Omega-3 and aggression: what do 28 trials show?

Reactive or proactive aggression: what are we talking about?

In a recent meta-analysis (1), scientists investigated a possible link between omega-3 and aggressive behaviour, distinguishing between two forms of aggression:

• reactive aggression, which is an impulsive response to provocation or frustration;
• proactive aggression, which refers to a more planned behaviour, adopted with the aim of achieving a goal.

This distinction enabled them to examine the effects of omega-3 supplementation on these two types of behaviour separately.

What is the potential link between omega-3 and brain function?

EPA and DHA are long-chain omega-3 fatty acids found particularly in oily fish.

They form part of cell membranes, with DHA being particularly abundant in those of the brain.

Several mechanisms are being investigated to explain how these fatty acids might affect brain function:

• maintaining membrane fluidity and communication between nerve cells;
• modulating certain neurotransmitter systems involved in impulsivity and emotional regulation;
• the production of lipid mediators involved in regulating inflammatory processes (2);
• a possible influence on brain regions involved in attention and cognitive control (3).

The meta-analysis did not directly investigate these brain mechanisms. They therefore represent possible explanations, rather than proof of the cause of the observed results.

EPA and DHA are also available as dietary supplements, particularly in the form of fish oil.

Discover Super Omega 3, an omega-3 dietary supplement (EPA and DHA).

Omega-3 and aggression: a modest short-term effect

The meta-analysis brought together randomised trials comparing omega-3 supplementation with a control intervention and explicitly measuring aggressive behaviour.

In total, it included 28 trials, 35 independent samples and 3,918 children and adults; supplementation lasted an average of 16 weeks and provided an average of 1.18g of omega-3 per day.

However, the protocols varied considerably:

• The doses, the ratios of EPA to DHA, the formulations and the assessment methods varied between trials;
• some supplements also combined omega-3s with vitamins or minerals.

The amount of 1.18g per day therefore corresponds to an average of the doses studied, and not to a recommendation.

Whether the data were grouped by sample, by study or by laboratory, the researchers observed a statistically significant reduction in aggressive behaviour.

However, the average effect size was only g = 0.22, which corresponds to a small effect.

Further analyses also revealed a small statistical effect on reactive aggression and proactive aggression. These results remain preliminary, however, as they were derived from work carried out by a single laboratory.

When the researchers distinguished between the sources of assessment, the effect was evident in the self-report questionnaires completed by the participants, but not in the assessments carried out by those around them.

Furthermore, this comparison was based on a single questionnaire. No clear variations were observed according to age, gender, dose or duration of supplementation, although this does not necessarily demonstrate an identical effect in all individuals.

The study is based solely on randomised trials, and several statistical analyses yielded similar results. However, the protocols and results varied considerably from one trial to another.

The meta-analysis highlights a modest, short-term reduction in aggressive behaviour, which will need to be confirmed over longer periods.

It therefore does not provide sufficient evidence to recommend omega-3s as a treatment for aggression.

Beyond omega-3s: what other approaches are there for emotional balance?

To supplement your omega-3 intake, you could opt for a formula combining EPA and DHA. However, the available research does not allow us to determine whether one of these two fatty acids would be more effective than the other in this context.

Discover the Super Omega 3 dietary supplement, a fish oil-based formula providing EPA and DHA.

Other nutrients and plants are being studied in broader areas such as stress, nervousness and emotional balance, although no effect on aggression can be attributed to them.

For example, magnesium contributes to the normal functioning of the nervous system and to normal psychological functions.

Discover OptiMag, a dietary supplement combining eight forms of magnesium.

Ashwagandha, commonly described as an adaptogenic herb, has been studied in particular for its potential effects on perceived stress and anxiety (4).

Discover Super Ashwagandha, a formula based on ashwagandha root extract.

In more comprehensive formulations, passionflower and schisandra may be combined with other plant extracts and micronutrients.

Discover Stress Relief Formula, which combines passionflower, schisandra, magnesium and B vitamins, amongst other ingredients.

Saffron is also the subject of research into stress and mood. A placebo-controlled trial produced encouraging results in adults experiencing low mood, but these findings still need to be further substantiated (5).

Discover SaffronMag Relax Complex, which combines affron® saffron extract, magnesium bisglycinate, L-theanine and vitamin B6.

These supplements are based on different approaches and have not been directly evaluated in the meta-analysis presented.

Dietary supplements are no substitute for psychological support or medical care.

Although some trials have included children, the products mentioned are intended for adults. In children, during pregnancy or whilst breastfeeding, or whilst on medication, you should always seek advice from a healthcare professional.