A New Study Shows Gum Disease May Cause Alzheimer's Disease
Alzheimer’s disease (AD) has long been studied as a disease of inflammation with very poor results using anti-inflammatory drugs, indicating there is more to the condition than just inflammation. Mechanistically, Alzheimer's is caused by the build-up of sticky amyloid plaques and mis-folded tau proteins in the brain, which break down communication between neurons and lead to memory loss, cognitive decline, and eventually death. (1) A 2016 editorial of 31 AD researchers refers to the many studies, mainly on humans, implicating specific microbes in the elderly brain in the etiology of AD, and urges a new focus on infectious agents as the cause. To quote, “We propose that infectious agents, including HSV1, Chlamydia pneumonia, and spirochetes, reach the CNS and remain there in latent form. These agents can undergo reactivation in the brain during aging, as the immune system declines, and during different types of stress (which similarly reactivate HSV1 in the periphery). The consequent neuronal damage— caused by direct viral action and by virus-induced inflammation— occurs recurrently, leading to (or acting as a cofactor for) progressive synaptic dysfunction, neuronal loss, and ultimately AD. Such damage includes the induction of Aβ which, initially, appears to be only a defense mechanism.” (2)
Nearly 50 million people have Alzheimer’s or related dementia worldwide, and only 1-in-4 people with Alzheimer’s disease have been diagnosed. Every 66 seconds someone in the United States develops Alzheimer’s. One-third of Americans over age 85 are afflicted with the illness. (3)
At the same time, two thirds of American adults aged 30 and over has periodontal disease, according to recent findings from the Centers for Disease Control and Prevention. 64% of adults aged 65 years and older had either moderate or severe periodontitis. (4)
A 2014 study published in the Journal of Alzheimer's Disease found P. Ginigivalis in the brain tissue of mice, contributing to neuronal injury. (5) In 2016 Mark Ide e.t al. found that gum disease was associated with an increase in cognitive decline in Alzheimer’s Disease. (6) A new study published in Science Advances by Stephen S. Dominy et. al. demonstrated that P. Gingivalis, the germ responsible for gum disease, is associated with the amyloid plaques in humans associated with Alzheimer’s disease. They were able to show that the bacteria were present in the brain. Specifically, the study identified major virulence factors known as gingipains secreted by the bacteria that are responsible for causing inflammation of the neurons of the brain. They found that inflammation in AD brains was significantly greater than in brains of non-AD control individuals, and it was related to the amount of gingipain antibodies present.
These findings bring us much closer to understanding that underlying gum disease is a factor in Alzheimer’s disease development and prognosis. In the same study, they were able to show that oral administration of small-molecule gingipain inhibitors blocks gingipain-induced neurodegeneration and significantly reduces P. gingivalis load in the mouse brain. In other words, there is a drug that blocks the bad effects of gingipains. This could be huge in treating and reversing the effects of Alzheimer’s disease.
In summary:
· Alzheimer’s disease and gum disease are extremely common
· Alzheimer’s disease and gum disease are often found together
· P. Gingivalis, the bacteria responsible for gum disease is found in the brains of Alzheimer’s disease sufferers
· P. Gingivalis produces destructive substances called gingipains
· Gingipain inhibitors can block gingipains in mice, showing promise as a treatment for Alzheimer’s disease in humans some day
Since there is such a strong link between gum disease and Alzheimer’s disease, it is imperative to visit your dentist regularly and treat any gum disease or gingivitis.