Many senior citizens swear by oral supplements and the benefits they bring. However, the scientific evidence is mixed. While animal and observational studies have indicated possible protective effects on the aging brain, controlled trials with humans have not shown such cognitive benefits.

To try to find definitive answers about whether the supplements actually slow cognitive decline, researchers from China used long-term patient data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) and studied highly detailed brain scans.

The study examined cognitive and brain imaging changes over five years in 273 omega-3 users and compared them with a control group of 546 non-users. These were matched for age, sex, genetics, and diagnosis.

The results revealed that participants taking omega-3 supplements showed a more rapid decline across the three primary cognitive assessments (MMSE, ADAS-Cog13, and CDR-SB) each person completed during the study.