MR exams of infants and toddlers uncovered positive relationships between breastfeeding and white matter development. The exams also revealed a link between breastfeeding and development in brain regions associated with improvement in cognitive and behavioral performance measures, according to a study published online May 28 in NeuroImage.

Previous studies have observed that children who were breastfed perform, on average, higher on tests of IQ and cognitive functioning than those who were exclusively formula-fed, according to Sean C.L. Deoni, PhD, from the Advanced Baby Imaging Lab, School of Engineering at Brown University in Providence, R.I. However, imaging studies of breastfed children have focused on adolescents and gross morphometry.

Deoni and colleagues sought to examine early developmental differences related to neural growth or myelination. "We wanted to see how early these changes in brain development actually occur," Deoni said in a release. "We show that they're there almost right off the bat."

The researchers enrolled 133 toddlers and children, ages 10 months to 4 years and divided them into three groups: exclusively breastfed, exclusively formula-fed and those who were fed a mixture of breast milk and formula.

Parents completed a demographic interview and children were assessed via the Mullen Scales of Early Learning. The MR exams used the multicomponent relaxation MR approach, which provides a quantitative measure of myelin water fraction. Image data were mapped to a white matter mask.

By two years of age, babies who had been breastfed exclusively for at least three months had enhanced development in parts of the brain associated with language, emotional function and cognition compared to children who were fed formula exclusively or who were fed a combination of formula and breast milk. The extra growth was most pronounced in parts of the brain associated with language, emotional function and cognition, according to the researchers. In addition, “Behaviorally breastfed children showed improved receptive language scores compared to formula-fed children.”

Deoni et al cautioned that the cross-sectional study does not establish causation between breastfeeding, structural development and cognitive outcome. However, they stressed the findings reinforce the recommendation of the World Health Organization to breastfeed infants up to two years of age and beyond.