Arguments in favor of taking omega-3's 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 behavioral problems.

For years, University of Pennsylvania neurocriminologist Adrian Raine has been studying whether omega-3 supplements can reduce aggressive behavior, publishing five randomized controlled trials from around the world. He found significant effects, but wanted to know whether those results extended beyond his lab.

Now Raine has found further evidence for the effectiveness of omega-3 supplements in a meta-analysis of 29 randomized controlled trials. The analysis shows modest short-term effects—he estimates that the intervention reduces aggression by 30%—across age, gender, diagnostic groups, and treatment duration and dosage.

Raine is the lead author of a new paper published in the journal 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 justice system," Raine says. "Omega-3 is not a magic bullet that will completely solve the problem of violence in society. But can it help? Based on this data, we strongly believe it can, and we need to act on this new knowledge."

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

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 studies, independent samples, or laboratories.

Only one of the 19 labs followed up with participants after they stopped taking the supplements, so the analysis focused on changes in aggression from the start 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 paper says, "the next step will be to assess 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 supplements improve prefrontal cortex function, whether genetic variation influences omega-3 treatment outcomes, and whether self-reports of aggression provide stronger evidence of effectiveness than 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 should be educated about the potential benefits of omega-3 supplements," the authors write.

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