Does gum disease play a key role in the development of Alzheimer's disease?
Scientists believe that this may be the case after their study has found further evidence of the association between bacteria in a common type of gum disease and those with dementia.
Researchers say their findings provide hope for a new way to fight the disease for which there is no cure and no effective treatment.
But does that mean that people should worry more about their oral health?
What did the researchers find?
Scientists studied brain tissue, cerebrospinal fluid and saliva from dead and living patients with diagnosed and suspected Alzheimer's disease.
Their study, published in the journal Science Advances, found bacteria associated with chronic gum disease Porphyromonas gingivalis in the brain of Alzheimer's patients.
Tests on mice confirmed that bacteria could enter the brain from the mouth and showed off the toxic protein they excrete (called gingipain) and destroyed brain neurons.
The bacteria also increased the production of amyloid beta, a component of amyloid plaques commonly associated with Alzheimer's.
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Subsequently, the scientists tested drugs in mice that were supposed to block the toxic proteins, and found that they could stop the degeneration in the brain.
The authors of the study concluded: "The results of this study demonstrate that Porphyromonas gingivalis and gingipain in the brain play a central role in the pathogenesis [development] of AD [Alzheimer̵
The team has now developed a new drug that it hopes will form the basis for treating humans and plans to test it in people with mild to moderate Al. # 39; s, in a clinical trial later this year.
What other scientists say about the study?
Scientists who were not involved in the research said it added that it was the evidence for the study's link between gum disease and dementia, the generic term for brain disorders that include Alzheimer's.
However, it is still unclear whether chewing gum bacteria are driving the development of Alzheimer's disease.
People with Alzheimer's disease are more susceptible to infections in their brain, so it may be that the bacteria of the gum disease and the toxic proteins they excrete are a byproduct of Alzheimer's and not a cause.
It has also been warned that the drug tests have taken place in mice.
Prof. Tara Spiers-Jones of the University of Edinburgh's Dementia Research Institute said it was "good news" that the study provided evidence that these drugs could affect Alzheimer's-related proteins.
"However, we will have to wait for the larger clinical trial to see if it benefits people with Alzheimer's disease," she said.
What were the earlier evidences?
Studies had previously linked chewing gum disease and dementia.
A Taiwanese study found that people with 10-year or longer history of chronic periodontitis (CP) had 70% more cases of Alzheimer's disease than those without disease.
Another study found that people with mild to moderate Alzheimer's disease who had suffered from gum disease had a decline compared to those with a faster cognitive decline.
The researchers of this new study say that one explanation for the association is that bacteria from gum disease may be accessing the brain by infecting the cells of the immune system or spreading through cranial nerves through the head and jaw.
But, alternatively, Alzheimer's patients may have poorer oral hygiene, perhaps because they are less able to look after teeth and gums because of their condition.
Where is that for us? 19659009] Charity The Alzheimer's Society responded to this study, saying that the research in which it had been involved had not established that gum disease was a major risk factor for Alzheimer's.
And Alzheimer's Research UK said the presence of a single type of bacteria is "extremely unlikely" to be the only cause of the condition. "
But given the condition of teeth and gums is important anyway for the condition General health is, said Professor Clive Ballard from the University of Exeter, that the study should perceive oral health as "very high priority for public health, especially in the elderly."
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