The Mouth–Brain Connection: How Better Oral Health May Help Protect Cognitive Function

For years, oral health has been viewed primarily as a matter of protecting teeth and gums. But a growing body of research suggests that what happens in the mouth may also be connected to what happens in the brain.

Recent research is drawing increasing attention to the relationship between oral health, periodontal disease, tooth loss, and cognitive decline. While scientists are still working to determine whether poor oral health directly contributes to dementia, the evidence is strong enough to make oral care an important part of healthy aging.

Your Mouth and Brain May Be More Connected Than We Think

The mouth is home to hundreds of species of bacteria. When plaque and periodontal inflammation are not adequately controlled, harmful bacteria and inflammatory molecules can persist in the oral tissues.

Periodontal disease is a chronic inflammatory condition. Inflammation in the mouth can contribute to systemic inflammatory activity, which is one of several pathways researchers are investigating in connection with cognitive health.

A 2026 study from the Baltimore Longitudinal Study of Aging followed 756 adults who were free of cognitive impairment at the beginning of the study. Researchers found that greater tooth loss was associated with faster decline across several cognitive domains, including memory, attention, executive function, language, and visuospatial ability. Dental plaque was also associated with declines in memory and executive function.

These findings do not prove that periodontal disease or tooth loss causes dementia. However, they reinforce the importance of taking oral health seriously as we age.

Toothbrushing May Be More Important Than We Realize

A systematic review and meta-analysis examining oral hygiene behaviors found an association between toothbrushing and slower cognitive decline. The review included eight studies involving more than 261,000 participants and found that toothbrushing was associated with better global cognitive outcomes over time.

Interestingly, the evidence suggests that maintaining oral hygiene can remain important even when a person is already experiencing cognitive impairment.

For individuals with dementia, however, oral hygiene can become increasingly difficult. Forgetfulness, difficulty following routines, reduced dexterity, and lack of awareness of oral problems may all interfere with daily brushing and professional dental care.

This is why caregivers and family members can play an important role in maintaining oral hygiene.

Periodontal Health Deserves Special Attention

Periodontal disease is not simply a problem of bleeding gums. Advanced periodontal disease can lead to destruction of the tissues and bone supporting the teeth and ultimately tooth loss.

Research has increasingly explored whether chronic periodontal inflammation may be associated with cognitive impairment. A systematic review of oral-health interventions in people with dementia concluded that oral hygiene care may have a positive role in maintaining cognition, although the evidence remains limited and additional research is needed.

That distinction is important: we should not tell patients that treating gum disease will prevent Alzheimer’s disease or dementia. Instead, we should recognize oral health as one potentially modifiable component of overall healthy aging.

Protecting the Teeth May Also Protect Quality of Life

There is another important connection: chewing ability.

Maintaining a functional dentition allows people to chew comfortably and maintain a more varied diet. A 2025 longitudinal study found that older adults with better oral health and good chewing ability had a lower risk of developing cognitive impairment or dementia during follow-up.

Preserving natural teeth, treating periodontal disease, replacing teeth when appropriate, and maintaining good oral hygiene may therefore contribute to overall health, nutrition, independence, and quality of life.

Don’t Wait Until Oral Problems Become Severe

As people age, routine dental and periodontal examinations become increasingly important.

A comprehensive prevention strategy should include:

• Brushing thoroughly twice a day
• Cleaning between the teeth every day
• Controlling dental plaque
• Maintaining healthy periodontal tissues
• Regular professional dental examinations
• Treating periodontal disease early
• Monitoring for tooth mobility and tooth loss
• Helping older adults who have difficulty maintaining their own oral hygiene
• Maintaining the ability to chew comfortably

For patients with cognitive impairment, caregivers should pay particular attention to changes in oral hygiene, bleeding gums, bad breath, loose teeth, difficulty chewing, or changes in eating habits.

Could Protecting Your Mouth Help Protect Your Brain?

We don’t have enough evidence to say that good oral care prevents dementia. But the relationship between oral health and cognitive health is becoming increasingly difficult to ignore.

The newest research suggests that tooth loss, dental plaque, periodontal symptoms, oral hygiene, and chewing ability may all be connected with cognitive health in older adults.

That gives us another reason to think about periodontal care differently.

Taking care of your gums isn’t only about keeping your smile healthy. It may also be an important part of protecting your overall health and maintaining independence as you age.

A healthy mouth may be one more piece of the healthy-aging puzzle.

About the Author
Dr. Jin Eslami, DDS, MS, is a board-certified periodontist with over 30 years of experience in periodontal disease treatment, dental implants, and advanced bone regeneration. Based in Rancho Santa Margarita, she specializes in complex cases involving severe gum disease and full-arch implant rehabilitation. Dr. Eslami is a strong advocate for the connection between oral health and systemic conditions, including cardiovascular disease and cancer.

To learn more or schedule a consultation, contact Dr. Eslami’s office for expert periodontal and implant care.
Orange County Oral Surgery & Periodontics
Phone: 949-888-0332
Website: https://www.ocosperio.com/