• 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.

Do omega-3s affect mental health?

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

How do omega-3s regulate aggression?

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 studyTrusted Source 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.”

Best sources of omega-3s

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.

What are the benefits of omega-3?

Omega-3 fatty acids are part of a group of polyunsaturated fatty acids that support several functions in the body. 

According to the National Center for Complementary and Integrative Health (NCCIH)Trusted Source,  the three main types of omega-3 fatty acids are docosahexaenoic acid  (DHA), eicosapentaenoic acid (EPA), and alpha-linolenic acid.

The NCCIHTrusted Source lists some of their possible benefits, stating that:

  • High doses of omega-3 can help reduce triglyceride levels in the blood.
  • These fats may help alleviate symptoms of rheumatoid arthritis.
  • Dietary omega-3 may help prevent heart disease, but supplements may not.

The  NCCIH also notes that other claims about fatty acids, whether from a  person’s diet or supplements, are either inconclusive or remain  unsupported by the findings of studies.

A 2019 study found that omega-3 supplements did not lower incidences of  cardiovascular disease events. However, a 2020 article published on the  same group after further analyses found that in people who ate less than  1.5 servingsTrusted Source of fish per week, taking supplements led to a decrease in their risk of developing heart disease. 

Another trial, known as REDUCE-IT,  had similar results relating to cardiovascular events and death. The  researchers found that in comparison with a placebo, omega-3 supplements  reduced high blood triglyceride levels and the risk of cardiac-related  events or death.

However, participants all had high triglyceride levels at baseline and were on statin therapy. This could mean that the results apply only to specific groups of people and not the general population. 

It is also important to note that the researchers used icosapent ethyl (Vascepa), which is a prescription omega-3 fatty acid. The Food and Drug Administration (FDA) has approvedTrusted Source Vascepa, and a similar medication called Lovanza. This is unlike other  omega-3 supplements, which the FDA does not directly regulate. Doctors  can use these prescription drugs to lower triglyceride levels in people  living with hypertriglyceridemia. 

According to a 2019 journal article,  the REDUCE-IT study is an anomaly among other studies that generally  show limited evidence of omega-3 reducing the risk of cardiovascular  events. Though the author urges further research, they also acknowledge  that taking an omega-3 supplement is likely not a bad idea.

In 2019, the FDATrusted Source announced it would not object to certain health claims about omega-3 supplements reducing the risk of hypertension and coronary heart disease. In other words, as long as manufacturers follow the FDA’s guidelines, they can claim their products may reduce these risks.

What to look for in omega-3 supplements

The authors of a 2016 studyTrusted Source state there are major differences between prescription omega-3s such as  Lovaza and dietary supplements. The study outlines that prescription  omega-3 supplements are superior due to:

  • rigorous regulatory standards
  • the consistency of effectiveness 
  • the consistency of safety

People interested in taking omega-3 supplements should talk with a doctor first. This is particularly true for pregnant or nursing people and those taking prescribed medications or other supplements.


When selecting an omega-3 supplement, a person should consider the following:

  • how much the supplement will likely cost
  • certifications from third-party reviewers for safety and purity standards
  • the product’s dosage 
  • supplement type, such as gummy or capsule

Also, according to the NCCIHTrusted Source, there are no finalized studies that indicate whether omega-3 fish oil supplements are safe for people who have seafood allergies.

The Association of UK Dietitians recommends that people check the vitamin A content of omega-3 supplements, as daily vitamin A intake from food and supplements combined should not exceed 1.5 milligrams (mg).

In addition, individuals should choose products that have the least amount of heavy metals or fillers. 

There are also supplements suitable for those following a vegan or gluten-free diet. 

How we chose the best omega-3 supplements

Medical News Today selects omega-3 supplements that meet the following criteria:

  • Ingredients: MNT chooses products that contain high quality ingredients and are free of fillers, artificial flavors, and preservatives.
  • Dosage: MNT selects products that contain safe doses of omega-3 fatty acids.
  • Quality: MNT chooses  products that are third-party certified or have undergone testing by an  independent lab for safety and quality whenever possible.
  • Vetting: MNT selects supplements that its team of medical experts has vetted and approved.