Scientists Find More Evidence of Breast Milk's Goodness

TUESDAY, March 31, 2015 (HealthDay News) -- A high-tech comparison of the breast milk of humans and their close primate relatives is revealing just how nutritious the human variety is.

The research was led by Danielle Lemay, a nutritional biologist at the University of California, Davis' Genome Center. Her team used a new technique for identifying proteins found in breast milk.

The researchers found that human breast milk has far more protein content than the breast milk of one of humans' closest primate relatives, the rhesus macaque monkey.

"The higher levels of these proteins in human milk are consistent with the well-established perspective that human babies, compared to other primate infants, are born at a slightly earlier stage of development and require higher levels of specific proteins that will nurture them as they mature," Lemay said in a university news release.

In other words, human breast milk might be even more protein-rich because human babies rely on its nutritional benefits to a larger degree than other primates.

Lemay and her colleagues published the findings online this month in the Journal of Proteome Research.

The new research relies on a new means of molecular analysis that enabled the team to spot more than 1,600 distinct proteins in human milk, of which more than 500 were spotted for the first time.

This compared with just over 500 proteins found in rhesus macaque milk.

The breast milk of humans and rhesus monkeys also share 88 proteins in common, the team noted. However, 93 percent of those shared proteins were still found in higher quantities in human milk.

Some of those proteins aid in the digestion of fats, Lemay's team said, while others boost babies' ability to absorb iron and vitamins B-12 and D.

Current recommendations from the American Academy of Pediatrics urge women to breast-feed their baby exclusively for the first six months of life, and then combine breast milk and other foods until at least 12 months.

Going forward, Lemay suggested that "proteins that appear to have neurodevelopmental significance for human babies will be key targets for future research focused on enhancing infant formula."

More information

There's more on breast milk at the U.S. National Institute of Child Health and Human Development.