Long chain omega-3 fatty acid intake in pregnancy and risk of type 1 diabetes in the offspring: Two large Scandinavian pregnancy cohorts -- MoBa and DNBC

Background Long-chain marine omega-3 fatty acids (eicosapentaenoic acid; EPA and docosahexaenoic acid; DHA) have anti-inflammatory effects. Dietary intake of EPA and DHA in pregnancy was associated with lower offspring risk of asthma in a randomized trial, and lower risk of type 1 diabetes in the offspring in retrospective observational studies. Aim We aimed to investigate whether higher intakes of EPA and DHA during pregnancy is associated with a lower type 1 diabetes risk in children in two of the world’s largest birth cohorts. Methods The Danish National Birth Cohort (DNBC) and the Norwegian Mother, Father and Child Cohort Study (MoBa) together include 153,843 mother-child pairs with prospectively collected data on EPA and DHA intake during pregnancy using validated food frequency questionnaires. Type 1 diabetes diagnosis in children (n=634) was ascertained from national diabetes registries. Results There was no association between the sum of EPA and DHA intake during pregnancy and offspring risk of type 1 diabetes (hazard ratio per g/d of intake: 1.00 in both MoBa and DNBC, pooled 95% CI: 0.88-1.14). Adjustment for potential cofounders and robustness analyses gave very similar results. Conclusion The hypothesis that a higher maternal omega-3 fatty acid intake during pregnancy reduce the risk of offspring type 1 diabetes was not supported.