A study from July 2020 confirmed that gum disease is a risk for Alzheimer’s disease. This study was based on the third National Health and Nutrition Examination Surveys (NHANES III, 1988-1994). Researchers followed more than 6000 patients for up to 26 years. The degree of chronic gingivitis was determined by measuring gingival pocket depth. In addition, blood tests with antibody titers (immunoglobulin G) as bacterial markers were taken as well. The main bacterium responsible for Alzheimer’s disease was Porphyromonas gingivalis (P. gingivalis). But there were others as well, like Prevotella melaninogenica (P. melaninogenica) and Campylobacter rectus (C. rectus).
Other studies suggesting a connection of gum disease to Alzheimer’s disease
A review dated January 2019 described that gum disease could lead to Alzheimer’s disease. Porphyromonas gingivalis is a bacterium that is associated with chronic gum disease, called gingivitis. It occurs when you don’t brush and floss your teeth regularly. Researchers found P. gingivalis in the brains of deceased Alzheimer’s patients, but also in spinal fluid of living patients with Alzheimer’s disease. P. gingivalis bacteria produce toxic proteases called gingipains. These break down beta-amyloid protein in the brains of Alzheimer’s patients and transform the proteins into tangles.
Mouse experiments, which proved that gum disease is a risk for Alzheimer’s disease
Researchers wanted to find out whether P. gingivalis caused Alzheimer’s disease. They swabbed the gums of mice every other day for 6 weeks with cultured P. gingivalis. Later they detected the bacteria in the brains of the experimental mice. They also found dying neurons and above normal levels of beta-amyloid. In addition, they detected higher levels of gingipains and broken-down beta-amyloid protein in the form of tangles.
Trial of new drug in patients to inhibit formation of gingipains
Researchers from Cortexyme Inc. developed a new drug that inhibits the action of gingipains. In a phase I clinical trial they showed that patients tolerate this drug well. About 50% of people develop P. gingivalis in their gums. As a result they are at risk of developing chronic gingivitis and Alzheimer’s disease.
There is good evidence that beta-amyloid in the brain is necessary for normal brain function. Only, if there is too much beta-amyloid present, there is a potential for breakdown of beta-amyloid and degenerative brain disease like Alzheimer’s disease. Researchers found a bacterium, Porphyromonas gingivalis present in the gums of patients with chronic gingivitis. This results from not brushing and flossing your teeth regularly. The bacteria produce proteases, gingipains, which break down beta-amyloid into tangles. The process causes a neurodegenerative process, which ultimately leads to Alzheimer’s disease. Cortexyme Inc., a drug company from San Francisco developed a new drug that inhibits the action of gingipains. In a phase I clinical trial they showed that patients tolerate this drug well. But you do not have to wait until you need a drug.
If healthy people want to be on the safe side and reduce their risk for getting Alzheimer’s disease, Dr. Noble says: “The main conclusion we still have is: brush and floss.”