There are a number of studies which show that breastfed infants develop superior brain function, including IQ scores, than those not breastfed.

It has never been easy, however, to be certain whether this is due to some intrinsic benefit of breast milk or simply a reflection of other factors: those that influence whether a child is breastfed, such as mother's level of education and the like.

A new study from UK and US researchers helps answer this question. A feeding trial was used to calculate the proportion of breast milk in the diets of 50 adolescents when they were infants. MRI scans of the adolescent participants were used to find total brain matter and the relative proportions of grey and white matter. They also carried out various IQ tests.

The researchers found that the proportion of breast milk in the diet as an infant was correlated with verbal IQ in boy and girls at adolescence. A higher proportion of breast milk was also related to all IQ scores, higher total brain volume and white matter volume in boys.

Verbal IQ was in turn correlated with white matter volume and, in boys, also with total brain volume. Grey matter volume was, as expected, never significant as it is the non-nervous content of the brain.

This study shows for the first time that the changes attributed to breastfeeding are associated with physical differences in the brain structure and size – particularly white matter growth. However, it still does not tell us whether these differences are directly caused by human breast milk or are a reflection of familial factors.

Source: Isaacs EB, et al. Pediatr Res 2009 Dec 22. [Epub ahead of print].

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Originally posted in March 2010. everybody Nutrition News items are selected from a wide range of journals, bulletins and nutrition information sources worldwide and summarised by Professor John Birkbeck, Institute of Food Nutrition and Human Health, Massey University. The opinions contained herein are those of the author and not necessarily those of the publisher or sponsor. Copyright UBM Medica (NZ) Ltd.