Long-term omega-3 supplementation may lead to a 64% reduction in Alzheimer's disease risk, according to observational data from the Alzheimer's Disease Neuroimaging Initiative involving older adults over a 6-year period. Randomized controlled trials, however, have yielded mixed findings. A comprehensive review of 48 studies indicated that increased dietary intake of omega-3s, specifically DHA and EPA, correlates with reduced dementia risk among over 100,000 participants. The evidence suggests stronger benefits for individuals over 73, particularly those with mild cognitive impairment and APOE ε4 carriers, with substantial protective effects noted at higher levels of intake.

Source: The American Journal of Clinical Nutrition