MONDAY, June 13 (HealthDay News) -- Breast-feeding appears to reduce the risk of SIDS by up to 73 percent, especially when babies are exclusively breast-fed, a new study suggests.
Breast milk is widely considered the best food for infants, and studies have shown breast-feeding aids babies' development and reduces the risk of disease for both infants and their mothers. Now, there is more evidence that breast-feeding may reduce the risk of Sudden Infant Death Syndrome (SIDS), which claims the lives of about 2,300 infants a year in the United States, according to federal statistics.
"Breast-feeding has many benefits for mothers' and infants' health," said lead researcher Dr. Fern R. Hauck, an associate professor of family medicine and public health at the University of Virginia in Charlottesville. "This study shows another important reason that mothers should breast-feed their infants, and ideally, this should be exclusive."
Previous research of this issue has been inconclusive, but these findings provide strong evidence of the protective association, Hauck said.
The report was published in the June 13 online edition of Pediatrics.
For the study, Hauck and colleagues looked at the connection between breast-feeding and SIDS by doing a meta-analysis of 18 studies. In this process, researchers look for common threads by combining the results of individual studies.
Their analysis showed that for infants who received any amount of breast milk for any time period, there was a 60 percent reduction in the risk of SIDS. When the researchers took into account other factors such as socioeconomic status, smoking and infant sleep position, the reduction in the risk of SIDS dropped to 45 percent, Hauck said.
However, when the researchers looked at the reduced risk of SIDS among infants who were exclusively breast-fed, the risk was reduced by 73 percent.
"These results indicate that breast-feeding is strongly protective against SIDS. Exclusive breast-feeding confers the most protection," Hauck said.
Although the reasons for the association between breast-feeding and the reduced risk of SIDS is unclear, there are several theories.
"Breast-fed infants more arousable during sleep," Hauck said. This may be due to the infants' need to be nursed, which may interrupt sleep. (SIDS appears to be linked to a defect in arousability from sleep, according to some experts.)
In addition, breast-fed infants have fewer bouts of diarrhea and upper and lower respiratory infections, which are associated with vulnerability to SIDS, she said.
Moreover, there are benefits of breast milk to immune system at a time when infant's own immunity is still developing and the immunity the infant received from the mother is waning, which may also play a role in reducing the risk of SIDS, Hauck explained.
Based on these findings, "the recommendation to breast-feed infants should be included with other SIDS risk-reduction messages, to both reduce the risk of SIDS and promote breast-feeding for its many other infant and maternal health benefits," the investigators concluded.
Dr. Lourdes Q. Forster, an assistant professor of pediatrics at the University of Miami Miller School of Medicine, said that "we had been thinking that breast-feeding had a protective effect, but this solidifies the evidence."
The advice from the American Academy of Pediatrics is clear, Forster said. "Mothers should exclusively breast-feed their babies in the first six months of life and continue to nurse through the first year of life with the addition of supplemental foods," she said.
In addition to all the other benefits of breast-feeding, the reduction in the risk of SIDS is another important one, Forster said.
For more on SIDS, visit the U.S. National Library of Medicine.
SOURCES: Fern R. Hauck, M.D., M.S., associate professor, family medicine and public health, University of Virginia, Charlottesville; Lourdes Q. Forster, M.D., assistant professor, pediatrics, University of Miami Miller School of Medicine; June 13, 2011, Pediatrics, online
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