Reality check: Can flossing actually help prevent Alzheimer’s disease?
Bleeding gums and sensitive teeth may be painful, but new research has linked gum disease to something bigger: Alzheimer’s disease.
A new study, published in the journal Science Advances, found that the bacteria that causes gum disease was present in the brains of people with Alzheimer’s.
Unlike past studies, the research is asserting that Porphyromonas gingivalis — the key bacteria in chronic gum disease — may contribute to a person developing the condition.
The research, conducted by private pharmaceutical company Cortexyme, Inc., looked at over 50 brains of people who had the disease, and those who did not. They found that 90 per cent of folks with Alzheimer’s also had toxic enzymes produced by P. gingivalis called gingipains.
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The brains with more gingipains had higher levels of tau and ubiquitin, which are proteins linked to Alzheimer’s. In brain samples of dementia-free adults, researchers found lower levels of gingipains.
Dr. Steve Dominy, the study’s lead author and co-founder of Cortexyme, went so far as to tell Newsweek that the bacteria related to gum disease is the “main cause of Alzheimer’s disease, and the gingipains are the main drivers of Alzheimer’s disease pathology.”
Based on their findings, Cortexyme researchers said a drug targeting gingipain inhibitors could be valuable for treating the degenerative condition.
While Dominy and his team are confident in the connection between gum disease and dementia, others are less certain.
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According to Dr. David Stevenson, the president of the Ontario Dental Association, the new research shows “there’s a relationship [between gum disease and Alzheimer’s], but the relationship does not necessarily mean cause and effect.”
“With most diseases of any kind, including gum disease, there are multiple different factors involved and multiple different organisms,” he said to Global News.
“The fact that they have isolated a specific bacteria that’s quite common in the brains of people with Alzheimer’s, I think that’s cause for hope. It’s not necessarily cause for skepticism, but it’s cause for hope and caution, and for further studies to try to confirm just what that relationship is.”
Previous studies that looked at the relationship between oral health and brain health drew mixed results.
A 2016 study conducted by researchers from the U.K.’s University of Southampton found that having gum disease is tied to faster cognitive decline in adults with Alzheimer’s. While the research found a link, it wasn’t clear if gum disease causes cognitive decline.
According to one theory based on those findings, cognitive impairment leads to adverse oral health due to inattention to routine oral hygiene and care, said Dr. James M. Noble of the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain at Colombia University Medical Center in New York City, who was not part of the study.
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“The second, and the one I’m most intrigued by, is whether or not periodontal disease has an influence on cognitive outcomes of aging, either as an independent risk factor for [new-onset] cognitive impairment including Alzheimer’s disease, or more rapid decline once [Alzheimer’s disease] has been diagnosed, as was suggested by this study,” Noble told Reuters Health by email.
Another study also raised some questions about these findings.
Researchers out of Duke University’s School of Nursing looked at over 50 studies that looked at the relationship between oral health and cognitive problems in older adults.
Some studies found that markers of oral health, like the number of teeth and presence of gum disease, were tied to the rate of cognitive decline or dementia risk. But the links weren’t stable in every study, as some studies found no link between oral and brain health.
A 2017 study out of Taiwan found that chronic gum inflammation, known as periodontitis, is associated with an increased risk of developing Alzheimer’s disease.
While they found no overall link between periodontitis and Alzheimer’s, researchers did conclude that people who had the chronic gum inflammation for 10 or more years were 70 per cent more likely than people without periodontitis to develop Alzheimer’s.
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So what does this all mean? Stevenson said what dentists know for certain is that good oral health contributes to better overall health, period.
“We’ve certainly been having conversations in the dental community around gum disease and periodontal disease… and how they can relate to other diseases in the body, in particular, cardiovascular disease and diabetes,” he said.
“We use our teeth for so many different reasons: to chew, to nourish ourselves, to smile, to speak properly. There are so many different benefits to keeping our teeth as long as we can — and keeping our teeth healthy.”
With files from Reuters
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