Omega-3 Supplements Linked to Cognitive Decline in Surprising New Study

An observational ADNI study found older adults taking omega-3 supplements had faster cognitive decline over about five years than nonusers.

Brain imaging linked supplement use to lower glucose metabolism, while amyloid, tau, and gray matter measures did not differ.

The results were seen with fish oil, krill oil, and flaxseed oil, and were adjusted using matched groups including APOE ε4 status.

Because the study was observational, it cannot prove omega-3 supplements cause the decline, but it raises questions about their brain-protection benefits.