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Can periodontal disease be linked to Alzheimer’s? Recent news reports have suggested that an infection initiated by a bacterium found in the oral cavity could be a predisposing factor or an initiator of Alzheimer’s disease. The Bulletin takes a closer look at the evidence By Margaret Galvin
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lzheimer’s disease (AD) is the most common type of dementia, causing problems with memory, thinking, and behaviour. Dementia affects approximately 160 000 Australians, with Alzheimer’s disease accounting for 50-75% of dementia cases. The most important risk factor of Alzheimer’s disease is the increase of age. Other predisposing factors thought to contribute to Alzheimer’s include genetics, chromosomal factors, diet, and aluminium. As you may well know, periodontal disease is an inflammatory disease which affects the soft and hard structures that support the teeth, or as I tell my patients, it is a disease that destroys the structures that help hold your teeth in your head! Porphyromonas gingivalis (P. gingivalis), the pathogen which contributes to the pathogenesis of Chronic Periodontitis, has been found in the brains of deceased Alzheimer’s patients. Could it be that periodontal disease is also a predisposing factor or an initiator of Alzheimer’s disease?
The Science The following is what researchers have found through one particular scientific study – Ilievski, V. Zuchowska, PK. et al 2018:
n 10 mice in a study group were exposed orally to
P. gingivalis over 22 weeks and another 10 mice were in a control group n Brain tissue health was studied in both groups after 22 weeks n Significantly higher amounts of accumulated amyloid beta (peptides found in the plaques of brains affected by AD) was found in the study group n Increased brain inflammation and fewer intact neurons due to degeneration were also found in the study group n DNA of the bacteria was found in the brain tissue of the study group n Bacterial protein was noted inside their neurons
“ Researchers state their results strongly suggest that chronic oral infection of P. gingivalis can be an initiator of the development of neuropathology that is consistent with that characteristic of Alzheimer’s disease in humans”
