Brushing your teeth may not just be about keeping good dental hygiene. A new study, published in the journal PLOS ONE, has shown that gum disease may be linked to a greater rate of cognitive decline in those suffering from Alzheimer’s disease.
At first, it would seem strange that this neurodegenerative disorder and gum disease would be in some way connected. Alzheimer’s is a complex, debilitating condition that gradually destroys the brain's neural cells (neurons) over time, leading to hallucinations, paranoia, aggressiveness, hampered mobility, linguistic difficulty, dementia, and significant memory recall problems.
Gum disease is a relatively common condition that is caused by an accumulation of bacteria on the teeth. Initially this causes gingivitis, where gums swell up and begin to bleed. Eventually, if left untreated, this can progress to become periodontitis, which can cause severe damage to the jaw and the tissues that keep teeth in place.
As this new study demonstrates, these two seemingly unrelated afflictions do share something in common: inflammation. Although inflammation is a common immune response to infectious diseases, a build-up of immune cells in the brain called microglia, which are also linked to inflammation, are thought to be drivers of Alzheimer’s.
For the study, 59 people classed as having mild to moderate dementia – of which Alzheimer’s is the leading cause – were cognitively examined and assessed, before having their oral health looked into by a dental hygienist. Blood samples were also used to investigate the level of inflammatory “markers” in the blood – proteins and other components that are indicators of inflammation in the body.
Is gum disease-related inflammation really linked to worsening dementia? SpeedKings/Shutterstock
Of those individuals, 22 were found to have considerable gum disease, whereas the rest showed no major signs of it. Six months later, after a few dropouts, 52 of the original 59 were followed up and given the same cognitive and oral examinations. The results seemed to suggest that the presence of periodontitis was associated with an incredible 600 percent increase in the rate of cognitive decline.
“In just six months you could see the patients going downhill – it's really quite scary,” Dr. Mark Ide, a reader in periodontology at King's College London and the lead author of the study, said to BBC News.
Higher levels of antibodies related to the occurrence of periodontal bacteria are associated with higher levels of inflammatory markers. These markers have been linked to a greater rate of cognitive decline in relation to Alzheimer’s disease, and this study implies that the inflammation caused during gum disease is contributing to the progression of the neurodegenerative condition.
It’s therefore possible that maintaining good dental hygiene may slow the progression of dementia and Alzheimer’s. However, this small study does not conclusively prove this correlation, and these results could be interpreted quite differently: A progressing Alzheimer’s condition could be causing severe gum disease, rather than the other way around. Future research will certainly require a larger number of participants.