EPA/DHA Supplementation Found to Improve Working Memory Function in Children with ADHD
Widenhorn-Muller, K. et al., Prostaglandins , Leukotrienes and Essential Fatty Acids, 91: 49-60, 2014
Transfer Ctr. For Neuroscience and Learning, University Hospital, Ulm, Germany
Attention deficit/hyperactivity disorder (ADHD) is a developmental childhood disorder characterized by the inability for sustained concentration and adherence to assignments and controlling impulsive and hyperactive behavior. Children with ADHD have often been found to have lower circulating blood levels of EPA/DHA as compared to healthy controls. Previous intervention trials in children with ADHD have yielded somewhat inconsistent results. The present trial was designed to evaluate if cognitive impairments and behavioral symptoms in children aged 6-12 years of age could be modified via EPA plus DHA supplementation.
Of 110 children diagnosed with ADHD, 55 were randomly assigned to receive 720 milligrams (mgs) of supplemental EPA plus DHA daily (600 mgs as EPA plus 120 mgs as DHA) for 16 weeks while 55 (control group) were assigned to receive a ‘placebo’ (olive oil) devoid of EPA/DHA. Various measures of parent- and teacher-rated behavior (including attention, hyperactivity, impulsivity, aggressiveness , anxiety , depression ,others) were conducted at baseline entry and after 16 weeks of supplementation. A psychologist performed cognitive assessments and behavioral ratings before and after the intervention with supplementation.
As expected, the EPA and DHA levels in the red blood cells from the children taking the EPA/DHA supplement, but not the placebo, rose dramatically after the 16-week intervention. Teacher- and parent-rated attention, hyperactivity, impulsivity, hyperactivity/impulsivity, and total behavior scores did not change significantly over the 16 week intervention period. However, for cognitive functioning, a significant improvement of working memory function (Index Score) was found when comparing the EPA/DHA group with the placebo group. Analyses of the working memory subtest and task performance revealed a significant improvement for the Digit Span subtest (by 13 % overall) and for the Digits Backward task (by 17 % overall) for the group of children assigned to the EPA/DHA supplementation. The Digit Span testing involved having the child to repeat numbers in the same order as read by the examiner or by a reverse order. The authors concluded ‘that the used EPA/DHA supplement leads to improved working memory function in the study population’.
Based on published reports of dietary EPA/DHA intakes in adults/children from North America or certain European countries, it is apparent that the intake of EPA/DHA via supplementation in the present study was many-fold higher than typically consumed. However, combined EPA/DHA intakes of 400-500 mgs/day are commonplace amongst many Japanese schoolchildren. While this study was conducted in children with ADHD, it is possible that the benefits seen with EPA/DHA on working memory function may occur in other children who do not have ADHD. Thus, future well-controlled trials in children of varying ages and backgrounds along the lines of the present design should be encouraged.