Genetic Predisposition to Poor Oral Health May Be Linked to Declining Brain Health

New research suggests that adults who are genetically prone to poor oral health may be more likely to show signs of declining brain health compared to those with healthy teeth and gums.

Earlier research has shown that gum disease, missing teeth, and other signs of poor oral health, as well as poor brushing habits and lack of plaque removal, can increase the risk of stroke. According to the American Stroke Association, stroke is the number 5 cause of death and a leading cause of disability in the United States. Researchers have also found that gum disease and other oral health concerns are linked to heart disease risk factors and other conditions, such as 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,” said study author Cyprien Rivier, MD, MS, in a press release. “Studying oral health is especially important because poor oral health happens frequently and is an easily modifiable risk factor—everyone can effectively improve their oral health with minimal time and financial investment.”

Healthy lifestyle choices are known to also affect brain health, which includes the ability to remember things, think clearly, and function well. According to the study, 3 in 5 people in the United States will develop brain disease in their lifetime.

Between 2014 and 2021, investigators analyzed the potential link between oral health and brain health among approximately 40,000 adults (46% men, average age 57 years) without a history of stroke who were enrolled in the UK Biobank. Participants were screened for 105 genetic variants known to predispose individuals to have cavities, dentures, and missing teeth later in life. The researchers evaluated the relationship between the burden of these genetic risk factors for poor oral health and brain health.

Signs for poor brain health were screened via MRI images of the participants’ brains, including white matter hyperintensities that can impair memory, balance, and mobility; and microstructural damage, which is the degree to which the fine architecture of the brain has changed in comparison to images for a normal brain scan of a healthy adult of similar age.

The analysis found that individuals who were genetically prone to cavities, missing teeth, or needing dentures had a higher burden of silent cerebrovascular disease, as represented by a 24% increase in the amount of white matter hyperintensities visible on the MRI images. Those with overall genetically poor oral health had increased damage to the fine architecture of the brain, as represented by a 43% change in microstructural damage scores visible on the MRI scans.

“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 in the press release. “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.”

The analysis was limited because the UK Biobank only includes residents of the United Kingdom, and they are predominantly of European ancestry. Additionally, more research is needed among individuals from diverse racial and ethnic backgrounds.

“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 Joseph P. Broderick, MD, FAHA, a member of the Stroke Council at the American Stroke Association, in the press release. “It is still good advice to pay attention to oral hygiene and health.”

REFERENCE

Poor oral health may contribute to declines in brain health. News release. American Heart Association; February 2, 2023. Accessed February 7, 2023. https://newsroom.heart.org/news/poor-oral-health-may-contribute-to-declines-in-brain-health?preview=34c4