Take a moment to think about the distance between your teeth and your brain.

Once you recognize just how close they are, it’s a lot easier to see how dental conditions could affect the health of your brain. Bacteria and other toxins from the mouth don’t have that far to travel. And when they do travel, they can have quite an impact.

Gum Disease & the Incredible Shrinking Brain

One of the newest studies on this relationship appeared in the journal Neurology right after Independence Day.

One hundred seventy two older adults with no memory problems took part. At the start of the study, each had a dental exam, memory test, and brain scan to measure the volume of their hippocampus. This is a part of the brain that plays a role in memory and is one of the first regions that’s damaged when Alzheimer’s disease sets in.

Four years later, all these procedures were repeated.

The research team found that the number of teeth and the degree of gum disease was linked to the left hippocampus. For those with fewer teeth and mild gum disease, Its rate of shrinkage was faster. The rate was also faster for those with more teeth and severe gum disease.

After adjusting for age, researchers found that for people with mild gum disease, the increase in the rate of brain shrinkage due to one less tooth was equivalent to nearly one year of brain aging. Conversely, for people with severe gum disease the increase in brain shrinkage due to one more tooth was equivalent to 1.3 years of brain aging.

“These results highlight the importance of preserving the health of the teeth and not just retaining the teeth,” [study author Satoshi] Yamaguchi said. “The findings suggest that retaining teeth with severe gum disease is associated with brain atrophy. Controlling the progression of gum disease through regular dental visits is crucial, and teeth with severe gum disease may need to be extracted and replaced with appropriate prosthetic devices.” [emphasis added]

Biocompatible zirconia implants are a great option for replacing teeth lost to gum disease.

When Oral Bacteria Go After the Brain

Other research has focused on specific oral pathogens and their potential role in cognitive decline. A study from last summer, for instance, considered a species of bacteria known as F. nucleatum, which is abundant in the mouth and plays a key role in periodontal disease.

The research team first cultured cells in a lab to show that F. nucleatum caused abnormal growth of microglial cells. These are immunity cells in the brain and spinal cord that help remove infection from the brain. The presence of the oral bacteria also triggered an inflammatory response in them.

The researchers then used F. nucleatum to induce periodontitis in mice and looked for effects on their brains. (Periodontitis is the advanced form of gum disease in which tissue damage occurs.) Compared to control mice, the mice with periodontitis showed increased cognitive impairment, as well as higher levels of amyloid plaques and Tau protein. Both of those are indicators of Alzheimer’s disease. The same changes in microglial cell growth and inflammation were also observed.

Yet other research has found a different periodontal pathogen – P. gingivalis – in the brains of Alzheimer’s patients. What’s more,

Microbiome analyses of saliva samples or oral biofilms showed a decreased microbial diversity and a different composition in Alzheimer disease compared to cognitively healthy subjects. Many in-vitro and animal studies underline the potential of P gingivalis to induce Alzheimer disease-related alterations. In animal models, recurring applications of P gingivalis or its components increased pro-inflammatory mediators and β-amyloid in the brain and deteriorated the animals’ cognitive performance.

Keeping Your Brain Healthy by Keeping Your Mouth Healthy

A common denominator here is inflammation, which is the body’s natural response to infection or injury. It plays a crucial role in the immune system’s defense mechanisms.

Trouble comes when that inflammation is chronic, as is the case with gum disease. The persistent inflammation not only raises the risk of cognitive decline. It can raise your risk of stroke, as well. In fact, people with gum disease are roughly twice as likely to have a stroke compared to those with healthy mouths.

One of the best things you can do to change this? Shift to an anti-inflammatory diet. Multiple studies have shown, in fact, that even if you make no changes to your oral hygiene routine, quitting sugar and refined carbs while increasing your intake of omega-3s, fiber, and antioxidants can significantly improve the health of the gums.

Improving your oral hygiene routine can give you an additional boost, as well. For most people, that means getting consistent with their interdental cleaning, whether that’s with dental floss, a water flosser, interdental brushes, or some combination of these. If you’re only brushing, you’re only cleaning about 60% of your total tooth surfaces. Interdental cleaning is required to clean that last 40%.

If you have advanced gum disease, more frequent professional cleanings are also advised, in which we clean thoroughly below the gum line with high-tech tools such as our ultrasonic scaler, dental, and ozone, giving you a clean that you just can’t achieve at home.

Taking good care of your teeth and gums is taking good care of your brain.