Fish Oil Helps Protect The Brain From Alzheimer's Disease

The December 26, 2007 issue of The Journal of Neuroscience reported the finding of Greg Cole and colleagues at the University of California, Los Angeles of a mechanism by which the omega-3 fatty acid docosahexaenoic acid (DHA), found in fish oil, helps prevent Alzheimer's disease. Research has suggested a protective effect for fish oil against Alzheimer's disease and dementia, but the mechanisms responsible for this benefit had not been determined.

Dr Cole, who is a professor of medicine and neurology at UCLA's David Geffen School of Medicine, and his colleagues found that DHA increases the production of a protein known as LR11, which is reduced in Alzheimer's disease patients. LR11 decreases the formation of beta amyloid, a protein that forms brain plaques which characterize the disease.

Dr Cole's team was able to confirm DHA's effect by adding fish oil or DHA to the diet of rodents, or applying it to rat neurons. "We found that even low doses of DHA increased the levels of LR11 in rat neurons, while dietary DHA increased LR11 in brains of rats or older mice that had been genetically altered to develop Alzheimer's disease," Dr Cole stated. DHA was also shown to increase LR11 when administered to cultured human neurons.

What the research team has yet to determine "is what the optimal dose should be," Dr Cole noted. "It could be that a smaller amount might be helpful, especially in a place like the south of France, where people are already on a Mediterranean diet."

However, in the United States, where fish consumption is low, a greater dose may be needed. "There's a deficiency of DHA to begin with," Dr Cole stated, "and this may contribute to the low LR11 seen in many Alzheimer's patients."