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Can periodontitis affect your brain?

Periodontitis, also known as gum disease, is a serious infection of the gums and tissues surrounding the teeth. In recent years, research has suggested that periodontitis may be linked to other health issues, including problems with the brain. Here we’ll explore the connection between periodontitis and brain health.

What is periodontitis?

Periodontitis occurs when plaque, a sticky film containing bacteria, builds up on the teeth. The bacteria in plaque produce toxins that inflame the gums. This inflammation causes the gums to pull away from the teeth, forming pockets that become infected. The bacteria can eventually spread down to the bone and destroy the tissues holding the teeth in place. Over time, severe gum disease can lead to tooth loss.

The early stage of gum disease is gingivitis. At this point, the gums are inflamed but the infection hasn’t damaged the tissues or bone. Regular brushing and flossing can typically reverse gingivitis. However, if left untreated, gingivitis can advance to periodontitis.

Periodontitis affects almost half of adults over age 30 in the United States. Risk factors include smoking, diabetes, genetic susceptibility, stress, poor nutrition, hormonal changes, and certain medications.

How periodontitis relates to inflammation

Inflammation appears to be the link between periodontitis and conditions such as heart disease and diabetes. Periodontitis causes chronic inflammation, which over time can spread and trigger inflammation throughout the body. This widespread inflammation can then contribute to other diseases.

Inflammation is an important part of the body’s immune response. It helps defend against harmful invaders. However, chronic low-level inflammation can gradually damage tissues and organs. Many researchers now believe chronic inflammation is an underlying cause of various complex conditions.

The inflammation-Alzheimer’s disease connection

Alzheimer’s disease is characterized by progressive memory loss and cognitive decline. It’s caused by the formation of plaques and tangles in the brain. These disrupt communication between brain cells and lead to cell death.

Growing evidence suggests chronic inflammation is a major driver of Alzheimer’s disease. It’s thought to accelerate the buildup of plaques and tangles in the brain. Studies have found higher levels of inflammatory markers in the brains and blood of people with Alzheimer’s.

Since periodontitis causes persistent low-grade inflammation throughout the body, researchers have been investigating if it could influence Alzheimer’s disease progression. The results so far have been mixed, but suggest a potential link.

Major studies on the periodontitis-Alzheimer’s link

Here is a summary of key findings from studies analyzing if gum disease is connected to Alzheimer’s disease:

  • A 2020 study followed nearly 100 older adults for over a decade. It found that those with periodontitis at the start were six times more likely to develop Alzheimer’s disease than those without periodontitis. They also experienced a more rapid rate of cognitive decline.
  • Another study tracked cognitive function in about 5,500 older adults. Over 20 years of follow-up, people with periodontitis performed worse on cognitive tests than those without gum disease. They also had a 1.7 times higher risk of developing Alzheimer’s.
  • On the other hand, a 2022 study did not find an association between periodontitis and increased incidence of Alzheimer’s disease. However, people with periodontitis did progress to Alzheimer’s at a younger age.
  • Multiple studies have detected bacteria involved in gum infections, such as P. gingivalis and A. actinomycetemcomitans, in the brains of people with Alzheimer’s. This suggests the bacteria can enter the brain and potentially contribute to neuroinflammation.

Overall, there appears to be a link between periodontitis and cognitive impairment. But more research is needed to confirm gum disease can directly cause or exacerbate Alzheimer’s disease.

Potential mechanisms

There are a few leading theories on how periodontitis could impact the brain and raise Alzheimer’s risk:

  • Bacteria Migration: As mentioned, bacteria involved in gum disease have been found in Alzheimer’s patients’ brains post-mortem. One hypothesis is that once periodontitis allows bacteria to penetrate deep below the gums, the bacteria can then travel to the brain via blood vessels or nerves.
  • Inflammation: Periodontitis triggers chronic low-level inflammation throughout the body. This systemic inflammation may then hasten plaque buildup and tangle formation in the Alzheimer’s brain.
  • Immune Response: Periodontitis may cause overactivation of immune cells called monocytes/macrophages. High levels of these cells are also found in Alzheimer’s brains. The activated immune cells could damage the brain while trying to eliminate bacteria.

More research is underway to understand exactly how periodontitis could contribute to changes in the Alzheimer’s brain. Currently, it seems that inflammation is likely the main mediator.

Can gum disease affect cognition in other ways?

In addition to Alzheimer’s disease, a few studies suggest periodontitis may be associated with faster cognitive decline and poorer cognitive function. However, more research is needed.

One study followed over 460 middle-aged adults without dementia. Those with periodontitis performed worse on cognitive testing after two years compared to those without gum disease. MRI scans also showed greater brain tissue loss in the periodontitis group.

Another study found that older adults with periodontitis scored lower on tests of delayed memory and calculation skills compared to those without gum disease.

Overall, current evidence indicates periodontitis could exacerbate cognitive changes that occur with normal aging. But more studies are needed to understand the nature of this relationship.

Can treating periodontitis help the brain?

A few small studies provide early clues that treating severe gum disease may benefit the brain:

  • One study followed 15 patients with mild to moderate Alzheimer’s disease and severe periodontitis. After undergoing specialized gum treatment, they showed improvements in cognitive scores at 3 and 6 months.
  • Another pilot study looked at 47 patients with mild cognitive impairment or mild Alzheimer’s disease. In those who received a thorough dental cleaning, cognitive scores significantly improved at 6 months compared to the control group.

These preliminary results suggest reducing periodontal inflammation could potentially aid brain function. However, large controlled studies are needed to confirm if gum therapy can truly improve cognition or slow neurodegeneration.

Steps to reduce your risk

While much remains unknown about the periodontitis-Alzheimer’s link, good oral health habits can help protect your gums and avoid tooth loss. To minimize your risk of periodontitis:

  • Brush teeth twice daily for 2 minutes, and floss once per day
  • See a dentist regularly for cleanings and check-ups
  • Don’t smoke or use smokeless tobacco products
  • Manage chronic conditions like diabetes that increase gum disease risk
  • Eat a balanced diet low in sugar and high in antioxidants
  • Limit alcohol to moderate amounts
  • Reduce stress levels through relaxation techniques

Prioritizing dental care and gum health won’t guarantee you’ll never deal with Alzheimer’s or dementia. However, controlling periodontitis may help lower your odds and support healthy aging.

Key takeaways

  • Periodontitis causes inflammation that could accelerate Alzheimer’s disease progression. However, the relationship is not fully clear yet.
  • Bacteria involved in gum infections have been detected in the brains of Alzheimer’s patients. Chronic inflammation may also contribute to Alzheimer’s brain changes.
  • Some studies associate periodontitis with faster cognitive decline and worse cognition. More research is needed.
  • Early research suggests gum disease treatment may improve cognitive function in people with impairment. Larger studies are needed.
  • Good oral care can help prevent periodontitis and support overall health as you age.


At this time, there’s not enough evidence to confirm severe gum disease directly causes or worsens Alzheimer’s disease. But multiple studies have uncovered links between periodontitis, chronic inflammation, and poorer brain health.

It’s possible that controlling oral inflammation could support cognitive function as we age. But more research is required to demonstrate treating periodontitis can prevent or slow down neurodegeneration.

Regardless, it’s smart to take care of your gums and teeth. Practicing excellent oral hygiene helps maintain your quality of life as you get older by preventing tooth loss. It also reduces harmful inflammation that could impact your whole body, including your brain.