Lucas A, Morley R, Cole TJ, Lister G, Leeson-Payne C.
MRC Dunn Nutrition Unit, Cambridge, UK.
There is considerable controversy over whether nutrition in early life has a long-term influence on neurodevelopment. We have shown previously that, in preterm infants, mother’s choice to provide breast milk was associated with higher developmental scores at 18 months. We now report data on intelligence quotient (IQ) in the same children seen at 7 1/2-8 years. IQ was assessed in 300 children with an abbreviated version of the Weschler Intelligence Scale for Children (revised Anglicised). Children who had consumed mother’s milk in the early weeks of life had a significantly higher IQ at 7 1/2-8 years than did those who received no maternal milk. An 8.3 point advantage (over half a standard deviation) in IQ remained even after adjustment for differences between groups in mother’s education and social class (p less than 0.0001). This advantage was associated with being fed mother’s milk by tube rather than with the process of breastfeeding. There was a dose-response relation between the proportion of mother’s milk in the diet and subsequent IQ. Children whose mothers chose to provide milk but failed to do so had the same IQ as those whose mothers elected not to provide breast milk. Although these results could be explained by differences between groups in parenting skills or genetic potential (even after adjustment for social and educational factors), our data point to a beneficial effect of human milk on neurodevelopment.
According to a recent article by Bradbury, the increased DHA (an omega-3 fatty acid found in seafood) content in the brains of breastfed infants may be responsible for the increase in IQ. Bradbury also referred to a study by Hibbeln, Maternal seafood consumption in pregnancy and neurodevelopmental outcomes in childhood (ALSPAC study): an observational cohort study. From it we learn:
After adjustment, maternal seafood intake during pregnancy of less than 340 g per week was associated with increased risk of their children being in the lowest quartile for verbal intelligence quotient (IQ) (no seafood consumption, odds ratio [OR] 1.48, 95% CI 1.16-1.90; some, 1.09, 0.92-1.29; overall trend, p=0.004), compared with mothers who consumed more than 340 g per week. Low maternal seafood intake was also associated with increased risk of suboptimum outcomes for prosocial behaviour, fine motor, communication, and social development scores. For each outcome measure, the lower the intake of seafood during pregnancy, the higher the risk of suboptimum developmental outcome.
To put it in plain English, the children of women who consumed no seafood during pregnancy had a nearly 50% greater chance than normal of ending up in the lowest IQ quartile. They used to say that fish was brain food, but this confirms that in spades.