Omega-3 polyunsaturated fatty acid supplementation and cognition: A systematic review and meta-analysis

J Psychopharmacol. 2015 Jul;29(7):753-63. doi: 10.1177/0269881115587958. Epub 2015 Jun 3.


Background: Omega-3 polyunsaturated fatty acids (n-3 PUFAs) are promoted as cognitive enhancers with consumption recommended in the general population and those with neurocognitive deficits such as attention deficit hyperactivity disorder (ADHD). However, evidence from randomised placebo-controlled trials is inconclusive.

Aims: This study aimed to conduct a systematic review and meta-analysis examining the effect of n-3 PUFA supplementation on cognition in healthy populations and those with ADHD and related disorders (RDs).

Methods: Databases were searched for randomised controlled trials (RCTs) in adults and school-aged children (who were healthy and typically developing (TD) or had ADHD or a related-neurodevelopmental disorder (ADHD+RD) which assessed the effects of n-3 PUFA on cognition.

Results: In the 24 included studies n-3 PUFA supplementation, in the whole sample and the TD and ADHD+RD subgroup, did not show improvements in any of the cognitive performance measures. In those with low n-3 PUFA status, supplementation improved short-term memory.

Conclusions: There is marginal evidence that n-3 PUFA supplementation effects cognition in those who are n-3 PUFA deficient. However, there is no evidence of an effect in the general population or those with neurodevelopmental disorders. This has important implications given the widespread advertisement and consumption of n-3 PUFA; claims of cognitive benefit should be narrowed.

Keywords: Attention deficit hyperactivity disorder; cognition; meta-analysis; omega-3; randomised controlled trial.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Review
  • Systematic Review

MeSH terms

  • Adult
  • Attention Deficit Disorder with Hyperactivity / drug therapy
  • Child
  • Cognition / drug effects*
  • Dietary Supplements*
  • Fatty Acids, Omega-3 / administration & dosage
  • Fatty Acids, Omega-3 / pharmacology*
  • Humans
  • Memory, Short-Term / drug effects
  • Randomized Controlled Trials as Topic


  • Fatty Acids, Omega-3