FRIDAY, July 18, 2008 (HealthDay News) -- Infants who are predominantly breast-fed for the first six months of life are less likely to have gastrointestinal problems. But, they're more likely to be deficient in iron, and therefore at risk of anemia, according to a study that looked at 154 mothers and their babies in Guadalajara, Mexico.
"We are verifying previous findings that in low-income countries, exclusively breast-fed infants are protected from GI [gastrointestinal] infection but appear to be at greater risk for iron deficiency," said Noreen Willows, an assistant professor at the University of Alberta in Edmonton, Canada, and the study's lead author.
Willows and her team compared a formula-fed group of about 50 babies with 55 partially breast-fed and 49 predominantly breast-fed infants from birth through six months, noting episodes of GI infections by asking the mothers about symptoms.
They took blood samples when the babies were 6 months old to check iron status. Mothers with poor maternal iron stores are more likely to have children with low iron stores.
Infants in the predominately breast-fed group had fewer GI infections; just 18 percent had GI infections during the study, compared to 33 percent of those partially breast-fed or formula-fed.
But the predominately breast-fed infants were more likely to have low iron levels. While just 4 percent of those in the partially breast-fed or formula-fed groups had iron deficiency, 22 percent of the mostly breast-fed babies did. It's known that total iron concentration in human milk is low. If the breast-feeding mother's iron stores are low to begin with, it can make the iron status problem worse. In Mexico, 28 percent of women have such low iron that they have anemia, the study authors said.
The study findings are published in the August issue of The Journal of Nutrition.
Despite the higher risk of iron deficiency and potential anemia, Willows said that the "breast-is-best" advice stands. Iron deficiency is generally correctable with supplements, she noted, while GI infections can be serious and even fatal.
The study results apply much more to women in underdeveloped countries than those in the United States, because fewer American women have low iron levels, said Dr. Ruth Lawrence, chairwoman of the section on breast-feeding at the American Academy of Pediatrics, and professor of pediatrics and obstetrics/gynecology at the University of Rochester School of Medicine, in New York.
Other studies have found that formula-fed babies have more gastrointestinal infections, she said.
Researchers have found that ''breast-fed babies don't become anemic if their cords are not cut too soon," Lawrence said. Delaying the cut for as little as two minutes can help improve the baby's iron status and confer other benefits, she added.
To learn more about breast-feeding, visit the U.S. Centers for Disease Control and Prevention.