More fish = Less aggression.

We've all heard that we should eat more fish. It's chock full of good fats, prevents heart disease, helps with weight loss, and is pretty much as close to a perfect food as you can get. One of the reasons fish is so wonderful is that it's chock full of omega-3 fatty acids. Omega-3 fatty acids help your body regulate inflammation, which means less heart disease, cancer, and memory problems with age. Wikipedia is a good starting point for learning more about this (click here). Less well-known are the effects omega-3s have on behavior. Did you know that countries that consume more fish have significantly lower homicide rates? Also, omega-3 supplements seem to reduce aggression in prisons. These are findings from just a few of the many studies looking at whether omega-3s have profound effects on behavior. Most recently, researchers have begun to wonder whether omega-3s can improve behavior problems in children.

In particular, Dr. Adrian Raine, University of Pennsylvania, and his colleagues conducted a study asking whether omega-3 supplementation causes improvements in behavior problems in children.

To do this, they recruited a sample of 200 children (ages 8-16) and their parents. Parents and their children completed several questionnaires. Parents reported how often their child engages in anxious, depressed, aggressive, inattentive, hyperactive, and antisocial behaviors. Parents also reported how often they engage in antisocial and aggressive behavior. Then children reported their own perceptions of their anxious, depressed, aggressive, inattentive, hyperactive, and antisocial behaviors. The children also provided a small blood sample so the research team could measure their baseline omega-3 fatty acids.

Once they had 200 participating children, the sample was randomized into one of 2 groups: omega-3 or placebo. The two groups had the same amount of omega-3s and behavior problems at the beginning of the study. Children in the placebo group were provided with a 200ml fruit juice drink made of apple, pear, pomegranate, aronia, passion fruit, antioxidants, and vitamin D. The omega-3 group were provided with the same 200ml fruit juice drink with 1000mg of omega-3 added. The omega-3 included 300mg of DHA, 200mg of EPA, 400mg of alpha-linolenic acid, and 100mg of DPA). All participants were instructed to drink this drink every day for 6 months. and record whether they drank it each day.

At the end of 6 months, parents and children completed the same behavioral questionnaires from the beginning of the study, and children provided another blood sample for measurement of omega-3s. Both groups reported that they consumed the fruit juice drink about 6 times per week and indeed, the omega-3 group had greater omega-3s in their blood than the placebo group after 6 months of taking the drink regularly.

Both groups demonstrated equal declines in child behavior problems at the end of the treatment, while parents whose children were in the omega-3 group reported fewer antisocial behaviors. This might suggest what we call a "placebo" effect. In other words, parents and their children believe that the drink is helping them, regardless of whether it has the active ingredient, and therefore their behavior changes. Placebo effects are nothing to sneeze at; they are very real and more powerful than we realize.  At this point, the team might have concluded that omega-3s are not effective for reducing child behavior problems or that the other nutrients in the drink (e.g., vitamin D) affected behavior as much as omega-3s might. But wait, there's more.

Six months after the treatment finished, the research team conducted a follow-up with the families. They asked all the parents and their children to complete the same behavioral surveys. The behavioral problems for kids in the placebo group returned, while the kids in the omega-3 group continued to show declines in aggressive behaviors, anxiety and depressive behaviors, and antisocial behaviors. In fact, omega-3s caused a 41.6% reduction in externalizing behaviors (aggression, inattention, hyperactivity), and a 68.4% reduction in internalizing behaviors (anxiety, depression). Wow... but why? How?

It's still too soon to know. One potential pathway is through parent behavior. Remember that parents in the omega-3 group showed the only significant difference in behavior at the end of treatment. The behavioral questionnaires used in this study were originally designed to detect big differences in behavior between kids with and without mental health problems that warrant treatment. This means that the scales used may not have been able to detect subtle changes in behavior. But, if you have kids, or know any well, a small change in behavior can make a big difference in your day-to-day life. The authors explain in the article that they think some of the benefit of omega-3s was due to children showing slight improvements in behavior that led to less reactive and antisocial parent behavior, which then led to continued improvements in child behavior. In other words, omega-3 supplementation broke the cycle that so often occurs between parents and kids with behavior problems.

Another fascinating pathway has to do with the effect omega-3s have on the brain. Omega-3s are becoming a hot topic in neuroscience because they seem to promote neuroplasticity (growing new brain cells and connections between existing ones) and inhibit inflammation which can cause low mood, confusion, and fatigue. It's possible that the omega-3 supplement allowed a build-up of omega-3s in the body and the brain over a series of months which promoted better learning and behavioral control in the kids. Importantly, it may take months of regular supplementation to build up this store in the body, and even longer to see meaningful differences in behavior.

So should we start pumping omega-3s in drinking water? Not yet. Can we treat children's ADHD and anxiety with omega-3s? Definitely not. Should we eat more salmon and fewer steaks? Probably. I don't want to mislead you. The research in this area is promising but still very new, and there is a lot we don't know. For example, what is the optimal dose? How long should people take it? Is there such a thing as too much? What are omega-3s actually doing in our brain and body? Science will get us there eventually, but in the mean time, sushi anyone?

Raine, A., Portnoy, J., Liu, J., Mahoomed, T., & Hibbeln, J. R. (2015). Reduction in behavior problems with omega‐3 supplementation in children aged 8–16 years: a randomized, double‐blind, placebo‐controlled, stratified, parallel‐group trial. Journal of Child Psychology and Psychiatry, 56(5), 509-520.

Many thanks to unsplash for the gorgeous photos.