Gum disease tied to Alzheimer's risk

People with poor dental hygiene or gum disease may be at a higher risk of developing Alzheimer's disease, according to a new study.
Researchers at the University of Central Lancashire (UCLan) in UK studied brain samples from deceased dementia patients and found that they contained unusually high levels of Porphyromonas gingivalis, a type of bacteria which causes gum disease.
Although the bacteria live in the mouth, they can enter the bloodstream during eating, chewing, tooth brushing or dental surgery, and potentially reach the brain, experts said.
Inflammation caused by gum disease-related bacteria has already been linked to various health problems including diabetes, heart disease and stroke, 'The Telegraph' reported.

The arrival of the bug in the brain could cause the immune system to release chemicals which kill brain cells, causing the confusion and memory loss associated with Alzheimer's.
"We are working on the theory that when the brain is repeatedly exposed to bacteria and/or their debris from our gums, subsequent immune responses may lead to nerve cell death and possibly memory loss," Dr Sim Singhrao, one of the authors of the study, said.

"Our hypothesis is that this is a chronic assault. It is not happening overnight, it is a build-up over years. But all we have shown so far is that bacteria from the gum region get into the brain. We haven't proven that they cause Alzheimer's disease," said Professor StJohn Crean, dean of the school of medicine and dentistry at UCLan.

Earlier research has linked dementia to other bacteria and viruses, such as the Herpes simplex virus type 1, but the new study is the first to identify Porphyromonas gingivalis in the brains of dementia patients.
"We don't know whether the presence of these bacteria in the brain contributes to the disease and further research will be needed to investigate this," said Dr Simon Ridley, of Alzheimer's Research UK.
The study was published in the Journal of Alzheimer's Disease.