Investigators from several United States institutions conducted a double-blinded randomized placebo-controlled trial to evaluate the long-term health benefits of supplementing lactating mothers with 200 mg per day of DHA (docosahexaenoic acid) during the first four months postpartum. Two hundred twenty-seven pregnant women who planned to breastfeed exclusively for at least four months were assigned randomly in a double-blinded fashion to receive one of two identical capsules daily for four months, starting within five days after delivery. One of the capsules contained 200 mg of DHA; the control contained a 50:50 mixture of soy and corn oils. The mothers were between 18 and 40 years of age, infant gestational age was greater than 37 weeks, and infant birth weights were greater than 2,500 gm but less than 4,200 gm. A previous paper reported that the treated infants had no improvement in visual function at 4 and 8 months of age, no difference in neurodevelopment indexes at 12 months of age, and no difference in the Bayley Mental Developmental Index (MDI) at 30 months of age.1 However, treated infants had a significantly higher mean Bayley Psychomotor Development Index (PDI) at 30 months of age.
The current study reports five-year follow up of 119 of the original 227 infants. Again, there was no difference in visual function as assessed by the Bailey-Lovie acuity chart, transient visual evoked potential, or sweep visual evoked potential testing. Nor were there differences on measures of gross or fine motor development, perceptual/visual-motor development, verbal skills, or emerging executive function. However, children whose mothers received the DHA supplement performed significantly better on the Sustained Attention subtest of the Leiter International Performance Scale-Revised (46.5±8.9 vs 41.9±9.3; P=.008). This difference in attentiveness remained significant even after adjusting for confounding variables. However, the difference was only statistically significant for girls (50.5±9.1 vs 41.0±9.6; P=.001), but not for boys (43.8±7.8 vs 42.5±9.1; P=.55). There was no significant correlation between this attention score at 5 years of age and the Bayley PDI at 30 months of age. There also was no correlation between infant plasma DHA level at either 4 or 8 months of age, measures of visual function at 5 years of age, or neurodevelopmental status at 5 years of age.
The authors conclude that DHA supplementation of breastfeeding mothers confers long-term benefits on specific aspects of neurodevelopment.
Dr Noble has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.
DHA is the major omega-3 long chain polyunsaturated fatty acid (PUFA) in the brain and retina. As humans cannot synthesize DHA efficiently, it must be consumed in the diet. Therefore, DHA content...