Confusion Lingers Over Breastfeeding and IQ
By Christine Cupaiuolo — December 11, 2006
“Decades of medical research prove that mother’s milk has extraordinary health benefits for babies. But does breast-feeding also make babies smarter, as some advocates claim?” asks Judith Graham of the Chicago Tribune.
The answer isn’t simple. Graham looks at a new study by three Scottish scientists whose findings on breastfeeding and intelligence was recently published in the British Medical Journal. The scientists found that “breast-fed children scored higher on measures of cognitive functioning than other kids. The gain was about 4 points; altogether, data for 5,475 U.S. children were analyzed. A combined ‘meta’ analysis of eight studies also was part of the report,” writes Graham.
Earlier research has pointed to the possible health value of mother’s milk itself — perhaps provided by “long-chain polyunsaturated fatty acids” — while other scientists have suggested that the bonding that occurs while breastfeeding might influence cognitive development. The most recent study points to a host of other factors.
[A]fter examining a host of potential influences, the Scottish scientists determined that the act of breast-feeding couldn’t explain why children performed better on tests of mental acuity. Instead, their analysis found that environmental and genetic factors explained higher scores for breast-fed children, especially the intelligence levels of mothers.
“Children who were breast-fed had mothers with higher IQ and with more education and who were older, less likely to be in poverty or to smoke and more likely to provide a more stimulating and supportive home environment,” the authors wrote. Because moms with higher IQs are more likely to breast-feed, breast-fed babies on average exhibit more cognitive competence than their bottle-fed counterparts, they suggest.
But that’s not the end of it. The findings have come under fire because the researchers didn’t create clear parameters defining which children were breastfed. “As a result, infants who were breast-fed exclusively were lumped in with babies who got very little mother’s milk,” writes Graham.
The study also relied on mothers’ memories (as many studies do) of how much and how often they breastfed. “It’s not easy to get accurate information when you’re doing recall interviews and when you’re lumping together any breast-feeding with exclusive breast-feeding,” said Dr. Cathy Spong, chief of the pregnancy and perinatology branch at the National Institute of Child Health and Human Development.
The story concludes with this reminder: “It’s almost always better to breast-feed, without exception, even though we don’t know all the answers to all the questions we have about its impact,” says Brenda Snyder, breast-feeding coordinator for the Illinois Department of Human Services.