Did you know that a large study has linked gum disease with dementia?
The mouth is home to about 700 species of bacteria, including those that can cause periodontal (gum) disease. The evidence of a connection between inflammation and neurodegenerative diseases of the central nervous system is becoming more apparent. A recent analysis led by National Institute on Aging scientists suggests that bacteria that cause gum disease are also associated with the development of Alzheimer’s disease and related dementias, especially vascular dementia. The results were reported in the Journal of Alzheimer’s Disease (July 2020).
Gum disease results from infection of the oral tissues holding teeth in place. Bleeding gums, loose teeth, and even tooth loss are the main effects of this disease. Bacteria and the inflammatory molecules they make, can travel from infections in the mouth through the bloodstream to the brain. Previous lab studies have suggested that this is one mechanism influencing the cascade of events that leads to dementia, but large studies with people have not been conducted to confirm this relationship.
The scientists in this study compared different age groups at baseline, with up to 26 years of follow-up, for more than 6,000 participants. The team analyzed antibodies against 19 oral bacteria for an association with the diagnosis of Alzheimer’s, diagnosis of any kind of dementia, and death from Alzheimer’s. Of these 19, Porphyromonas gingivalis is the most common culprit of gum disease. In fact, a recent study suggests that plaques of beta-amyloid protein, a major hallmark of Alzheimer’s disease, may be produced as a response to this infection.
The analysis revealed that older adults with signs of gum disease and mouth infections at baseline were more likely to develop Alzheimer’s during the study period. Among those 65 years or older, both Alzheimer’s diagnoses and deaths were associated with antibodies against the oral bacterium P. gingivalis, which can cluster with other bacteria such as Campylobacter rectus and Prevotella melaninogenica to further increase those risks. This study provides evidence for an association between periodontal pathogens and Alzheimer's disease, which was stronger for older adults. Future studies can determine if treating infections with P. gingivalis can reduce the development or symptoms of dementia.
Reference: Beydoun M, et al. Clinical and bacterial markers of periodontitis and their association with incident all-cause and Alzheimer's disease dementia in a large national survey. Journal of Alzheimer's Disease. 2020;75(1):157-172. doi: 10.3233/JAD-200064.