title: Omega-3 polyunsaturated fatty acid supplementation and cognition: A systematic review and meta-analysis.
abstract: 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.
  
  
  OBJECTIVE
  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.
authors.affiliation: King's College London, MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, London London, UK ruth.cooper@kcl.ac.uk.
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Cooper
authors.affiliation: King's College London, MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, London London, UK.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Tye
authors.affiliation: King's College London, MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, London London, UK.
authors.forename: Jonna
authors.initials: J
authors.lastname: Kuntsi
authors.affiliation: King's College London, MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, London London, UK.
authors.forename: Evangelos
authors.initials: E
authors.lastname: Vassos
authors.affiliation: King's College London, MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, London London, UK.
authors.forename: Philip
authors.initials: P
authors.lastname: Asherson
mesh_terms: D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy; D002648:Child; D003071:Cognition / Q000187:drug effects*; D019587:Dietary Supplements; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D008570:Memory, Short-Term / Q000187:drug effects; D016032:Randomized Controlled Trials as Topic
chemical_list: D015525:Fatty Acids, Omega-3
keywords: Attention deficit hyperactivity disorder; cognition; meta-analysis; omega-3; randomised controlled trial