Intake of fish oil during pregnancy and adiposity in 19-y-old offspring: follow-up on a randomized controlled trial

Background: It is well established that obesity tends to track from early childhood into adult life. Studies in experimental animals have suggested that changes in the peri-and early postnatal intake of n-3 (omega-3) polyunsaturated acids can affect the development of obesity in adult life. Objective: The aim of the current study was to investigate the effect of daily supplementation with 2.7 g long-chain n-3 fatty acids during the third trimester of pregnancy on adiposity in 19-y-old offspring. Design: The study was based on follow-up of a randomized controlled trial from 1990, in which 533 pregnant women were randomly assigned to receive fish oil, olive oil, or no oil. At similar to 19 y of age, the offspring of subjects from the randomized controlled trial were invited to undergo a physical examination, including anthropometric measurements and fasting blood sampling. The blood sample was analyzed for insulin, glucose, glycated hemoglobin, leptin, adiponectin, insulin-like growth factor I, and high-sensitivity C-reactive protein. Multiple linear regression modeling, adjusted for sex, smoking, and parental overweight, was used to estimate the effect of fish oil relative to that of olive oil on BMI (in kg/m(2)), waist circumference, and biochemical measures. Results: A total of 243 of the offspring were followed up. We found no difference between the fish-oil and olive oil groups in BMI (0.13; -0.92, 1.17) or waist circumference (0.7 cm; -2.1, 3.4 cm). Overall, results of the biochemical analyses supported the finding of no difference between the groups. Conclusion: We detected no effect of fish-oil supplementation during pregnancy on offspring adiposity in adolescence. Am J Clin Nutr 2011;94:701-8.