DHA Levels in Older Adults May Predict Dementia Risk
Those in highest quartile may have reduced risk of dementia and Alzheimer disease
TUESDAY, Nov. 21 (HealthDay News) -- Older adults with high plasma levels of docosahexaenoic acid, or DHA, may have a significantly lower risk of developing dementia and Alzheimer disease, according to a study in the November issue of the Archives of Neurology.
Ernst J. Schaefer, M.D., of the Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging at Tufts University in Boston, and colleagues studied 899 participants in the Framingham Heart Study with an average age of 76 who were dementia-free at baseline.
After nine years, 99 subjects developed dementia, including 71 with Alzheimer disease. The researchers found that subjects with top-quartile DHA plasma levels had a 47 percent lower risk of developing dementia and a 39 percent lower risk of developing Alzheimer disease than subjects in the lower three quartiles. Top-quartile subjects reported that they consumed an average of three fish servings per week while the other subjects ate significantly less fish.
"There is a strong biological basis for the association of DHA and neuroprotection. Lipids are the primary structural component of the adult brain, making up 50 percent to 60 percent of the brain dry weight," states the author of an accompanying editorial. "The DHA is most concentrated in neurons of the cerebral cortex, synaptosomes, and the mitochondria -- areas of the brain with the highest metabolic activity."