Breastfeeding for Longer Periods Said to Increase IQ
Aug. 30, 2001 -- If milk does a body good, breast milk makes a baby smart.
That's the conclusion of a study of 345 Scandinavian children and their mothers. Babies who were breastfed for more than six months scored higher on intelligence tests given at 13 months and again at age 5 than babies breastfed for less than three months.
Breast milk is already credited with the ability to boost a baby's developing immune system, protect babies from infections, and reduce the risk for diseases like diabetes. Because breast milk is easier on the baby's digestive tract than packaged formulas, breastfed babies are also less likely to be colicky.
Norwegian pediatrician Thorstein Vik, MD, PhD, says that he thinks "essential fatty acids and growth factors" contained in human milk may explain the IQ advantage he found in his study. Vik is with the department of community medicine at Norwegian University of Science and Technology in Trondheim, Norway.
Carol Huotare, a board-certified lactation consultant and spokeswoman for the breastfeeding advocacy group La Leche League International in Schaumburg, Ill., agrees that it is probably nutrition, not nurturing, that explains the breast milk-intelligence link. For example, formula makers are now adding fatty acids found in breast milk to their products.
But Vik and Huotare both say that the strong bond that forms between a mother and a breastfeeding infant probably also helps a child's cognitive development.
Whatever the explanation, Vik says the IQ advantage is clear and says that even when other factors like the mother's age, intelligence, education, and smoking are factored in, duration of breastfeeding tips the IQ scale. He reports his findings in the British medical journal Archives of Disease in Childhood.
For breastfeeding proponents like Huotare, the new study is just one more piece of evidence to be used in the campaign to encourage American women to breastfeed their babies. In Scandinavian countries breastfeeding is the norm, but in the U.S. only about two-thirds of women try breastfeeding right after delivery, and six weeks later only about a third of women are still breastfeeding.
So breastfeeding advocate Kenneth Johnson, DO, director of the Women's Health Center at Nova Southeastern College of Osteopathic Medicine in Ft. Lauderdale, Fla., says he doesn't want women to think that breastfeeding for less than three months has no benefits. "The brain is one of the last organs to complete development. It makes sense that the longer the exposure to breast milk, the greater the cognitive advantage," he tells WebMD. "But I want women to understand that any amount of breastfeeding, even just a day or a week, will benefit their babies."
In the Scandinavian study, all the mothers had one or two older children, but the researchers didn't collect information on the older children.
"While breast milk does appear to confer an intelligence advantage, it is not the only factor influencing intelligence. Heredity and environment are both important factors in cognitive development, " Vik says.