Nursing exclusively has no effect on later weight, but many other benefits exist
TUESDAY, March 12, 2013 (HealthDay News) -- Breast-feeding has many benefits, but preventing overweight and obesity later in a child's life probably isn't among them, according to a new study.
The study included nearly 14,000 children from Belarus whose mothers were involved in a study to promote exclusive breast-feeding for longer periods. When the researchers checked on the children around age 11, they found that breast-feeding duration and exclusivity didn't make a difference in child's later weight.
Still, the study authors pointed out that breast-feeding has many advantages, and mothers should still be encouraged to breast-feed their infants.
"Although breast-feeding is unlikely to stem the current obesity epidemic, its other advantages are amply sufficient to justify continued public health efforts to promote, protect and support it," said the study's lead author, Richard Martin, a professor of clinical epidemiology at the University of Bristol in England.
Results of the study appear in the March 13 issue of the Journal of the American Medical Association.
The children in the study were initially recruited with their mothers for a study designed to assess a breast-feeding intervention program. The breast-feeding program was based on the World Health Organization/Unicef Baby-Friendly Hospital Initiative, which promotes exclusive breast-feeding and breast-feeding for longer periods of time.
Some of the practices included in the breast-feeding program included having a written breast-feeding policy, showing mothers how to initiate and maintain breast-feeding, having babies in the same room as their mothers 24 hours a day, and giving no pacifiers to the infants, Martin said.
The study included 31 hospitals in Belarus, a country in eastern Europe. Infants and their mothers were randomly selected to be in the breast-feeding-promotion group or in a group given the hospital's usual care.
The intervention substantially increased the duration of exclusive breast-feeding, according to the study. At 3 months, 43 percent of women in the intervention group were exclusively breast-feeding their babies, compared to 6 percent of those in the usual-care group. At 6 months, about 8 percent of women from the breast-feeding-program group were still breast-feeding exclusively, versus less than 1 percent of the usual-care group.
Although some previous studies suggested that breast-feeding exclusively for longer periods might curb childhood obesity, the researchers found no significant differences in body mass or in the risk of overweight or obesity when they followed up with the children about 12 years later, according to the study.
Dr. Deborah Campbell, director of the division of neonatology at Montefiore Medical Center in New York City, said she doesn't think this study is the final word on whether breast-feeding might affect later weight.
Campbell noted that, unlike a U.S. population, which would be more diverse, most of the people in Belarus have the same ethnic and racial background. They also have universal health care, and a population with higher education levels than the United States. These differences make it difficult to translate these findings to a U.S. population, she said.
Of more concern, Campbell said, was the amount of overlap between the two groups. "Even women who weren't in the intervention group breast-fed, and in the breast-feeding-intervention group, not everyone breast-fed, so there was a lot of overlap," she said.
However, "breast-feeding alone isn't a cure-all," she said. When exploring breast-feeding's relationship with obesity, "you also need to think about the ongoing diet of the child, and how physically active the child is," she said. "There are so many factors in the environment that can change outcomes."
The many known benefits of breast-feeding include a reduced risk of gastrointestinal and respiratory infections. This benefit is especially important in premature infants, Campbell said. Breast-feeding also is associated with a higher IQ and lower incidence of eczema.
And there are benefits for mom too. "Breast-feeding reduces the risk of breast and ovarian cancer," Campbell said. It also helps mothers return to their pre-pregnancy weight faster, and offers a considerable cost savings compared to buying formula.
For tips on keeping your child at a healthy weight, see the U.S. Centers for Disease Control and Prevention (http://www.cdc.gov/healthyweight/children/index.html ).
SOURCES: Richard Martin, Ph.D., professor of clinical epidemiology, University of Bristol, United Kingdom; Deborah Campbell, M.D., director, division of neonatology, Montefiore Medical Center, New York City; March 13, 2013, Journal of the American Medical Association