Omega-3 supplementation during the first 5 years of life and later academic performance : a randomised controlled trial

Background/objectives: Consumption of oily fish more than once per week has been shown to improve cognitive outcomes in children. However, it is unknown whether similar benefits can be achieved by long-term omega-3 fatty acid supplementation. The objective was to investigate the effect of omega-3 fatty acid supplementation during the first 5 years of life on subsequent academic performance in children by conducting a secondary analysis of the CAPS (Childhood Asthma Prevention Study).Subjects/methods: A total of 616 infants with a family history of asthma were randomised to receive tuna fish oil (high in long-chain omega-3 fatty acids, active) or Sunola oil (low in omega-3 fatty acids, control) from the time breastfeeding ceased or at the age of 6 months until the age of 5 years. Academic performance was measured by a nationally standardised assessment of literacy and numeracy (National Assessment Program Literacy and Numeracy (NAPLAN)) in school years 3, 5, 7 and 9. Plasma omega-3 fatty acid levels were measured at regular intervals until 8 years of age. Between-group differences in test scores, adjusted for maternal age, birth weight and maternal education, were estimated using mixed-model regression. Results: Among 239 children, there were no significant differences in NAPLAN scores between active and control groups. However, at 8 years, the proportion of omega-3 fatty acid in plasma was positively associated with the NAPLAN score (0.13 s.d. unit increase in score per 1% absolute increase in plasma omega-3 fatty acid (95% CI 0.03, 0.23)).Conclusions: Our findings do not support the practice of supplementing omega-3 fatty acids in the diet of young children to improve academic outcomes. Further exploration is needed to understand the association between plasma omega-3 fatty acid levels at 8 years and academic performance.