USA Weekend Eat Smart Archive

February 18, 2007

A groundbreaking study at Tufts University has identified the major fatty acid in fish oil that appears to protect brains against dementia and Alzheimer's disease. It's DHA, or docosahexaenoic acid.

Among a big group of elderly Americans, those with the highest blood levels of DHA were about half as apt to develop dementia and 39% as apt to develop Alzheimer's as those with lower blood levels of DHA over a nine-year period. The top 25% of those with the highest blood DHA got about 180 mg DHA a day, or three servings of fish a week, researchers said. In this study, the other major fatty acid in fish oil, EPA (eicosapentaenoic acid), had no effect.