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 United States do not contain ω3 and ω6 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 need for docosahexaenoic acid and arachidonic acid supplementation in the infant diet was evaluated in a double‐blind, randomized clinical trial. Methods Healthy term infants were randomized to diets of (1) commercial formula, (2) docosahexaenoic acid–enriched formula (0.35% of total fatty acids), or (3) docosahexaenoic acid– (0.36%) and arachidonic acid– (0.72%) enriched formula. Eighty‐seven infants completed the 17‐week nutritional trial, and 58 were observed until 52 weeks of life. A reference group was exclusively breast fed for at least 17 weeks (n = 29). Outcome measures included electroretinographic responses, visual evoked potentials, and blood fatty acid 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 docosahexaenoic acid in total red blood cell lipids during the 17‐week feeding trial compared with breast‐fed infants. Significant differences persisted at the 1‐year follow‐up. Arachidonic acid content was consistently reduced in the commercial formula group by 15% to 20%. Infants fed long‐chain polyunsaturated fatty acid–enriched formulas had docosahexaenoic acid and arachidonic acid blood lipid profiles resembling those of human milk‐fed infants. Infants receiving this enriched formula had more mature electroretinographic responses than commercial formula‐fed infants at 6 weeks of age. Human milk‐fed and docosahexaenoic acid‐enriched formula‐fed infants had better visual 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 with later (52‐week) visual function development in study infants. Conclusions Results from this clinical trial demonstrate that long‐chain polyunsaturated fatty acid supplementation of formula in term infants produces blood lipid fatty acid profiles that are similar to those observed in breast‐fed infants. This supplementation leads to better visual function later in life (i.e., 1 year of age) than that shown by infants fed commercial formula.