From NY Times, Link: http://t.co/rBXCORx3mM
Many women who are unable to breast-feed feel guilty about it and worry they may be depriving their children of a range of benefits. Groups like the American Academy of Pediatrics and the World Health Organization recommend six months of exclusive breast-feeding for all infants, citing studies that show breast milk is easily digestible and has nutrients that are superior to or absent from infant formulas, including immunological substances that reduce rates of infection and fatty acids important in brain development.
But now a new study suggests that many of the long-term benefits attributed to breast-feeding may be an effect not of breast-feeding or breast milk itself but of the general good health and prosperity of women who choose to breast-feed.
Researchers at Ohio State University compared 1,773 sibling pairs, one of whom had been breast-fed and one bottle-fed, on 11 measures of health and intellectual competency. The children ranged in age from 4 to 14 years.
The researchers recorded various health and behavioral outcomes in the sibling pairs, including body mass index, obesity, asthma, hyperactivity, reading comprehension, math ability and memory-based intelligence. The study, published online in Social Science & Medicine, found no statistically significant differences between the breast-fed and bottle-fed siblings on any of these measures.
By studying “discordant” siblings — one of whom had been breast-fed and the other not — the authors sought to minimize the possibility that racial, socioeconomic, educational or other differences between families could affect the results. Many earlier studies on breast-feeding failed to control for such factors, they say.
… researchers have consistently found large socioeconomic and racial disparities in breast-feeding rates. A C.D.C. survey in 2008 found that 75 percent of white infants and 59 percent of black infants were ever breast-fed, and in 2013, the agency reported that 47 percent of white babies but only 30 percent of black babies were still being breast-fed at 6 months. Compared with bottle-fed infants, breast-fed babies are more likely to be born into families with higher incomes, have parents with higher educational attainments, and live in safer neighborhoods with easier access to health care services.
Still, sibling studies such as this latest one do not solve all the problems of bias…
Geoff Der, a statistician at the University of Glasgow who has worked with the same data in previous studies, said that the findings in the present study were robust and the authors’ method for eliminating selection bias was powerful…“In a society with a clean water supply and modern formulas,” he said, “a woman who isn’t able to breast-feed shouldn’t be feeling guilty, and the likelihood that there’s any harm to the baby is pretty slim.”
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