More than five million senior citizens across the United States suffer from Alzheimer’s disease, and as more and more baby boomers turn 65, that number is expected to increase significantly. The staggering costs of caring for memory-impaired seniors who need assistance with daily living can strain the personal resources of families as well as the publicly financed Medicare system. Preventing, slowing, or stopping late-onset Alzheimer’s disease, estimated to affect one in three elderly Americans, has become a priority, prompting President Obama to boost research funding as part of a historic and ambitious plan, the National Alzheimer’s Project. Through observations of genes, proteins, and gum disease, these three Boston University researchers are at the forefront of efforts aimed at identifying risk factors and developing new pathways to therapeutic targets.
What does gum disease have to do with memory loss?
“We say, lose your teeth, lose your mind,” says Professor Raul I. Garcia, chair of the Department of Health Policy & Health Services at the Henry M. Goldman School of Dental Medicine. “Poor oral health can predict future cognitive decline.”
Cavities and gum disease, a chronic inflammatory disease where the gums recede from the teeth and form deep pockets that can become infected, are major reasons for tooth loss. Approximately half of US adults aged 30 and older have gum disease, which in addition to being associated with cognitive decline, has been linked to heart disease, diabetes, and obesity.
“Examining the mouth can be informative about general health,” says Garcia, who is also the research director of the Northeast Center for Research to Evaluate and Eliminate Dental Disparities. “Mouth care is indicative of other self-care behaviors.”
Garcia was a coinvestigator on a study, funded by the National Institutes of Health (NIH), with Professor Elizabeth Krall Kaye, also of the Department of Health Policy & Health Services. They found that for each tooth lost per decade, the risk of doing poorly on cognitive tests increased approximately 8 to 10 percent, and more cavities translated to lower cognition as well. Their findings were published in the Journal of the American Geriatrics Society in 2010.
“The large group of people studied over a period of years allowed us to see the clear chronological relationship in the analyses,” he says. “The cognitive decline came after the dental problems.”
The Veterans Affairs (VA) Normative Aging and Dental Longitudinal Study began in 1960 with men from the Boston metropolitan area who return every three years for medical and dental examinations. Cognition exams were introduced in 1993.
Garcia’s research on obesity and heart disease, funded by the NIH/National Institute of Dental and Craniofacial Research (NIDCR), also used the VA cohort data to “take advantage of the long observation period and the rich data to control or adjust for other variables, such as smoking and alcohol consumption,” he says. In 2012, results published in the Journal of Clinical Periodontology linked obesity to subsequent periodontal disease. A companion paper in the Journal of Dental Research examined changes in overweight men over time as a predictor of gum disease progression. Garcia’s earlier research on heart disease, published in the Annals of Neurology, showed that men younger than 65 with periodontal bone loss from a history of gum disease were at a greater risk for cardiovascular disease.
Garcia is a coinvestigator with Kaye on another NIH/NIDCR-funded project to examine the five risk factors that increase the chance of heart disease, diabetes, and stroke in older men with periodontal disease with data from the VA study. “We are now looking at metabolic syndrome and the risk of oral disease using a similar analytic approach,” says Garcia.
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