THURSDAY, Nov. 5, 2015 (HealthDay News) -- Breast-fed children are just as likely to develop allergies as children who were formula-fed, preliminary new research suggests.
But the study, which analyzed medical records from nearly 200 children aged 4 through 18, compared those who were "ever" breast-fed -- regardless of duration -- with those who had consumed only formula. The results conflict with conventional wisdom indicating that breast-feeding might protect children from a host of infections and other ailments, including allergies.
"We think breast-feeding prevents a lot of allergies, but surprisingly, we found that kids [in both groups] had similar numbers of allergies," said study author Dr. Quindelyn Cook, a resident physician in pediatrics at the University of Chicago Medical Center.
"Mothers should definitely continue to breast-feed," Cook added. "Definitely this would need to be studied on a larger scale."
Cook's study is to be presented Thursday at the American College of Allergy, Asthma and Immunology annual meeting, in San Antonio, Texas. Research presented at scientific conferences typically hasn't been peer-reviewed or published, and results are considered preliminary.
Food, skin and respiratory allergies are among the most common medical conditions affecting children in the United States, according to the U.S. Centers for Disease Control and Prevention. Occurring when the immune system reacts to environmental substances normally considered harmless, skin and food allergies among children increased substantially between 1997 and 2011, according to the CDC.
Cook and her colleagues reviewed medical charts for 194 patients at a pediatric allergy and immunology clinic over four years who were diagnosed with hay fever allergies confirmed by a skin prick test. The children were split into two groups, including 134 who had ever been breast-fed and 60 who had exclusively consumed formula.
Both groups had similar numbers of kids with hay fever, asthma, the skin condition eczema and food allergies.
But one pediatrician said comparing children who had "ever" been breast-fed with formula-fed children was not valuable when analyzing the link between allergies and infant feeding.
"Many moms breast-feed in the [hospital] nursery and at home for awhile and then switch out to formula, so there's no way you can make any conclusions from this study at all," said Dr. Charles Shubin, director of pediatrics at Mercy Family Care in Baltimore. "This study doesn't help clarify matters because it was so poorly done. There's a big difference between ever breast-fed versus exclusively breast-fed."
The American Academy of Pediatrics recommends babies be breast-fed for at least the first 12 months, and fed only breast milk for the first six months of life.
At his inner-city pediatrics practice, Shubin said, "there's very little exclusive breast-feeding" among new mothers. And, he doesn't have enough information to know whether exclusive breast-feeding would significantly alter a child's risk of developing allergies.
"Our dilemma is that we still haven't convinced people that exclusive breast-feeding is the way to go. The percentages are not where they need to be," he said. "I encourage mothers to breast-feed as much as they're comfortable doing."
The U.S. Office on Women's Health talks about breast-feeding benefits.
SOURCES: Quindelyn Cook, M.D., medical resident, pediatrics, University of Chicago Medical Center, Chicago; Charles Shubin, M.D., director, pediatrics, Mercy Family Care, Baltimore; Nov. 5, 2015, presentation, American College of Allergy, Asthma and Immunology annual meeting, San Antonio, Texas