Babies who were breastfed have higher IQs, and they are less likely to develop behavioral problems and learning difficulties as they grow older. Studies indicate that babies who were breastfed outperform those who were bottle-fed in intelligence tests at age 3 years and even into adolescence.
Scientists have attributed this advantage to the high levels of nutrients in mother’s milk, particularly protein and omega-3 fatty acids. But now researchers are reporting that breastfeeding also promotes brain growth, possibly by promoting the development of white matter in the brain.
The scientists used quiet magnetic resonance imaging (MRI) to monitor the brains of 133 babies during their sleep. The MRI scans revealed that the children who had been exclusively breastfed for three months had more myelination in areas of their brain associated with thinking and memory, compared to those who were breastfed only briefly or formula-fed. The findings were published in the journal Pediatrics.
For the study, the scientists examined the MRI results of 77 healthy full-term infants and 78 premature babies born at 23 to 26 weeks gestation, who had been cared for in the neonatal intensive care unit. The researchers did not distinguish between the babies’ mothers’ breast milk and formula milk, as they wanted to see if all breastfeeding would have the same effect.
Earlier observational studies of breastfeeding have reported positive associations with child IQ, but these effects are difficult to isolate from confounding factors such as the maternal IQ. However, a large randomized trial that controlled for the mothers’ IQ has reported persistent and attenuated benefits of breastfeeding on child IQ, particularly verbal IQ.