美国国家公共电台 NPR Breast-Fed Kids May Be Less Hyper, But Not Necessarily Smarter, Study Finds（在线收听）

DAVID GREENE, HOST:

OK, so here's something we know. Breast-feeding has many health benefits for infants. But what we haven't been so sure about is whether breast milk can also help improve a kid's intelligence. NPR's Allison Aubrey reports on a new study that casts some doubt on the idea that mothers' milk can boost children's brain power.

(SOUNDBITE OF BABY CRYING)

ALLISON AUBREY, BYLINE: For moms of newborn babies, breast-feeding can feel like a full-time job.

YULIA RING: Oh, my goodness. Oh, my goodness. She's so hungry right now.

AUBREY: I met up with Yulia Ring (ph) as she was out for a stroll with her 10-week-old daughter. And as she peeled off to find a place to feed, she says she's committed to breast-feeding.

RING: It helps to improve her immune system. But also, like, it's good for the mom, too.

AUBREY: Ring is spot on. There's evidence that breast-feeding can lower a mother's risk of breast cancer. And pediatrician Ellie Erickson of Duke University says there are lots of benefits for babies.

ELLIE ERICKSON: There is a strong body of evidence to support that breast-feeding is one of the healthiest things that we can do to support children's immune system.

AUBREY: The American Academy of Pediatrics recommends that babies be exclusively breast-fed for about six months. But not all moms can do this. Sometimes it's an issue of milk supply or a medical condition.

ERICKSON: There are a number of reasons why some women are unable to breast-feed.

AUBREY: So if a baby is not breast-fed, is anything lost? A new study helps to answer that question, at least when it comes to kids' brain development.

Researchers followed 8,000 children in Ireland starting at birth. And what they found is that by age 5, kids from similar backgrounds scored about the same on cognitive tests, regardless of whether they were breast-fed. Study author Lisa-Christine Girard said the breast-fed kids scored a tad better on some standardized measures.

LISA-CHRISTINE GIRARD: But yet, it wasn't significant. It wasn't big enough to show a statistical significance.

AUBREY: Girard says her findings suggest that it's not breast-feeding on its own that boosts brain development. It's likely a whole range of other characteristics and habits that breast-feeding moms tend to share.

GIRARD: For example, mothers who breast-feed, they typically have higher levels of education. They're engaging in less risky prenatal behaviors. For example, they're not smoking during pregnancy.

AUBREY: And when she factored in those variables, the standalone effect of breast milk was greatly diminished. This new finding does not in any way alter the recommendation to breast-feed. But it does suggest that when it comes to shaping a kid's brain power, breast-feeding alone does not play a leading role. Allison Aubrey, NPR News.

(SOUNDBITE OF IZZARD'S "GHOST NAPS")