A number of studies have reported similar results and this led to calls by some for omega-3 supplementation of school children. Indeed, the UK's Food Standards Agency (FSA) last year reviewed the science in this field but ultimately decided against such measures, stating the evidence was insufficient. In many cases these studies were said to lack quality in research methodology and reporting, and failed to account for confounders.
But studies like the controlled trial published in the Nutrition Journal could lead to a rethink in this stance.
The researchers, led by Barry Sears from the Inflammation Research Foundation, Massachusetts, supplemented nine ADHD children (aged 8 to 16) with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentrates (16.2 grams per day: 10.8g EPA, 5.4g DHA) for eight weeks.
At week four, the researchers adjusted the dosage was based on the arachidonic acid (AA):EPA: if the AA:EPA ratio was below 1.0, the daily dosage was reduced to 5.4g EPA, 2.7g DHA per day, and if the AA:EPA ratio was between 1.0 and 1.5 the dosage was cut to 8.1g EPA, 4g DHA.
At the end of the study, the researchers report that blood levels of EPA and DHA were significantly increased, the AA:EPA ratio in the plasma also improved, as did behaviour assessed by a psychiatrist.
"Although this was a small one-arm study, the results are encouraging as they suggest that high-dose EPA and DHA (up to 16.2g per day) can be given to children with good adherence," wrote the researchers.
"The inconsistent findings from previous studies and our results suggest that greater dosages of EPA are needed to decrease the AA:EPA ratio to levels similar to the Japanese population and to observe significant behavioural improvements.
"The preliminary results found in this pilot study warrant future randomized, placebo-controlled, double blind studies that use participant's AA:EPA ratios to determine EPA/DHA supplementation dosage for adjunct treatment of ADHD in children," they concluded.
The research is in-line with a randomised, double-blind, placebo-controlled trial from Australia, published in April, that showed that after 30 weeks of omega-3 supplementation parents rated significant improvements in ADHD-related symptoms of 132 children (Journal of Developmental & Behavioural Pediatrics, Vol. 28, p 82-91).
Source: Nutrition Journal
2007, 6:16, doi:10.1186/1475-2891-6-16
"Effects of an open-label pilot study with high-dose EPA/DHA concentrates on plasma phospholipids and behavior in children with attention deficit hyperactivity disorder"
Authors: P.J. Sorgi, E.M. Hallowell, H.L. Hutchins, B. Sears