Research Review: Omega-3 supplementation to reduce antisocial behavior - a systematic review and meta-analysis of randomized controlled trials.

In 30 seconds

This systematic review and meta-analysis assessed whether omega-3 supplementation reduces antisocial behavior. It included 25 randomized controlled trials involving 2,889 participants and analysed effects using independent studies and independent laboratories as units. Both analyses found small effects favouring supplementation: g = .13 and g = .14, respectively (p < .001). Evidence of publication bias was equivocal. Analyses by age, gender, dose, sample size, and study quality did not identify significant differences, although effects were larger among unmedicated participants. Combining these results with a separate meta-analysis yielded an effect size of g = .22 for externalizing behavior across 36 nonoverlapping trials.

Key findings

• Across 25 RCTs and 2,889 participants, effects favoured omega-3 supplementation (g = .13 and .14; p < .001).
• Stratified analyses by age, gender, dose, sample size, and study quality were nonsignificant; effects were larger in unmedicated participants.
• Combined with a recent aggression meta-analysis, 36 nonoverlapping RCTs showed an overall externalizing-behavior effect size of g = .22.
• Evidence of publication bias was equivocal, and the review rated study quality as good.

Why it matters

The pooled randomized-trial evidence suggests a statistically significant but small reduction in antisocial behavior with omega-3 supplementation. This provides a quantitative basis for considering omega-3 as a possible adjunct, while the modest effect and equivocal publication-bias evidence warrant measured interpretation. The findings do not establish which participant groups are most likely to benefit.

What to keep in mind

Evidence of publication bias was equivocal. Stratified analyses did not identify significant differences across the examined participant and study characteristics.