Breastfed babies may become smarter teens
- Friday, June 26th, 2009
A number of studies have linked breastfeeding to higher childhood IQ, but questions remain about whether the benefit comes from breast milk, per se. Mothers who choose to breastfeed may, for instance, be more educated, have higher IQs or provide a generally more stimulating environment for their babies.
The new study, based on a national survey of U.S. high school students and their parents, included 191 sibling pairs in which one had been breastfed and one had been formula-fed.
Comparing such siblings helps control for hard-to-measure factors, like parents' intelligence and the family environment that may account for the link between breastfeeding and school performance.
The researchers found that even between siblings, breastfeeding did appear to make a difference. On average, breastfed siblings had a 12 percent to 14 percent higher grade point average (GPA) in high school, and were somewhat more likely to go to college.
What's more, GPA tended to inch upward with each additional month of breastfeeding, as did the odds of attending college, according to findings published in the Journal of Human Capital.
Much of the connection seemed to be explained by higher intelligence scores and better physical health among teenagers who had been breastfed.
"Our results suggest that there are two important pathways through which breastfeeding may affect educational attainment -- through improvements in cognitive ability and health," Joseph J. Sabia, one of the researchers on the work, told Reuters Health.
"In fact, we find that approximately half of the effect of breastfeeding on high school grades can be explained by these factors," said Sabia, a professor of public policy at American University in Washington, D.C.
However, he added, this study is "just a start," and more research is needed to confirm that breastfeeding itself does in fact benefit children's school performance.
Researchers speculate that if breastfeeding does boost later intelligence, it is likely related to particular fatty acids found in breast milk that aid brain and nervous system development.
In general, experts recommend that infants ideally be breastfed for at least the first year of life, with breast milk as the sole food for the first 6 months.
Sabia said he thinks parents should consider the possible impact on school achievement when making breastfeeding decisions.