Raine A, Portnoy J, Liu J, Mahoomed T, Hibbeln J. Reduction in behavior problems with omega-3 supplementation in children aged 8-16 years: a randomized, double-blind, placebo-controlled, stratified, parallel-group trial. J Child Psychol Psychiatry. 2014 Aug 22. [Epub ahead of print]
Randomized, double-blind, placebo-controlled, stratified, parallel-group trial: A community sample of children aged 8 years to 16 years of age were randomized into a treatment group (n=100) or placebo control group (n=100). Children were given a fruit drink containing 1 g daily of omega-3 fatty acids (treatment group) or no added omega-3s (placebo). The omega-3s in the drink consisted of 300 mg docosahexaenoic acid, 200 mg eicosapentaenoic acid, 400 mg alpha-linolenic acid, and 100 mg of docosapentaenoic acid. Treatment lasted for 6 months, and participants were followed for another 6 months after discontinuation of treatment.
Primary outcome measures were externalizing behavior problems that included aggressive behavior and secondary outcome measures that included parental-aggressive and psychopathic behavior as well as internalizing behavior problems. Child behavior was assessed by 2 parent reports—a child behavior checklist and antisocial personality screening device—plus a self-report and a reactive-proactive aggression questionnaire completed by the children. Parents completed a self-assessment psychopathic personality inventory. All psychometric instruments used have been validated in previous studies.
While children’s self-reports of behavior did not show improvements in the treatment group with the exceptions of reactive (P<0.0001), proactive (P=0.02), and total aggression (P<0.001), parents reported a significant improvement in children’s behavior in the treatment group for all internalizing and externalizing subscales evaluated, except somatic complaints.
Omega-3 supplementation for 6 months resulted in a 41.6% reduction in parent-rated child externalizing behavior measured 6 months after the treatment period had ended. A similar reduction (68.4%) was seen for internalizing behavior on the same time scale. The significance of these findings remained even when researchers controlled for parental belief in treatment allocation, which they did to remove any influence of placebo effects.
Interestingly, parents whose children took omega-3s showed significant posttreatment reductions in their own antisocial and aggressive behavior. Further analysis found that improvement in child behavior following treatment with omega-3s accounted for 38.7% of the improvement in parental antisocial behavior and that improvement in parental behavior accounted for 60.9% of the improvement in child behavior. Parental behavior may therefore partly account for the treatment effect on child behavior.
Limitations and Practice Implications
This study is interesting for several reasons. First, the effect of omega-3s on behavior has been studied but primarily on internalizing behavior such as depression. Studies on the effect of omega-3s on adolescents or children and externalizing behavior are few and have shown mixed results.1,2 One limitation of those studies is that they were performed with a short treatment and evaluation period, 15 weeks and 16 weeks, respectively. This is the first study where a longer treatment period was used and where subjects were monitored for extended periods posttreatment. It seems as though this longer period was required to evaluate the full effect of supplementation. While both the treatment and placebo groups reported some benefit during the treatment time (due to placebo effect or possibly due to additional vitamin D and antioxidants in the drink’s base), only the active treatment group maintained this improvement 6 months posttreatment.
While it does appear that omega-3 fatty acid supplementation had a clinical effect on child and adolescent externalizing behaviors, the majority of clinical improvement (as calculated by the study authors) could be attributed to a child’s response to changes in parental behavior.
Another interesting aspect to this trial is the lack of self-reported improvement in children compared to caregivers. This phenomenon has been observed in other studies, such as one study of young-adult prisoners in which self-reports failed to note behavioral improvements that were reported by observers.3 While this is the largest limitation to this study, most clinic visits to address children’s behavioral problems are made as a result of referrals from parents or other caregivers, which leaves these results still clinically relevant.
The most fascinating aspect of this study for me is the interesting effect of the parent on the child’s behavior and the child on parental behavior. This reinforces a clinical observation from my own experience when, during evaluation of a child with behavioral difficulties, it becomes clear to me that the parent-child dynamic may be contributing. This study clearly demonstrates that the answer is to address behavioral issues in any child both as an individual and as part of a family unit. While it does appear that omega-3 fatty acid supplementation had a clinical effect on child and adolescent externalizing behaviors, the majority of clinical improvement (as calculated by the study authors) could be attributed to a child’s response to changes in parental behavior. This parental behavior change was also largely attributable to a response in child’s behavior, thus indicating that the clinical benefit associated with omega-3 supplementation is only the tip of the iceberg: Clearly, it initiated a positive feedback loop in which the “treatment” was the relationship between caregiver and child. This study leaves me thinking of the sentiments of Bastyr University cofounder Bill Mitchell, ND, to “let people be medicine for one another” and feeling profoundly amazed that his idea could be proven, in this instance, within the confines of a randomized, double-blind, placebo-controlled study.