Omega-3 supplementation reduces aggressive behavior: A meta-analytic review of randomized controlled trials

There is increasing interest in the use of omega-3 supplements to reduce aggressive behavior. This meta-analysis summarizes findings from 29 RCTs (randomized controlled trials) on omega-3 supplementation to reduce aggression, yielding 35 independent samples with a total of 3918 participants. Three analyses were conducted where the unit of analysis was independent samples, independent studies, and independent laboratories. Significant effect sizes were observed for all three analyses (g = 0.16, 0.20, 0.28 respectively), averaging 0.22, in the direction of omega-3 supplementation reducing aggression. There was no evidence of publication bias, and sensitivity analyses confirmed findings. Moderator analyses were largely non-significant, indicating that beneficial effects are obtained across age, gender, recruitment sample, diagnoses, treatment duration, and dosage. Omega-3 also reduced both reactive and proactive forms of aggression, particularly with respect to self-reports (g = 0.27 and 0.20 respectively). It is concluded that there is now sufficient evidence to begin to implement omega-3 supplementation to reduce aggression in children and adults - irrespective of whether the setting is the community, the clinic, or the criminal justice system.