They noted there is emerging evidence that Omega-3 polyunsaturated fatty acids (PUFA) supplements can decrease aggression, but added experimental studies with adults from non-specific populations are scarce.
Writing in the journal Psychiatry, they hypothesized that Omega-3 supplements would decrease self-reported aggression among non-clinical participants.
They conducted a double-blind randomized trial whereby two groups of participants (N = 194) aged 18–45 from the general population followed a sicx-weeks treatment with 638 mg docosahexaenoic acid (DHA) and 772 mg eicosapentaenoic acid (EPA) per day or the equivalent quantity of copra oil (placebo).
Self-reported aggressiveness was measured at baseline and after the 6-week treatment period.
Findings showed that Omega-3 supplements significantly decreased self-reported aggressiveness at the end of the 6-week period (d = 0.31).
The research team added these findings had a number of advantages over existing studies.
“First, most omega-3 fatty acid studies have very small sample sizes, which can produce unreliable results. In a meta-analysis, seven out of eight experiments had fewer than 50 participants,” they wrote.
“Second, most omega-3 fatty acid studies sample participants from vulnerable populations, like children suffering from ADHD and adults suffering from a variety of mental disorders. The present experiment sampled participants from the general population.”
They also pointed out that several earlier experiments combined omega-3 fatty acids with other nutrients known to influence aggression, making it impossible to assess the role played by omega-3 alone, while others used projective tests to measure aggression, “which is an indirect rather than a direct test.”
They added: “In sum, the present experiment tests the effect of omega-3 supplements on self-reported aggression in a relatively large sample of healthy adults, using a reliable measure of aggressiveness.”
The researchers, which were funded by France’s Ministry of Health, concluded that this experiment suggests that omega-3 administration may reduce physical aggression in the general population.
“This is an important positive effect of omega-3 supplements, in addition to their many other positive benefits,” they added.