Consuming a diet rich in the omega-3 fatty acid docosahexanoic acid (DHA) may help prevent or treat Alzheimer's disease, findings from an animal study suggest.
In the study, which is reported in The Journal of Neuroscience, mice that ate DHA-enriched chow showed less beta-amyloid build-up in the brain than mice fed regular chow. Beta-amyloid is a protein that forms the characteristic brain plaques seen in patients with Alzheimer's disease.
"These results suggest that dietary DHA could be protective against beta-amyloid production, accumulation, and potential downstream toxicity," wrote senior author Dr. Greg M. Cole, Professor of Medicine and Neurology at University of California at Los Angeles.
"While there are powerful new experimental drugs that may also work, we were doubly excited to get this result with a treatment that has already been proven so safe in humans that it is added to infant formula. Because of this proven safety and epidemiological evidence associating low DHA intake with increased risk of Alzheimer's disease, we are now hopeful that clinical trials will show that DHA can prevent or help treat this terrible disease," Dr. Cole continued.
The findings in these mouse models are consistent with a recent report by the Agency for Healthcare Research and Quality (AHRQ), an agency in the Department of Health and Human Services (HHS). AHRQ evaluated the data between omega-3 fatty acid consumption and Alzheimer's and found that, "Total omega-3 fatty acid consumption and consumption of DHA (but not ALA or EPA) were associated with a significant reduction in the incidence of Alzheimer's."
Cole's team used a mouse model of Alzheimer's disease and fed the animals low- or high-DHA chow or regular chow. The animals were fed the assigned diet until 22.5 months of age, at which point brain tissue was obtained and tested for amyloid build-up.
DHA is an omega-3 fatty acid found throughout the body. It is a major structural fatty acid in the gray matter of the brain and a key component of the heart. Natural food sources of DHA are limited primarily to fatty fish and organ meat causing Americans to have among the lowest dietary intake of DHA in the world.
The high-DHA diet reduced total amyloid level by 70 percent compared with the other diets, the investigators report. Moreover, brain plaques were reduced by 40.3 percent.
Several studies are currently underway to determine if fatty acids like DHA offer any benefits for patients with mild-to-moderate Alzheimer's disease, the authors add.
The Journal of Neuroscience, March 30, 2005.