Taking good care of your teeth -- brushing, flossing, regular dental checkups -- is, of course, important for good health. Now researchers say it's also vital for brain health.
While it was already clear that poor dental health could increase stroke and heart disease risk, a new study funds that adults who are genetically prone to have cavities, dentures and missing teeth are also more likely to show signs of declining brain health.
That declining brain health could affect memory and the ability to think clearly and function in life.
"Oral health is a quite easy to modify risk factor. It's one of the easiest. We just have to take better care of our oral health and it's not very costly or complicated," said study co-author Dr. Cyprien Rivier, a postdoctoral fellow in neurology at Yale School of Medicine.
The study doesn't demonstrate that dental hygiene actually improves brain health, but this is an area worthy of more research, said Dr. Joseph Broderick, a professor at the University of Cincinnati's Department of Neurology and Rehabilitation Medicine, and volunteer expert for the American Stroke Association.
Risk factors like smoking and diabetes play a larger role in poor oral health than genetic markers, Broderick noted in a stroke association news release. He was not involved in the research.
Rivier's team analyzed the potential link between oral health and brain health using data from the U.K. Biobank. The study included 40,000 adults without stroke history who were assessed between 2014 and 2021.
Each participant was screened for 105 genetic variants that can predispose someone to dental issues. The investigators also looked at MRI images of the participants' brains, scanning them for damage in the white matter, white matter hyperintensities and microstructural damage.
Brain white matter damage could impair memory, balance and mobility, the researchers noted. Microstructural damage would show up as changes to the fine architecture of the brain.
The study found that people with a tendency for cavities, missing teeth and dentures had a 24% increase in the amount of white matter hyperintensities.
They also had a 43% change in microstructural damage scores visible on their MRIs.
White matter hyperintensities typically accumulate silently over decades and have been strongly correlated with future stroke risk and future dementia risk, noted Dr. Shyam Prabhakaran, a professor of neurology at the University of Chicago School of Medicine. He was not involved in this study.
The research "starts to really move the dial towards earlier identifying of those that have poor oral health and then thinking about the public health implications of how do we treat people with that oral health earlier so that we can hopefully modify that and improve oral health," Prabhakaran said.
The idea is that would potentially lead to less change in the brain and then less stroke and dementia in the more distant future, he said.
As for the link between the mouth and brain health, it's possible that poor oral health creates low-grade inflammation in the body that then affects the lining of the blood vessels, Prabhakaran said. This may lead to cholesterol plaque buildup or micro clots.
Prabhakaran noted that some good research has been done on the impact of infections, including dental infections causing changes in the arteries.
"Something as simple as taking care of your teeth, brushing your teeth, going to dentists with the frequency that's recommended, those types of activities are well worth it. They're more than just cosmetic," Prabhakaran said.
Stroke is the fifth leading cause of death in the United States, according to the American Stroke Association. And about 3 in 5 people will develop brain disease during their lifetime, according to the association.
Rivier said the study results would need to be replicated in a randomized controlled trial before doctors could give specific recommendations. But, of course, there's no harm in suggesting everyone should take care of their teeth.
"It just adds another layer of incentive," Rivier said.
Study limitations include that those in the U.K. Biobank are mostly white people of European ancestry. More research needs to be done in diverse groups, the authors acknowledged.
The findings will be presented virtually and in Dallas at the American Stroke Association's international conference, Feb. 8-10. Findings presented at medical meetings are considered preliminary until published in a peer-reviewed journal.
The U.S. Centers for Disease Control and Prevention has more on dental health.
SOURCES: Cyprien Rivier, MD, MSc, postdoctoral fellow, neurology, Yale School of Medicine, New Haven, Conn.; Shyam Prabhakaran, MD, MS, professor and chair, Department of Neurology, University of Chicago School of Medicine; Joseph Broderick, MD, professor, University of Cincinnati, Department of Neurology and Rehabilitation Medicine, and director, University of Cincinnati Gardner Neuroscience Institute, Ohio; American Stroke Association International Stroke Conference, Feb. 8-10, 2023, Dallas