Efficacy and safety of long-chain polyunsaturated fatty acid supplementation of infant-formula milk: a randomised trial

Background We tested whether addition of n-3 and n-6 long-chain polyunsatur ated fatty acids (LCPUFA) to infant-formula milk during the first 6 months promotes long-term cognitive and motor development, without adverse consequ ences. Methods We did a double-blind, randomised, controlled, efficacy and safety trial of formula with and without LCPUFAs, with an additional breastfed ref erence group, in four hospitals in two cities in the UK. The participants w ere 447 healthy full-term babies. 309 were fed formula (155 without LCPUFAs ) and 138 were breastfed for at least 6 weeks. The main outcome measures we re: Bayley Mental and Psychomotor Development Indices (MDI, PDI) at 18 mont hs (primary efficacy outcome) and Knobloch, Passamanick, and Sherrards test at 9 months (secondary outcome). Principal safety outcomes were: infection , atopy, growth, and gastrointestinal tolerance. Findings Babies fed formula with and without LCPUFA did not differ in cogni tive or motor development, growth, infection, atopy or tolerance. The mean (95% CI) MDI was 0.5 (-2.7 to 3.8) units and the PDI 0.6 (-1.8 to 3.0) unit s higher in the supplementation group. Formula-fed infants had similar deve lopmental scores to the breastfed reference group after adjustment for high er social class and maternal education in the latter. Interpretation There was no evidence of a beneficial or adverse effect on c ognitive and motor development or growth up to 18 months. Although no signi ficant differences in safety outcomes were observed, we suggest such data s hould be collected in future LCPUFA trials. Our trial does not provide supp ort for addition of LCPUFA to standard infant formula but we are now doing further follow-up of this cohort.