Researchers from the University of Southern California, Los Angeles have found a link between gum disease and Alzheimer's disease. A new study of dementia in identical twins suggests that exposure to inflammation early in life quadruples the risk of developing Alzheimer's. Dr Margaret Gatz, lead author and Professor of Psychology in the USC College of Letters, Arts and Sciences, presented her findings at the first Alzheimer's Association International Conference on Prevention of Dementia last month in Washington, DC. If the link is confirmed, it would add inflammatory burden to the short list of preventable risk factors for Alzheimer's.
The study, Potentially Modifiable Risk Factors From Dementia: Evidence From Identical Twins, used information from 20,000 participants in the Swedish Twin Registry where surveys were completed in the 1960s, when the registry was created, and from hospital discharge records. These contained information about participants' education, activities and health history. The researchers found 109 “discordant” pairs of twins, where only one twin had been diagnosed with dementia.
The surveys included questions about loose or missing teeth and the team used the answers to build a crude indicator of periodontal disease. The survey concluded that it is not that good oral health can prevent Alzheimer's, but that an inflammatory burden early in life, as represented by chronic gum disease, may have severe consequences later.
Dr Gatz was inspired to focus on inflammation by the work of USC gerontologists Caleb Finch and Eileen Crimmins, who published a paper in the journal Science linking today's record life spans to lower rates of childhood infectious diseases, such as gum disease, flu, rheumatic fever, tuberculosis and other illnesses. Such diseases are often preventable, raising hope for prevention of Alzheimer's. “If what we're indexing with periodontal disease is some kind of inflammatory burden, then it is probably speaking to general health conditions,” Dr Gatz said. “There was quite a lot of periodontal disease in our twins, and at that time in Sweden there was a lot of poverty.”