Breastfeeding Builds Smarter Kids
March 20, 2002 -- The benefits of breastfeeding continue to pour in. A new study finds that full-term babies who are born small -- weighing less than 6 pounds -- score 11 points higher on IQ tests taken at 5 years old if they are breastfed for their first 6 months. Those infants also reach normal size faster than babies on formula.
Previous studies have shown that breastfeeding helps infants' brain development if they are born preterm or are normal size at birth. This study broadens that scope even further.
"Our findings suggest that, whenever possible, exclusive breastfeeding for the first 24 weeks of life is the method of choice to enhance children's [brain] development," says lead author Malla Rao, an epidemiologist with the National Institute of Child Health and Human Development, in a news release. His study is published in the March Acta Paediatrica.
Rao's study should be encouraging for new mothers, says Ruth Lawrence, MD, professor of pediatrics at the University of Rochester School of Medicine. Lawrence, who is a spokeswoman for the American Academy of Pediatrics, reviewed the study for WebMD.
"Small babies feed very poorly initially," she tells WebMD. "It's reassuring to know that breastfeeding is worth the effort, that it has a significant advantage to these [small babies' brains]. It's also good news that the babies did so well on the growth curve. If breastfeeding were not adequate, a small baby that started compromised would remain compromised."
About 10% of all full-term babies in the U.S. weigh less than 6 pounds. Studies have shown that small-sized infants have poor academic performance and long-term achievements than those born at normal size, writes Rao.
However, little has been known about the effect of breastfeeding on these babies' brain development.
The current study takes place in Norway and Sweden, where mothers exclusively breastfeed their infants longer than U.S. mothers. In the U.S., 21% of infants get breast milk for 4 months, and only 16% are breastfed until they are 6 months old.
Researchers analyzed data on 220 full-term, small-size babies who were otherwise normal -- that is, they had no birth abnormalities. They were compared with 299 full-term, normal-size babies.
Physicians evaluated the children at birth, at 6 weeks old, and at 3, 6, 9, and 13 months of age. At each visit, their mothers were asked whether they had fed their children formula, milk, cereal, or other solids. They were also asked the age at which the foods were given.
At 13 months old, the children's muscle coordination and mental abilities were tested. When the children reached age 5, they were given IQ tests.
Those children who were small-sized at birth -- and who were breastfed exclusively for the first 24 weeks -- had 11-point-higher IQ scores at age 5 than did similar children who were given supplements. The breast-fed babies had also caught up with normal kids in their growth.
Children who were breastfed for just 12 weeks did not have such high IQ scores.
The study also puts to rest a widely held belief that supplementary feedings of formula or cereal -- in addition to breast milk -- will help smaller infants reach normal size faster than they would on breast milk alone, says Rao.
"Exclusive breastfeeding does not appear to hinder the growth of small-size infants," Rao says.