Breast-feeding for 6 months provides a greater reduction in a baby's risk of respiratory infections than feeding for fewer months, according to a study presented at the Pediatric Academic Societies meeting.
The risk of pneumonia was fourfold less, and recurrent ear infections (otitis media) twofold less in the babies who had breast-fed for 6 months when compared to 4 months, said lead author Caroline Chantry, a professor of pediatrics at the University of California at Davis. There was no difference in risk of colds, wheezing or an ear infection in the first year, however.
Even so, the data show that with each increasing "dose" of breast milk, babies are further protected from serious respiratory infections, Chantry said. "The bottom line is that breast-feeding for 6 months or longer gave us the lowest adjusted illness rates for all illnesses at all time points," she said.
The American Academy of Pediatrics (AAP) recommends breast-feeding exclusively for 6 months, and continuing it as a supplement for a year, and the World Health Organization (WHO) recommends 4 months of exclusive breast-feeding followed by 2 years of supplemental feeding. But until this study, there was no data showing that the 6-month period was better than 4 months in curbing respiratory infections, Chantry noted.
She and colleagues at UC Davis and the University of Rochester decided to compare the two time periods. Because there are so few women in the US who exclusively breast-feed, the researchers also included women who supplement with formula, but don't use it every day.
They analyzed federal data on infections in 2,277 children aged 6 to 24 months, and divided them into five groups: those who had been formula-fed only; fully breast-fed for less than 1 month; for 1 to 4 months; from 4 to less than 6 months; and for 6 months or more.
Despite the continuing stream of data showing the benefits of breast-feeding, especially for longer periods of time, Chantry said that it's still "a minority of women" who achieve the WHO or AAP recommendations.
There are many reasons why women are having trouble meeting those goals, including a lack of support from hospitals and physicians, and barriers in the workplace, she said. Some states, including California, have tried to get employers to be more accommodating, she added.