A new study shows that breastfeeding actually aids in the development of an infant's brain.

Researchers from Brown University used magnetic resonance imaging (MRI) to examine the brain growth in a sample of children under the age of 4. The research showed that children as young as 2 who had been breastfed exclusively for at least a three month period had enhanced development in key parts of the brain compared to children who were fed formula exclusively or who were only fed a combination of formula and breast milk. To add to that, the extra growth was shown to enhance part of the brain associated with language, emotional function and cognition, according to researchers.

However, scientists note that the health benefits of breast milk are nothing new. Behavioral studies have found that breastfeeding can result in better cognitive outcomes in older adolescents and adults. The study's lead author and an assistant professor of engineering at Brown, Sean Deoni, said that researchers looked for differences associated with breastfeeding in the brains of young and health children.

"We wanted to see how early these changes in brain development actually occur," Deoni said, according to a press release. "We show that they're there almost right off the bat."

Deoni and colleagues used quiet MRI machines to examine images of babies' brains while they slept. This gave researchers the chance to look at the brain's white matter, the tissue that contains long nerve fibers and helps various parts of the brain communicate with each other.

After looking at 133 babies ranging from 10 months to 4 years old, the study showed that those who were exclusively breastfed had the fastest growth in myelinated white matter than other groups. 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 percent, comparing the breastfed and the non-breastfed kids," said Deoni. "I think it's astounding that you could have that much difference so early."

The findings for the study are available online in the journal NeuroImage.