Impact of early dietary intake and blood lipid composition of long-chain polyunsaturated fatty acids on later visual development

Background: In contrast to human milk, current infant formulas in the Unite d States do not contain omega3 and omega6 long-chain polyunsaturated fatty acids. This may lead to suboptimal blood lipid fatty acid profiles and to a measurable diminution of visual function in developing term infants. The n eed for docosahexaenoic acid and arachidonic acid supplementation in the in fant diet was evaluated in a double-blind, randomized clinical trial. Methods: Healthy term infants were randomized to diets of (1) commercial fo rmula, (2) docosahexaenoic acid-enriched formula (0.35% of total fatty acid s), or (3) docosahexaenoic acid-(0.36%) and arachidonic acid- (0.72%) enric hed formula. Eighty-seven infants completed the 17-week nutritional trial, and 58 were observed until 52 weeks of life. A reference group was exclusiv ely breast fed for at least 17 weeks (n = 29). Outcome measures included el ectroretinographic responses, visual evoked potentials, and blood fatty aci d analysis in infants at birth and at 6, 17, and 52 weeks of age. Results: Commercial formula-fed infants had 30% to 50% lower content of doc osahexaenoic acid in total red blood cell lipids during the 17-week feeding trial compared with breast-fed infants. Significant differences persisted at the I-year follow-up. Arachidonic acid content was consistently reduced in the commercial formula group by 15% to 20%. Infants fed long-chain polyu nsaturated fatty acid-enriched formulas had docosahexaenoic acid and arachi donic acid blood lipid profiles resembling those of human milk-fed infants. Infants receiving this enriched formula had more mature electroretinograph ic responses than commercial formula-fed infants at 6 weeks of age. Human m ilk-fed and docosahexaenoic acid-enriched formula-fed infants had better vi sual acuity than commercial formula-fed infants at both 17 and 52 weeks of age. Early (17-week) fatty acid profiles in blood lipids were correlated wi th later (52-week) visual function development in study infants. Conclusions: Results from this clinical trial demonstrate that long-chain p olyunsaturated fatty acid supplementation of formula in term infants produc es blood lipid fatty acid profiles that are similar to those observed in br east-fed infants. This supplementation leads to better visual function late r in life (i.e., 1 year of age) than that shown by infants fed commercial f ormula.