BACKGROUND: Omega-3 long-chain polyunsaturated fatty acid (n-3 LCPUFA) supplementation during infancy may reduce adult cardiovascular risk as observed in animals. We assessed the effect of n-3 LCPUFA supplementation in infancy on growth, body composition, and cardiometabolic risk factors at 5 years of age.
METHODS: Infants were randomly assigned to a daily supplement of n-3 LCPUFA or olive oil (control) from birth to 6 months (n = 420). Measurements included weight, length, cord blood adipokines at birth and anthropometry, skinfolds, blood pressure, heart rate, fasting blood adipokines, and biochemistry at 5 years.
RESULTS: The infants who received n-3 LCPUFA had a smaller waist circumference at 5 years (coefficient: 1.1 cm; 95% confidence interval [CI]: 0.01 to 2.14), which remained significant after adjustments for confounders (coefficient: 0.8 cm; 95% CI: 0.19 to 1.30). Five-year-old boys who received n-3 LCPUFA supplementation as infants had a 21% reduction in insulin concentrations (ratio: 0.79; 95% CI: 0.66 to 0.94) and a 22% reduction in insulin resistance (ratio: 0.78; 95% CI: 0.64 to 0.95) compared with the control group. There were no other differences in growth and cardiometabolic risk factors between the groups for the whole cohort at birth, 2.5, or 5 years.
CONCLUSIONS: Supplementation with n-3 LCPUFA in infancy revealed a reduction in waist circumference at 5 years. Boys in the n-3 LCPUFA group showed reduced insulin concentrations and insulin resistance at 5 years, which may have beneficial outcomes for later health. No effects were seen in girls. Longer term follow-up of the cohort is warranted to determine whether these differences are maintained into adolescence.