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The Link Between Periodontal Disease and Brain Diseases

There is growing evidence of a connection between inflammation in the body and diseases of the brain such as Alzheimer’s, Parkinson’s disease, ALS, and dementia*. There have been recent clinical and epidemiological studies investigating the possible links between periodontal bacteria (that elicit inflammation) and the onset and progression of neurodegenerative diseases.

Periodontal disease is a complex, chronic disease characterized by a bacterial etiology and an inflammatory response. Dental plaque is harbored by many species of bacteria, in an attempt to combat this bacteria, the human body signals an immune response. Many times, however, the immune system fails to remove all of the “bad” bacteria. The inflammation response tends to become chronic. Bleeding gums, inflammation, swelling are all signs of this response to bacteria. Over time gingivitis leads to periodontitis which includes bone loss around the teeth.

Neurodegenerative diseases affect 50% of elderly patients. Age and heredity are two key risk factors for these diseases, another is the presence of amyloid proteins. This protein may be caused by inflammation produced by periodontitis.

So what’s in common?

Two periodontitis-related mechanisms related to brain diseases are inflammation and bacteria.

In the process of inflammation, signal proteins are released into the blood. These proteins reach the brain via systemic circulation and by following the nervous system. These proteins can amplify a reaction favoring brain disease progression. The bacteria themselves that cause periodontitis have been found to invade the central nervous system (the brain), some cause the creation of amyloid. There is a statistically significant relationship between the main bacteria involved with periodontal disease, P. gingivalis, and dementia.

Clinical evidence showing a direct connection between periodontitis and brain diseases has not been obtained. Nevertheless, there is indirect evidence. It is recommended that a preventative approach related to known risk factors of periodontal disease (poor oral hygiene, smoking, diabetes) be addressed. A treatment that helps to eradicate the bacteria that cause periodontal disease would be a sound approach. Treatment of periodontal disease could mean a more efficient management of the patient and consequently a better quality of life.

*The Role of Peridontitis and Periodontal Bacteria in the Onset and Progression of Alzheimer’s Disease: A Systematic Review

Dioguardi et al J. Clin. Med 2020, 9(2), 495