Long-chain polyunsaturated fatty acids (LCPUFA) have been examined due to their potential to affect infant cognition (Long–chain polyunsaturated fatty acids, breastmilk … – gutsandgro). A recent meta-analysis has reviewed 19 studies with regard to LCPUFA supplementation and infant visual acuity (Pediatrics 2013; 131: e262-72 -thanks to Mike Hart for sharing this reference).
Since 75% of U.S. infants are formula fed by 1 year of age and there is widespread dependence on formula for nutritional completeness, these formulas have been designed to mimic breast milk composition. Docosahexaenoic acid (DHA) and arachidonic acid (ARA) are the two main LCPUFAs and are integral to the structural membranes of cells in the central nervous system and retina. DHA comprises >50% of the phospholipid content of the retinal membrane bilayer.
These 16 studies (in the abstract it erroneously states 19 studies), identified by a literature search, involved 1949 infants. Overall, a significant benefit of LCPUFA supplementation on infants’ visual acuity was noted at 2, 4, and 12 months of age when assessed by visual evoked potential. A benefit was also seen at 2 months of age by using behavioral methods. Studies were included if they were randomized control trials comparing LCPUFA supplementation to unsupplemented formula. Initially, 286 citations were identified but most did not meet inclusion criteria.
This study findings differ from two recent Cochrane reviews on the effect of LCPUFA on visual acuity. The Cochrane reviews failed to combine trials that measured “visual acuity in logMAR and cycles/degree and assessed preterm and term infants separately.” The authors state that this reduced the Cochrane reviews power to detect potential benefits of LCPUFA supplementation.
While this study demonstrates improvement during the first year of life, there is a scarcity of data beyond this time point. Limitations of this review included heterogeneity in the study results, varying doses of LCPUFA supplementation, variable DHA/AA ratio supplied, and variability in maternal diets.
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