Early exposure to inflammatory disease multiplies Alzheimer’s risk, according to researchers at the University of Southern California. A new study of dementia in identical twins suggests that exposure to inflammation early in life quadruples one’s risk of developing Alzheimer’s disease. If confirmed, the link would add inflammatory burden to the short list of preventable risk factors for Alzheimer’s.
Previous studies by USC’s Gatz and others have shown that Alzheimer’s is strongly genetic; if a twin has the disease, his or her identical twin has a 60% chance of developing it. The USC team, which included researchers from the Karolinska Institute in Stockholm, Sweden, assessed 20,000 participants in the Swedish Twin Registry for the 109 “discordant” pairs where only 1 twin had been diagnosed with dementia. Information about participants’ education, activities, and health history came from hospital discharge records as well as surveys they completed in the 1960s when the registry was created. The surveys included questions about loose or missing teeth. Gatz and colleagues used the answers to build a crude indicator of periodontal disease.
“We’re talking about gum disease, but it was measured by teeth lost or loose,” Gatz said. “It’s not perfect. Given it’s not perfect, it’s even more striking that it’s such a solid risk factor…If what we’re indexing with periodontal disease is some kind of inflammatory burden, then it is probably speaking to general health conditions,” Gatz said. “There was in our twins quite a lot of periodontal disease, and at that time in Sweden there was a lot of poverty.”
The conclusion 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. The research for this study was supported by grants from the Alzheimer’s Association and the National Institute on Aging.
(Source: University of Southern California News Service, June 19, 2005)
