RENEE MONTAGNE, HOST:
Babies who are breast-fed tend to be more successful in life. That's the provocative suggestion of a new study being published this week in The Lancet Global Health. The study took place in Brazil, where researchers say breast-feeding rates didn't vary much between women of different economic classes. NPR's health correspondent Rob Stein has the story.
ROB STEIN, BYLINE: Doctors have long known that breast-feeding is good for a baby's health. But Bernardo Horta of the Federal University of Pelotas in Brazil says there's a lot of debate about just how much of a difference breast-feeding makes in a child's life. So Horta and his colleagues took a look at more than 3,000 babies they've been following since they were born. They're now in their 30s. First, they gave them IQ tests.
BERNARDO HORTA: The subjects who were breast-fed for 12 months or more had a higher IQ than those who were breast-fed for less than one month. The difference in IQ was 3.76 points.
STEIN: That may not sound like a lot, but Horta and his colleagues didn't stop there. They also looked at how much education they'd gotten and how much money they were making.
HORTA: We also observed that they had a higher education, as well as a higher monthly income.
STEIN: They earned about a third more than those who got little or no breast-feeding as babies.
HORTA: Breast-feeding is - not only has short-term benefits, but also breast-feeding has long-term benefits, improving the performance and intelligence in adulthood, as well as the income - OK? - the economic productivity.
STEIN: Other researchers praise the study.
RUTH LAWRENCE: I think it's a remarkable study, actually.
STEIN: Ruth Lawrence is a professor of pediatrics, obstetrics and gynecology at the University of Rochester.
LAWRENCE: This proves the permanency of these effects, which are very important, I think, to establish the critical impact of breast-feeding on a child's potential. And it gets into, you know, what are you going to do for the rest of your life, and how much money are you going to make doing it?
STEIN: But other researchers are more cautious. Valerie Flaherman of the University of California in San Francisco says lots of factors influence intelligence and success in life.
VALERIE FLAHERMAN: There's the potential for people to think if you don't breast-feed, your baby will be stupid or mentally impaired or something like that. While it's a potential benefit, it's one factor among many that mothers should consider in their decision.
STEIN: Many women can't breast-feed for physical reasons or because they have to go back to work. And Flaherman worries that women are already being stigmatized if they use formula.
FLAHERMAN: I do worry that sometimes when mothers hear about projects like this, they feel guilty when they were not able to breast-feed their babies. And what I hear from some of my mothers is that, you know, if they are giving their baby a bottle in Starbucks or on the bus or something, they feel like people are giving them dirty looks or saying they should be breast-feeding. So I think that can be a problem for mothers and babies.
STEIN: Horta and Lawrence agree that babies raised on formula can turn out to be just fine, but they say everything should be done to help women breast-feed if they can. Rob Stein, NPR News.
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