Data from almost 4,000 participants collected over 28 years indicated that omega-3 supplementation may reduce both reactive and proactive forms of aggression in the short-term, albeit modestly, according to the meta-analysis published in Aggression and Violent Behavior.
“Regarding clinical implications, based on these findings, our considered opinion is that there is now sufficient evidence to begin to implement omega-3 supplementation to reduce aggression in children and adults at a modest level—irrespective of whether the setting is the community, the clinic or the criminal justice system,” wrote Adrian Raine and Lia Brodrick from the University of Pennsylvania.
“At the very least, we would argue that omega-3 supplementation should be considered as an adjunct to other interventions, whether they be psychological (e.g. CBT [cognitive behavioral therapy]) or pharmacological (e.g. risperidone) in nature, and that caregivers are informed of the potential benefit of omega-3 supplementation.”
Suitable settings
Commenting independently on the study's findings, Dr Kaitlin Roke, Director of Scientific Communication and Outreach for the Global Organization for EPA & DHA Omega-3s (GOED), told us: "The authors concluded that increased intake of EPA+DHA omega-3s resulted in a “modest and short-term reduction in aggression” and stated that “we believe the time has come both to execute omega-3 supplementation in practice and also to continue to scientifically investigate its longer-term efficacy.” This point is important, as many areas within omega-3 research continue to develop without a thoughtful pause and evaluation of the existing literature.
"Based on the evidence in this publication, it would be interesting to learn which setting (classroom, workplace, prison, etc.) would be the most suitable to implement the findings - where increased EPA+DHA intake may reduce aggressive behavior."
Study details
Raine and Brodrick pooled data from 29 RCTs with a total of 3,918 participants, with a mean omega-3 dose of 1.18 grams and a mean duration of 16.4 weeks. The data indicated that omega-3 supplementation had a significant effect size of 0.22 in the direction of omega-3 supplementation reducing aggression.
While this effect size was considered “modest”, the researchers noted that the effect applies “broadly across a variety of different populations and cuts across age and gender.
“Given the enormous economic and psychological cost of aggression and violence in society, even small effects sizes need to be taken seriously,” they wrote.
Commenting on the potential mechanism(s) of action, Raine and Brodrick noted that omega-3s constitute about 35% of the cell membrane and have been implicated in neurogenesis and nerve cell signaling. The anti-inflammatory activity of omega-3s may also be important from the perspective of the brain, as well as the effects on cerebral blood flow.
“As such, given the undeniable fact that omega-3 is pervasively involved in multiple facets of neuronal biology, it is reasonable to believe that omega-3 supplementation could play a causal role in reducing aggression by upregulating brain mechanisms that may be dysfunctional in such individuals, given the assumption that there is, in part, a neurobiological basis to aggression,” they wrote.
To the naysayers…
The researchers concluded by stating that some people may disagree with their conclusion that omega-3 supplements should be considered as an adjunct to other interventions and that caregivers are informed of the potential benefits of the fatty acids.
“Such objections however bear the heavy burden of specifying how many more RCTs, over how many more decades, showing what specific effect size, at what level of safety, will it take for any intervention to begin to be deemed suitable for implementation to reduce aggression,” they stated in response to such disagreement.
“Given the additional psychological and physical benefits of omega-3 supplementation and ease of implementation, we believe the time has come both to execute omega-3 supplementation in practice and also to continue to scientifically investigating its longer-term efficacy.”
Source: Aggression and Violent Behavior
Volume 78, 101956, doi: 10.1016/j.avb.2024.101956
“Omega-3 supplementation reduces aggressive behavior: A meta-analytic review of randomized controlled trials”
Authors: A. Raine, L. Brodrick