Breastfeeding improves brain development in infants, according to a new study.
Breastfeeding alone produced better brain development than a combination of breastfeeding and formula, which produced better development than formula alone, the study found.
Researchers from Brown University used specialised, baby-friendly magnetic resonance imaging (MRI) to look at the brain growth in a sample of children under the age of 4.
The research found that by age 2, babies who had been breastfed exclusively for at least three months had enhanced development in key parts of the brain compared to children who were fed formula exclusively or who were fed a combination of formula and breastmilk.
The extra growth was most pronounced in parts of the brain associated with language, emotional function, and cognition, the research showed.
Behavioural studies have previously associated breastfeeding with better cognitive outcomes in older adolescents and adults.
However, this is the first imaging study that looked for differences associated with breastfeeding in the brains of very young and healthy children, said Sean Deoni, assistant professor of engineering at Brown and the study's lead author.
"We wanted to see how early these changes in brain development actually occur. We show that they're there almost right off the bat," Deoni said.
Researchers used quiet MRI machines that image babies' brains as they sleep. The MRI technique Deoni has developed looks at the microstructure of the brain's white matter, the tissue that contains long nerve fibres and helps different parts of the brain communicate with each other.
Specifically, the technique looks for amounts of Melina, the fatty material that insulates nerve fibres and speeds electrical signals as they zip around the brain.
Deoni and his team looked at 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 they exclusively breastfed for at least three months, those fed a combination of breastmilk and formula, and those fed formula alone.
The study showed that the exclusively breastfed group had the fastest growth in myelinated white matter of the three groups, with the increase in white matter volume becoming substantial by age 2.
The group fed both breastmilk and formula had more growth than the exclusively formula-fed group, but less than the breastmilk-only group.
"We're finding the difference [in white matter growth] is on the order of 20 to 30 per cent, comparing the breastfed and the non-breastfed kids. I think it's astounding that you could have that much difference so early," said Deoni.
The findings will appear in the journal NeuroImage.
