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Omega-3 supplements may help lower aggression levels in people, a new study suggests. Marc Tran/Stocksy
  • Scientists from the University of Pennsylvania have found that people who take omega-3, which is found in fish, flaxseed, and walnuts, are less likely to have aggressive and violent outbursts.
  • Poor nutrition has been cited as a connection to aggressive and antisocial behavior, and combining cognitive behavioral therapy (CBT) with omega-3 in regular diets could be beneficial.
  • Adding omega-3s to a daily dietary regime is fairly easy given the accessibility of supplements and grocery-store items like edamame, seaweed, flaxseeds, and anchovies.

Omega-3 fatty acids, a beneficial nutrient found in foods like sardines, salmon, walnuts, and chia seeds, can reduce aggressive and violent behavior, according to a new paper published in the journal Aggression and Violent Behavior.

The paper, authored by University of Penn professor Adrian Raine with Lia Brodrick of the Perelman School of Medicine, examined 3,918 participants from multiple studies, samples, and laboratories between 1996 to 2024.

The meta-analysis found that omega-3 could reduce “reactive aggression,” which is manifested by impulsive responses to provocation, and “proactive aggression,” which is predetermined or “predatory,” as the study says.

Dr. Raine, who is also the Richard Perry University Professor of Criminology, Psychiatry, and Psychology, has for years studied neurocriminology, aggressive behavior in adults and children, and antisocial behavior. This paper used 35 independent samples included in 29 studies from 19 independent laboratories. The results applied broadly across multiple populations, ages, and genders.

“Results of this study show that omega-3 supplementation significantly reduces aggressive behavior in the short-term, albeit at a modest level,” the paper says. “Given the enormous economic and psychological cost of aggression and violence in society, even small effects sizes need to be taken seriously.”

“Omega-3 supplementation has been argued to benefit a number of psychopathologies, including depression and anxiety, and more debatably schizophrenia-spectrum disorders. It certainly influences the serotonin system in a beneficial manner, but this is not unique as it influences other neurotransmitters too,” Dr. Raine told Medical News Today.

“The challenge we have is understanding exactly how omega-3 influences neurophysiology in a specific way to benefit mental health,” he said.

Omega-3s are generally known to have a number of physical health benefits. They help maintain cell structures, can prevent obesity and heart disease, and can reduce inflammation in the body. However, the body is not able to produce them itself, so external supplements or sources of nutrition are necessary to get them.

There are three types of omega-3 fatty acid:

  • alpha-linolenic acid (ALA), present in flaxseeds, chia seeds, and walnuts.
  • eicosapentaenoic acid (EPA)
  • docosahexaenoic acid (DHA)

DHA and EPA are mostly present in cold-water fatty fish, such as mackerel, salmon, herring, and sardines.

Melanie Murphy Richter, a registered dietitian nutritionist and the director of communications for the nutrition company Prolon, who was not involved in the research, told Medical News Today that in addition to their physical benefits, omega-3s can interact with the brain in multiple ways.

“The presence of omega-3s, most especially DHA, can make these vesicular membranes more receptive to the signals that prompt the release of serotonin. By improving this process, more serotonin is available to transmit between neurons in the brain and other parts of the central nervous system (CNS). Additionally, Omega-3s can impact the expression of certain genes by increasing the functionality of certain enzymes that create serotonin’s precursor, 5-HTP. This can also enhance serotonin production,” Richter said.

“Omega-3s can make a wonderful complement to the antidepressant effects of SSRIs by increasing the availability of serotonin within the membranes of the brain. Due to their anti-inflammatory capabilities, omega-3s can also reduce inflammation in the brain, which can help enhance SSRI function.”
— Melanie Murphy Richter, RDN

Raine’s paper points out that “poor nutritional status is a risk factor for externalizing behavior problems,” which has prompted greater interest in looking at how nutritional supplements can reduce such behavior across a society.

It cites several studies in explaining that omega-3 could be a bridge between nutritional deficiency and violent or aggressive behavior, stating that “correlational research has also shown that fish consumption is negatively associated with cross-country homicide rates.”

Richter said that omega-3s can regulate serotonin and mood, which when coupled with other treatment avenues, can make a difference in antisocial or aggressive behavior.

If, for instance, a person’s dysregulated moods and emotions are related to chronic inflammation as a result of poor diet or other toxic environmental factors, Omega-3 supplementation can have a decently big impact on helping to regulate emotional outbursts like road rage. In fact, one study showed that a higher level of Omega-3 status was linked to lower aggressive behavior in adult prisoners. Because of the effects on inflammation, Omega-3 can play a big role in the reduction of irritability and anxiety. The presence of Omega-3 can increase the availability of serotonin release from membranes in the brain, helping to improve overall mood and relaxation,” Richter said.

Omega-3s and CBT

“Omega-3s can make a wonderful adjunct therapy to cognitive behavioral therapy (CBT). Many people have not learned how to acknowledge and work through certain emotions like anger or rage. CBT can teach practical tips on how to relax, problem-solve, and detach from certain external circumstances.”
— Melanie Murphy Richter, RDN

Raine echoed this sentiment, saying that the combination of therapy and nutritional supplementation is extremely promising.

“We have done some studies comparing omega-3 with CBT and social skills training to reduce aggression, and in some cases, we find omega-3 performs better,” Raine said. “But we have also found that the combination of omega-3 with CBT can be especially beneficial in reducing aggression. So, an approach in which omega-3 supplements other psychological interventions could be particularly promising.”

Fatty fish like salmon, sardines, mackerel, and anchovies are an easy way to add omega-3s to your diet. Richter noted that chia seeds, flaxseeds, walnuts, hemp seeds, seaweed, and edamame also are good sources of alpha-linolenic acid.

There are also supplements that can be found in stores or online. Richter recommended vetted brands such as Nordic Naturals.

“This brand is one of the premier by way of potency, purity, freshness, and clean ingredients. I also love that they have COA certifications and have been specializing in Omega-3s for many years,” she said.