Effects of long-chain polyunsaturated fatty acid supplementation of infant formula on cognition and behaviour at 9 years of age

Aim Long-chain polyunsaturated fatty acid (LCPUFA) supplementation of infant formula may have a beneficial effect on cognitive development. This study aimed to investigate the effect of LCPUFA formula supplementation primarily on cognition and secondarily on behaviour at age 9 years. Special attention was paid to the potentially modifying effect of maternal smoking during pregnancy. Method A double-blind, randomized control study was performed in two groups of healthy infants born at term: one group, constituting the control group, received standard formula (n=169) and another group received standard formula supplemented with LCPUFAs (n=146). A breastfed group (n=159) served as an additional reference. At 9 years of age, 72% of the children (control group: n=123; 71 males, 52 females; LCPUFA group: n=91; 42 males, 49 females; breastfed group: n=127, 64 males, 63 females) underwent extensive cognitive and behavioural testing. Results An interaction between infant nutrition and smoking during pregnancy was found. Among children exposed to smoking during pregnancy, LCPUFA supplementation was associated with higher mean verbal IQ scores (p=0.007) and learning and memory (p=0.006). Among children not exposed to smoking during pregnancy, LCPUFA supplementation was associated with lower mean verbal memory scores (p=0.003). Executive function scores were significantly lower in the LCPUFA-supplemented group than in the control group (p=0.001). Breastfeeding was associated with better performance on IQ (p=0.005). Interpretation No consistent beneficial effect of LCPUFA formula supplementation on cognitive development in term-born infants was found. The study confirmed that breastfeeding is associated with better cognition.