In the past, research has linked breastfeeding with
prevention of Sudden Infant Death Syndrome (SIDS), but a new German study
published in the journal Pediatrics has found that infants who are
formula-fed are twice as likely to die of SIDS than breastfed infants.
The German Study of Sudden Infant Death examined the cases
of 333 infants who died of sudden infant death syndrome along with 998
age-matched controls, between 1998 and 2001.
A total of 49.6 percent of cases and 82.9 percent of
controls were breastfed at two weeks of age. Exclusive breastfeeding at one
month of age halved the risk of SIDS; partial breastfeeding at the age of
one month also reduced the risk, but after adjustment this risk was not
significant. Being exclusively breastfed in the last month of life or before
the interview reduced the risk, as did being partially breastfed.
SIDS is the leading cause of death for infants in developed
countries, and yet the causes are not fully understood. While previous research
has documented the relationship between breastfeeding and low SIDS rates, there
was speculation that the relationship may have more to do with socioeconomic
status, smoking or other lifestyle issues. So in this study, researchers
adjusted the data to control for the effect of socioeconomic status.
They also suggested a mechanism that could explain a causal
relationship between breastfeeding and SIDS-prevention. Most infants who die
of SIDS are between two and four months old. At this age, maternal acquired
immunoglobulin G is low and the infant has not yet begun to produce large
amounts of its own immunoglobulin. Breastmilk contains immunoglobulin and
cytokines, which may help stave off infections which are believed to
contribute to SIDS. It has also been shown that breastfed infants are more
easily aroused than formula-fed babies, another mechanism which could help
prevent SIDS.
After the age of four months, infants are at a lower risk
for SIDS and the older they get, the more their risk declines. Because the
risk is so low by six months of age, researchers recommend that all babies
be breastfed until six months of age.
Wendy Priesnitz is the
founder and editor of this and other magazines. She
is the author of 13 books.