The Surprising Risk Factor for Dementia That Has Nothing to Do With Diet or Exercise

The health of your brain is one more reason to practice good oral hygiene, according to a growing body of research.

October 22, 2025

older woman holding flower in front of her face

A common refrain among neurologists is that embracing healthy habits for your body—like eating a variety of plants, getting quality sleep, and staying active—is good for your mind too. And based on an ever-growing body of research, the same thing applies to taking care of your teeth and gums: Keeping them thriving could have upstream benefits for your brain.

For a new study published in Neurology Open Access, an official journal of the American Academy of Neurology, researchers did dental exams and took brain scans of more than 1,100 people and found that those with gum disease had 56% higher odds of having a substantial number of white matter hyperintensities, or spots that reflect brain damage, than their peers with healthy gums. That’s a big deal because these brain changes (which become more common with age) have been tied to cognitive decline and dementia, as well as stroke and mobility issues, Souvik Sen, MD, MPH, study author and chair of the neurology department at the University of South Carolina School of Medicine, tells SELF.

And this isn’t the first research to suggest harboring dental issues ups your risk for brain trouble. Previous MRI studies have also shown that people with poor oral health are more likely to have a greater volume of white matter hyperintensities, and that having a higher extent of gum disease is connected to other brain features of dementia. Plus, big population studies have discovered that people with signs of gum disease (like tooth loss and gum swelling) are more likely to be diagnosed with Alzheimer’s or show symptoms of mild cognitive impairment than those without oral-health problems.

Of course, there’s a possible chicken-and-egg scenario; if you develop memory problems, you might be less likely to maintain your oral health, Panos Papapanou, DDS, PhD, a professor of dental medicine at Columbia University’s College of Dental Medicine, tells SELF. But generally “the pattern converges” in one direction, he says: More severe gum disease and teeth issues are linked with more concerning brain outcomes.

How poor oral health could bump up your dementia risk

You might think your teeth and gums are in their own little care silo—something to be dealt with at the dentist versus in a visit with your primary care doctor, for instance. But in reality, your mouth is a portal to the rest of your body, meaning that when something goes wrong within it, the effects can spread to other organs, including your brain.

One way that can happen is via bacteria, which exist in everyone’s mouth but accumulate differently in folks who develop gum disease, much like how the balance of microbes in your gut can get out of whack, Ryan T. Demmer, PhD, MPH, a professor of epidemiology at the University of Minnesota, tells SELF. A disruption in this healthy mix can lead to gum irritation and bleeding, which may allow some of the bacteria to enter the bloodstream, he says.

From there, the germs can hitch a ride throughout your body, and there’s some evidence that they may even pass across the blood-brain barrier (a shield of cells that typically keep bad stuff out of the brain), Natalie Jeong, DMD, the chair of the periodontology department at Tufts University School of Dental Medicine, tells SELF. Some of these microbes may be directly toxic and have the potential to interfere with cognitive function.

More broadly, these bacteria kick your immune system into overdrive, sparking the release of inflammatory chemicals that can also traverse your body. This inflammation is best known to cause a hardening of your blood vessels, which creates the blockages that trigger a heart attack or stroke, Dr. Sen explains. (It’s no wonder he and his team also found, in a different new study, that having gum disease and cavities is linked to an 86% increased risk of stroke—which can set you on a faster track to dementia too.) But at the same time, inflammation can also make it to your brain and cause the tiny vessels there to get brittle, Dr. Sen says, reducing blood flow and, in turn, triggering those spots of damage.

Some advice for keeping your teeth in good shape—and protecting your brain too

While some people may be genetically more likely to develop oral health issues than others, you also have a good deal of power to influence that outcome. You’ve heard it plenty of times before because it’s true: Brushing your teeth twice a day (for two minutes each time) and flossing daily, can help you prevent gum disease, as can going easy on sugary foods and avoiding smoking and smokeless tobacco.

Similarly, it’s important to go to the dentist twice a year if you have dental insurance or can afford to pay out-of-pocket (here’s a guide to caring for your teeth without insurance); in some areas, community health centers and dental schools may offer lower-cost options. This way, you can get the benefit of a professional cleaning and make sure there aren’t any early signs of gum or teeth problems that should be addressed, Dr. Demmer says. In fact, Dr. Sen’s study on gum disease and stroke also found that those who visited the dentist regularly were 81% less likely to have both cavities and gum disease.

You’ll also want to keep an eye out for symptoms of mild gum disease (a.k.a. gingivitis)—like gums that look swollen or bleed when you brush or floss—and communicate these to your dentist, Dr. Jeong says. It can be very easy to ignore these red flags because there often isn’t a lot of pain, she says, but bringing them up ensures you can get treatment while the condition is still generally reversible. (According to Dr. Jeong, some non-invasive options include deep cleaning or scaling to clear away some of the bacteria, as well as systemic or localized treatment with antibiotics.)

Though it can be tempting to brush off a little bleeding from your gums, particularly if it’s not hurting you, Dr. Papapanou suggests viewing it, instead, like bleeding anywhere else—you’d probably address it stat, and the same should apply here, especially given the ties that connect your mouth with the rest of your body. But again, even if you haven’t had any bleeding or other symptoms, you should still keep up with regular dental appointments, Dr. Sen emphasizes. The more proactively you care for your teeth, the better you’ll steer clear of gum disease and shield your brain from the potential ripple effects along the way.