Trouble thinking? Better see the dentist

A man shows off his tattoo during a tattoo expo in Budapest November 30, 2008.

NEW YORK (Reuters) - Good oral care such as regular brushing, flossing and trips to the dentist, may help aging adults keep their thinking skills intact, according to a U.S. study.

Research has already established an association between poor oral health and heart disease, stroke and diabetes, as well as Alzheimer's disease.

But researchers from Columbia College of Physicians and Surgeons in New York found gum disease could also influence brain function through several mechanisms, such as causing inflammation throughout the body, a risk factor for loss of mental function.

The study based on adults aged 60 and older found those with the highest levels of the gum disease-causing pathogen Porphyromonas gingivalis were three times more likely to have trouble recalling a three-word sequence after a period of time.

The study, led by Dr. James Noble, also found that adults with the highest levels of this pathogen were two times more likely to fail three-digit reverse subtraction tests.

"Despite the association of periodontitis with stroke and shared risk factors between stroke and dementia, to our knowledge, no epidemiological studies have investigated periodontitis relative to cognition," the researchers wrote in their study.

"Although results presented here are preliminary and inconclusive, a growing body of evidence supports exploration of a possible association between poor oral health and incident dementia."

The study, reported in the Journal of Neurology, Neurosurgery, and Psychiatry, was based on more than 2,350 men and women who were tested for periodontitis and completed numerous thinking skills tests as part of a national survey.

Overall 5.7 percent of the adults had trouble completing certain memory tasks, 6.5 percent had impaired delayed recall, and 22.1 percent had trouble with serial subtractions.

But those with the levels of the pathogen were nearly three times more likely to struggle with the verbal memory tests, and twice as likely to fail on both delayed verbal recall and subtraction tests.

"Although our results are preliminary, they suggest that further exploration of relationships between oral health and cognition is warranted," they concluded.

(Reporting by Joene Hendry of Reuters Health, Editing by Belinda Goldsmith)