Breastfeeding makes children smarter?

Breastfeeding exclusively for at least the first 3 months of life, as opposed to exclusively formula feeding or using a combination of breast milk and formula, seems to make children smarter, and the differences are clear much earlier than previously thought, according to a recent cross-sectional study.

Previous studies have indicated that adolescents who were breastfed as infants have greater white matter and subcortical gray matter volumes and greater parietal lobe cortical thickness-all associated with higher IQ-than those who were fed formula as babies. However, this latest study demonstrates differences in the brain as early as 2 years of age.

Researchers from Brown University used special, quiet, magnetic resonance imaging machines to take pictures of babies’ brains while they slept. They compared measures of white matter microstructure, specifically myelin, the fatty substance that insulates nerve fibers and facilitates the fast travel of electrical signals around the brain. Well-myelinated nerves deliver messages much faster than poorly myelinated nerves.

The investigators included 133 healthy children aged 10 months to 4 years. The children were either exclusively breastfed a minimum of 3 months; exclusively formula-fed; or were fed both formula and breast milk. All the babies had normal gestation times, and all came from families with similar socioeconomic statuses.

The researchers found that the exclusively breastfed children already showed increased white matter development, particularly in regions of the brain associated with language, emotional function, and cognition. The differences were on the order of 20% to 30% between the exclusively breastfed and the exclusively formula-fed groups.

They also found that in certain areas of the brain those who were breastfed the longest had the greatest white matter development, and that those areas with the greatest white matter development matched observed improvements in cognitive and behavioral performance measures. Specifically, those babies breastfed for more than 1 year had significantly enhanced brain growth, particularly in areas associated with motor function, compared with babies breastfed for less than 1 year.

The researchers were unsure of the mechanisms behind their findings.