A new study suggests that breastfeeding alone results in better brain white matter development than a combination of breastfeeding and formula, or formula alone.
Researchers at Brown University (Providence, RI, USA) used quiet magnetic resonance imaging (MRI) machines to examine the microstructure of white matter myelin in 133 babies ranging in ages from 10 months to four years. All of the babies had normal gestation times, and all came from families with similar socioeconomic statuses. The researchers split the babies into three groups: those whose mothers reported exclusively breastfed for at least three months, those fed a combination of breastmilk and formula, and those fed formula alone. The researchers compared older children to younger ones to establish growth trajectories in white matter for each group.
The results showed that breastfed children exhibited increased white matter development in later maturing frontal brain regions. Positive relationships between white matter microstructure and breastfeeding duration were also exhibited in several brain regions, anatomically consistent with observed improvements in cognitive and behavioral performance measures. The researchers also tested a set of basic cognitive tests on the older children, finding increased language performance, visual reception, and motor control performance in the breastfed group.
“We’re finding the difference is on the order of 20 to 30 percent, comparing the breastfed and the nonbreastfed kids. I think it’s astounding that you could have that much difference so early,” said lead author assistant professor of engineering Sean Deoni, PhD. “While the mechanisms underlying these structural differences remains unclear, our findings provide new insight into the earliest developmental advantages associated with breastfeeding, and support the hypothesis that breast milk constituents promote healthy neural growth and white matter development.”
The prevailing consensus from large epidemiological studies posits that early exclusive breastfeeding is associated with improved measures of IQ and cognitive functioning in later childhood and adolescence. Prior morphometric brain imaging studies support these findings, revealing increased white matter and subcortical gray matter volume, and parietal lobe cortical thickness (associated with IQ), in adolescents who were breastfed as infants compared to those who were exclusively formula-fed.