USC study finds fish oil supplements do not improve memory

A two-year clinical trial conducted by researchers at the Keck School of Medicine at the University of Southern California has found that high doses of omega-3 fatty acid supplements do not lead to measurable improvements in memory or cognitive function, nor do they protect against brain shrinkage.

The study, published in eBioMedicine, followed 365 participants aged 55 to 80 who were at increased risk for Alzheimer's disease. Nearly half of the participants were carriers of the APOE4 genetic variant. Participants were divided into two groups: one receiving a daily fish oil supplement containing 2000 mg of docosahexaenoic acid (DHA), and another receiving a placebo.

While researchers confirmed that the supplements successfully increased DHA concentrations in the cerebrospinal fluid by approximately 17 percent after six months, this biological increase did not translate into clinical benefits. The study suggests that while omega-3 molecules can reach the brain, oral supplementation does not guarantee protection against cognitive decline or the structural changes associated with Alzheimer's disease.