"For women in developed countries who can achieve exclusive breast-feeding for at least three months, their kids would benefit by about three or four IQ points," he said.
One expert thinks it's the nutrients in mothers' milk -- which aren't found in other foods -- that are essential for brain development and increased IQ.
"I'm not surprised because many studies have had similar results," said Dr. Ruth Lawrence, a professor of pediatrics at the University of Rochester School of Medicine, and a member of the American Academy of Pediatrics executive committee section on breast-feeding. "It's wonderful to have this very large study to confirm what we've known or thought for a long time."
Lawrence thinks that because mothers' milk contains certain amino acids not found in formula, it's better for infants' developing brains. These amino acids include omega three fatty acids and DHA (Docosahexaenoic acid), which are important for brain growth, she noted.
Human milk also contains cholesterol, while formula doesn't, Lawrence said. "We learned to fear cholesterol and yet cholesterol is very important for brain tissue, it's very important for nerve tissue," she said. "That's why human milk is a better nutrient to support brain growth."
Many professional organizations, including the American Academy of Pediatrics, recommend breast-feeding as the best way to improve infants' overall health and build their immune system. Breast-fed infants have fewer hospital admissions, ear infections, diarrhea, rashes, allergies and other medical problems than bottle-fed babies, according to the U.S. Food and Drug Administration.
More information
To learn more about breast-feeding, visit the U.S. National Women's Health Information Center.
