Arguments for Omega-3 Supplementation to Reduce Aggression

People who regularly eat fish or take fish oil supplements get omega-3 fatty acids, which play an important role in brain function. It has long been established that aggressive and violent behavior is associated with processes in the brain, and poor nutrition is a risk factor for behavior problems.

For many years, University of Pennsylvania neurocriminologist Adrian Raine has been studying the possibility of reducing aggressive behavior with omega-3 supplements, publishing five randomized controlled trials from different countries. He found significant effects, but wanted to know whether the results generalized beyond his laboratory.

Rain has now found further evidence of the effectiveness of omega-3 supplements by conducting a meta-analysis of 29 randomized controlled trials. This analysis shows modest short-term effects—it estimates that the intervention reduces aggression by 30%—across different age, gender, diagnostic groups, and treatment duration and dosage.

Rane is the lead author of a new paper published in the journal of Aggressive and Violent Behavior, co-authored with Leah Brodrick of the Perelman School of Medicine.

"I think it's time to introduce omega-3 supplements to reduce aggression, whether it's in the community, the clinic or the criminal system," says Raine. "Omega-3 is not a magic wand that will completely solve the problem of violence in society. But can it help? Based on this data, we firmly believe that it can, and we must begin to act on this new knowledge."

He notes that omega-3 is also beneficial for treating heart disease and hypertension, and it is inexpensive and safe to use. "At the very least, parents seeking treatment for an aggressive child should know that in addition to any other treatment their child is receiving, an extra serving or two of fish per week may also help," says Raine.

This meta-analysis shows that omega-3 reduces both reactive aggression, which is a response to provocation, and proactive aggression, which is a planned action.

The study included 35 independent samples from 29 studies conducted in 19 independent laboratories from 1996 to 2024, with a total of 3,918 participants. It found statistically significant effects regardless of whether effect sizes were averaged across a study, an independent sample, or a laboratory.

Only one of the 19 laboratories followed up participants after supplementation ended, so the analysis focused on changes in aggression from the beginning to the end of treatment for the experimental and control groups, which averaged 16 weeks. "While it is important to know whether omega-3 reduces aggression in the short term," the article states, "the next step is to evaluate whether omega-3 can reduce aggression in the long term."

The article notes several other possible avenues for future research, such as determining whether brain imaging shows that omega-3 supplementation improves prefrontal cortex function, whether genetic variation influences the outcome of omega-3 treatment, and whether self-reports of aggression provide more strong evidence of effectiveness compared with observer reports.

"At the very least, we argue that omega-3 supplements should be considered as an adjunct to other interventions, whether psychological (eg, cognitive behavioral therapy) or pharmacological (eg, risperidone), and that caregivers, the potential benefits of omega-3 supplements should be communicated," the authors write.

They conclude: “We believe the time has come to both introduce omega-3 supplements into practice and continue scientific research into their long-term effectiveness.”