Omega-3 polyunsaturated fatty acid supplementation and cognition: A systematic review and meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 26040902 · doi:10.1177/0269881115587958
What was done
A systematic review and meta-analysis of randomized controlled trials evaluated the effect of omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation on cognitive performance. Searches included trials in adults and school-aged children who were either healthy and typically developing or diagnosed with attention deficit hyperactivity disorder and related neurodevelopmental disorders.
What was found
Across 24 included studies, n-3 PUFA supplementation did not improve any cognitive performance measures in the whole sample, the typically developing subgroup, or the ADHD and related disorders subgroup. Supplementation improved short-term memory only in participants with low baseline n-3 PUFA status. The abstract reports no numerical effect sizes, test statistics, or confidence intervals.
Why it matters
These findings challenge widespread claims promoting omega-3 supplements as general cognitive enhancers or treatments for ADHD. Evidence of benefit is marginal and restricted to individuals with baseline deficiency.
Limits
The abstract provides no participant counts, effect sizes, variance measures, or p-values. Supplement dosages, treatment durations, and specific cognitive testing instruments are not detailed.
Cited by
- contradicts Studies show that 1 gram per day of omega-3 is safe in children, lowers ADHD symptoms, and improves cognition.