Girl Babies Breathe Easiest When Breastfed

In a study designed to test the value of breastfeeding premature infants, researchers found a challenge to the common belief that all babies benefit equally from breastfeeding. The findings of the study, led by researchers at Johns Hopkins Children’s Center, show that girl babies who are breastfed suffer fewer and milder respiratory infections than girls who are fed formula and boys who are fed either breast milk or formula.

An international team of researchers followed 119 premature babies born in Buenos Aires for the first year of their lives. For research purposes, the babies were divided into four groups - girls fed formula, girls fed breast milk, boys fed formula, and boys fed breast milk. The June issue of the journal, Pediatrics, carries the full details of the study.

The research team discovered that the girls getting breastfed were less likely to develop respiratory infections and the infections they developed were less severe than those developed by the infants in the other groups. The girls who received formula were at the highest risk of developing respiratory infections while there was no difference in the rate of infection for the boys, regardless of which means of feeding they received.

This finding presents a challenge to the traditional understanding that chemicals in breast milk strengthen the immune systems of all babies, regardless of gender. Instead, Fernando Polack, MD, senior investigator for the study, and specialist on infectious disease at Hopkins Children’s Center, raises the possibility that breastfeeding doesn’t target lung infections alone but works like a switching mechanism for universal protection. Still unknown is why it seems easier to switch the immune protection on in girl babies than in boys.

The study showed that girls getting formula were eight times more likely to develop respiratory infections serious enough to require hospitalization than the girls who were breastfed. These same girls were more prone to developing infections than boys of either study group.

Of the breastfed girls, only two of 31 (6%) developed respiratory infections that required hospitalization, compared to 12 of 24 (50%) of the formula-fed girls. Of the boys, 18% from both groups, breast- and formula-fed, required hospitalization for acute respiratory disease. The risk for infection remained the same throughout the first year of the infants’ lives.

Researchers hope to unravel the mystery that triggers universal protection for breastfed babies and why it does so with such variability. Learning how to activate the mechanism in boys as well as girls could prove to be more powerful than vaccines in saving the lives of premature babies worldwide.

Vaccines are currently available against only two specific viruses and only in developed countries where affluence and access to medical care allow vaccination. Knowing how and why the protection from breastfeeding is activated may prove to be beneficial and economical in developing countries especially but may also encourage mothers everywhere to breastfeed as much as possible regardless of whether the child is born premature or full term, male or female.

Breastfeeding is known to improve the development of a child’s brain and enhances his or her general health. This means of feeding infants is thought to deliver the very best nutrition possible.

The National Institutes of Health funded the study which ran for 24 months at Fundacion INFANT in Buenos Aires.

Filed under: Children's Health, Diet, Lifestyle, Pregnancy, Prevention