Omega-3 Fatty Acid Slows Alzheimer’s

DHA-Rich Diet May Help Prevent Alzheimer’s Disease

Medically Reviewed by Louise Chang, MD on April 18, 2007
From the WebMD Archives

April 18, 2007 -- Eating a diet rich in a certain type of omega-3 fatty acid may slow or even prevent Alzheimer’s disease, according to a new study in mice.

Researchers found feeding mice bred to develop Alzheimer’s disease a diet rich in docosahexaenoic acid (DHA) slowed the accumulation of two proteins associated with the brain-clogging plaques and tangles implicated in the disease.

Previous studies have suggested that DHA may be useful as a treatment for Alzheimer’s disease, but researchers say this study is among the first to suggest that the omega-3 fatty acid might delay or prevent the development of the disease later in life.

“We are greatly excited by these results, which show us that simple changes in diet can positively alter the way the brain works and lead to protection from Alzheimer’s disease pathology,” says researcher Frank LaFerla, professor of neurobiology and behavior at the University of California, Irvine, in a news release.

DHA is a type of omega-3 fatty acid found in fish, organ meats, eggs, micro-algae, and supplements.

DHA May Stall Alzheimer’s

In the study, researchers examined the effects of DHA in mice bred to develop the plaques and brain tangles associated with Alzheimer’s disease. The results appear in the Journal of Neuroscience.

One group of mice was given food that resembled the typical American diet, with 10 times more omega-6 fatty acids, such as those found in corn, peanut and sunflower oils, than omega-3 fatty acids.

Omega-6 fatty acids are essential fatty acids like omega-3 fatty acids that people obtain from their diet. A high ratio of omega-6 to omega-3 has been linked to increased risk for many diseases.

Three other groups were fed diets with a healthier 1:1 ratio of omega-6 to omega-3 fatty acids: One received supplemental DHA only, and the other two groups received DHA plus additional omega-6 fatty acids. The amounts of carbohydrate, protein, and calories were the same for all the diets.

After three months, all of the mice on the DHA diets had lower levels of beta-amyloid and tau proteins than those in the control group. But at nine months, only those on the DHA-only diet had lower levels of both proteins.

Researchers say those results suggest that DHA works better on its own than with omega-6 fatty acids. They say additional studies on DHA in humans are now needed to assess how well the omega-3 fatty acid might work against Alzheimer’s disease.

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SOURCES: Green, K. Journal of Neuroscience, April 18, 2007; vol 27. News release, University of California, Irvine.

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