Fish fanatics, rejoice: There’s even more evidence to support DHA’s role in Alzheimer’s disease prevention. A recent study published in The Journal of Neuroscience shows that eating a diet rich in DHA, or docosahexaenoic acid, can limit the buildup of beta-amyloid on the brain, a condition commonly seen in Alzheimer’s patients (2005, vol. 25, no. 12). Scientists fed mice different diets of omega-3 fatty acids to determine that a high DHA intake can reduce brain plaque levels by about 40 percent. DHA is found naturally in fatty fish and organ meats and is sold in supplemental form at many natural products stores.