By Matthew Lin and Shaidah Deghan, MSc.
Study Rundown: Asthma is a chronic disease that affects approximately 20% of young children, with the cost of care for these patients between 2005 and 2009 estimated as a little over $10 billion. The association between poor prenatal intake of n-3 LCPUFAs and increased risk of asthma in offspring has been suggested by observational studies, but randomized controlled trials have offered mixed results. In the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC), researchers aimed to determine if supplementation of n-3 LCPUFAs in pregnant women during their trimester would reduce the risk of asthma in their offspring up to 5 years of age. The results demonstrated that third trimester n-3 LCPUFA supplementation reduced the absolute risk of asthma and LRTI (i.e. bronchitis, pneumonia) in offspring. Specifically, the risk of asthma in offspring was reduced by 6%, and this effect was most pronounced in women with low pre-study levels of omega-3 fatty acids. The number needed to treat to prevent one case of asthma was 14.6 in the total cohort. Overall, the trial is well-powered with good longitudinal follow-up but with some recruitment bias (participants vs. nonparticipants differed in employment and income level). The clinical implications of this study suggests that prenatal supplementation with n-3 LCPUFAs may contribute to the prevention of asthma and respiratory infections in young children.