Effects of preterm infant formula supplementation with alpha-linolenic acid with a linolete/alpha-linolenate ratio of 6: a multicentric study

Objective: To investigate the effects of a milk formula supplemented with a alpha-linolenic acid (ALA) (18:2 n-6/18:3 n-3 ratio near 6/1) on plasma and red blood cell (RBC) fatty acids (FAs) in premature infants and compare with a non supplemented formula (18:2 n-6/18:3 n-3 = 22/1). Design and subjects: Infants of mothers who elected not to breast-feed were randomly assigned to either a high alpha linolenic formula (HLF: n = 31) group or a low alpha-linolenic formula (LLF: n = 32) control group. Infants fed human milk (HM: n = 25) were enrolled concurrently as a reference group. Anthropometric and biological measurements were made after two days (D2) and 15d(D15) of enteral feeding and at the 37th week (W37) of postconceptual age. In HLF, the 18:3 n-3 content was 1.95% of total FAs (0.77% of total energy) and the 18:2 n-6/18:3 n-3 ratio was near 6/1. In LLF, the 18:3 n-3 content was 0.55% of total FAs (0.22% of total energy) and the 18:2 n-6/18:3 n-3 ratio was 22/1. Results: ALA supplementation had minimal effect on the n-6 series, did not alter the anthropometric data and confirmed the conversion of ALA into docosahexaenaic acid (DHA). Throughout the study, it maintained, the RBC membrane DHA values within the confidence interval of those obtained in the HM group. Such was not the case with LLF. Conclusion: alpha-linolenic acid supplementation (from Rapeseed oil and in a 18:2 n-6/18:3 n-3 ratio=6) in premature infant formula can contribute efficiently to the maintenance of the n-3 status in the premature newborns.