n-3 fatty acid status, behaviour, school performance and well-being in children with attention-deficit hyperactivity disorder (ADHD): OPUS school meal study: a case-control study of children with ADHD and healthy children

Background: n-3 polyunsaturated fatty acids (PUFA) including docosahexaenoic acid (DHA) are major components of neuronal membranes and are critical for normal brain development and function. Increasing evidence suggest that a lack of n-3 PUFA may contribute to psychiatric and neurodevelopmental disorders such as attention-deficit hyperactivity disorder (ADHD). Animal n-3 PUFA dietary restriction studies have observed increased locomotor hyperactivity and reduced cognitive function. Several human observational studies have reported lower n-3 PUFA levels in individuals with ADHD. However, human intervention studies show inconsistent results in demonstrating treatment effect of n-3 LCPUFA in individuals with ADHD. Objective: To investigate if children with ADHD differed from healthy controls and whether intake of fish or fish oil influenced ADHD related symptoms. Furthermore, to see if the association between DHA status and ADHD related symptoms also were present in a larger group of healthy children. Material and method: Using baseline data from the OPUS School Meal Study, fifteen children diagnosed with ADHD and forty-five matched controls were analyzed for difference in dietary pattern, blood fatty acid composition, attention, school performance, well-being, physical activity level and sleep pattern. Furthermore children within the ADHD group was analyzed for difference dependent on whether the children did or did not receive medication and/or fish oil in order to investigate if supplementation was associated to improved attention and reduced hyperactivity. Finally, a correlation analysis between DHA blood level, attention and physical activity in a larger group of healthy children was performed. Results: The ADHD group was presented with higher EPA blood levels (p=0.01), lower total n-6 PUFA blood levels (p=0.05) and lower n-6/n-3 PUFA ratio (p=0.04) compared to controls. Children with ADHD consumed equivalent amount of fish but more received fish oil