health, meaning the functional status of a person’s brain, which we are now able to understand better using neuroimaging tools such as magnetic resonance imaging, or MRI,” lead author of the new study, Cyprien Rivier, MD, a neurology researcher at the Yale School of Medicine in New Haven, Connecticut, said in a statement.

“Studying oral health is especially important because poor oral health happens frequently and is an easily modifiable risk factor,” Dr. Rivier said. “Everyone can effectively improve their oral health with minimal time and financial investment.”

Poor Oral Health Genes Tied to Structural Damage in the Brain

For the new study, researchers examined data on about 40,000 adults with no history of stroke who participated in the UK Biobank, an ongoing medical study. Participants were screened for more than 100 genetic variants known to predispose people to cavities, dentures, and missing teeth later in life. Participants also had brain MRI scans to look for structural damage and so-called white matter hyperintensities, both of which are associated with an increased risk of stroke and impairments in memory, balance, and mobility.

People who were genetically prone to cavities, missing teeth, or needing dentures had a larger amount of white matter hyperintensities and structural damage visible on their MRI images, according to preliminary study findings presented at the American Stroke Association’s International Stroke Conference 2023 in Dallas.

“Poor oral health may cause declines in brain health, so we need to be extra careful with our oral hygiene, because it has implications far beyond the mouth,” Rivier said. “However, this study is preliminary, and more evidence needs to be gathered — ideally through clinical trials — to confirm improving oral health in the population will lead to brain health benefits.”

More Data Is Needed to Explain the Link Between Oral Health and Brain Health

Beyond its preliminary nature, one limitation of the study is that results from the U.K. Biobank, with predominantly white, European participants, may not represent what would happen for people of other racial and ethnic backgrounds.

It’s also not clear from the study whether good oral health habits might prevent changes in the brain associated with stroke and cognitive decline, or how big a role genetics may play in this relationship, Joseph Broderick, MD, a professor and director of the University of Cincinnati Gardner Neuroscience Institute in Ohio, said in a statement.

“Environmental factors such as smoking and health conditions such as diabetes are much stronger risk factors for poor oral health than any genetic marker — except for rare genetic conditions associated with poor oral health, such as defective or missing enamel,” said Dr. Broderick, who wasn’t involved in the new study.

“It is still good advice to pay attention to oral hygiene and health,” Broderick added. “However, since people with poor brain health are likely to be less attentive to good oral health compared to those with normal brain health, it is impossible to prove cause and effect.”