A new study hints that good oral care — regular brushing and flossing and trips to the dentist — may help aging adults keep their thinking skills intact.
In a study, researchers found that adults aged 60 and older with the highest versus the lowest 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.
Dr. James M. Noble of Columbia College of Physicians and Surgeons in New York City and colleagues also found that adults with the highest levels of this pathogen were two times more likely to fail three-digit reverse subtraction tests.
The findings, reported in the Journal of Neurology, Neurosurgery, and Psychiatry this month, are based on more than 2300 men and women who were tested for periodontitis and completed numerous thinking skills tests as part of the National Health and Nutrition Examination Survey III conducted between 1991 and 1994.
Overall 5.7 percent of the adults had trouble completing certain memory tasks and 6.5 percent failed reverse subtraction tests. Participants with the highest (greater than 119 units) versus the lowest (57 units or lower) pathogen levels were most likely to do poorly in these tests.
Research has already established a strong association between poor oral health and heart disease, stroke and diabetes, as well as Alzheimer's disease. Gum disease could influence brain function through several mechanisms, the researchers note; for example, gum disease can cause inflammation throughout the body, a risk factor for loss of mental function.
In a related commentary, Dr. Robert Stewart, of King's College in London, United Kingdom, says this study adds to a "quietly accumulating" body of evidence tying oral and dental health with brain function.