VISUAL AND NEURAL DEVELOPMENT OF BREAST–FED INFANTS RECEIVING DOCOSAHEXAENOIC ACID (DHA)–ENRICHED BABY FOOD: A RANDOMIZED CLINICAL TRIAL.

Abstract

Abstract: : Purpose: Breast–fed infants receive high levels of the omega–3 polyunsaturated fatty acid, DHA, from human milk but at 6 mo of age, the amount of DHA begins to diminish as the infant consumes baby food products. The purpose of the present study was to determine if providing DHA–enriched baby foods could improve the breast–fed infant’s blood DHA status as well as influence visual and neural development. Methods: In this double–blind clinical trial, breast–fed infants at 6 mo of age were randomized to receive one jar per day of baby food containing DHA–enriched egg yolk (110 mg DHA / 100 g food; n = 25) or control baby food (0 mg DHA; n = 26). Fatty acids in red blood cells (RBC) were measured by gas chromatography upon entry (6 mo) and exit (12 mo) from the dietary intervention period. At 6, 9, and 12 mo, visual acuity was determined by sweep visual–evoked potentials (VEP). At 9 mo, the infant’s cognitive skills were tested using a two–step problem–solving task. At 18 mo, neurodevelopmental milestones were assessed using the Bayley Scales of Infant Development. Results: The DHA content in RBCs at 6 mo (baseline) was not significantly different between diet groups (3.9% ± 0.1%; mean ± SE). By 12 mo, DHA levels dropped to 3.0% in the control group while there was a 44% increase to 5.6% in DHA–supplemented infants (p<0.0005). VEP acuity improved by 1.5 lines between 6 and 9 mo and another 2 lines by 12 mo compared to 0.5 and 1.5 lines in controls; the group difference at 12 mo was 1.5 lines (0.156 logMAR; p<0.0005). At 9 mo, infants receiving DHA–enriched baby foods had better scores on the two–step problem–solving test than controls (9.6 ± 0.9 vs. 6.3 ± 1.1; p=0.03). Although infants in the supplemented group had higher mental development scores (Bayley MDI scale) than controls, this difference was not statistically significant (107.6 ± 3.7 vs. 103.5 ± 1.9; p=0.29). RBC levels of DHA at 12 mo were correlated with VEP acuity at 9 mo and 12 mo (p <0.002) and with Bayley MDI scores at 18 mo (p=0.02), but only demonstrated a trend with two–step test scores at 9 mo (p=0.12). Conclusions: Overall, DHA supplementation of the infant’s baby food from 6 to 12 mo of age improved blood chemistry and is consistent with more mature visual and neural function during the critical developmental period of infancy. These data support the need for a continued supply of DHA in the infant’s diet through one year of life.

Keywords: visual development: infancy and childhood • nutritional factors • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials