Alzheimer’s, dental health links grow with new research

A new study out of the United Kingdom builds on previous research that people who don’t take care of their teeth or who have gum disease may be more likely to develop dementia. The new research, however, specifically suggests a possible link between oral health and Alzheimer’s disease.

When researchers from the University of Central Lancashire (UCLan) School of Medicine and Dentistry examined brain samples from 20 deceased people—10 who’d had dementia and 10 who had not—they found evidence of Porphyromonas gingivalis in the former group. The bacterium is commonly associated with chronic gum disease.

“Whereas previous studies have indicated a link between dementia and other bacteria and viruses such as the Herpes simplex virus type I, this new research indicates a possible association between gum disease and individuals who may be susceptible to developing Alzheimer’s disease if exposed to the appropriate trigger,” said Stjohn Crean, PhD, dean of the school, in a press release issued by the Journal of Alzheimer’s Disease, which is publishing the findings. Crean led the research with Sim Singhrao, PhD, a senior research fellow at UCLan.

P. gingivalisbacteria originally enter the bloodstream especially after invasive dental treatment but also through activities such as eating, chewing and toothbrushing, the investigators said. When they reach the brain, the bacteria may result in immune system responses, causing brain cells to release chemicals that kill neurons, researchers added. Such actions, they said, could lead to the confusion and memory deterioration associated with Alzheimer’s disease.

Crean said that UCLan scientists are continuing to explore the link between Alzheimer’s disease and dental health, “but it remains to be proven whether poor dental hygiene can lead to dementia in healthy people, which obviously could have significant implications for the population as a whole. It is also likely that these bacteria could make the existing disease condition worse.”

These findings have additional implications for dementia care, because oral hygiene can be especially challenging to maintain in residents who have dementia. Caregivers often struggle to obtain cooperation from residents for toothbrushing, and the hands-on activity can result in accidental or deliberate biting.

Visits to the dentist may be more important than previously thought, Singhrao said. Researchers will try to determine whether a blood test, using P. gingivalis as a marker, can be developed to predict the development of Alzheimer’s disease in those thought to be at risk, she added.

Lois Bowers

Lois A. Bowers was senior editor of I Advance Senior Care / Long-Term Living from 2013-2015.