Breast-feeding Benefits Appear to be Overstated, According to Study of Siblings
A new study comparing siblings who were fed differently during infancy suggests that breast-feeding might be no more beneficial than bottle-feeding for 10 of 11 long-term health and well-being outcomes in children age 4 to 14.
The outlier was asthma, which was associated more with breast-feeding than with bottle-feeding.
The study also included an analysis of outcomes across families of different races and socioeconomic circumstances for comparison purposes, and those results matched other studies suggesting that breast-feeding’s benefits to children outweigh bottle-feeding.
The lead researcher noted that there is a clear reason for that.
“Many previous studies suffer from selection bias. They either do not or cannot statistically control for factors such as race, age, family income, mother’s employment - things we know that can affect both breast-feeding and health outcomes,” said Cynthia Colen, assistant professor of sociology at The Ohio State University and lead author of the study.
“Moms with more resources, with higher levels of education and higher levels of income, and more flexibility in their daily schedules are more likely to breast-feed their children and do so for longer periods of time.”
Breast milk is a unique nutritional source that cannot adequately be replaced by any other food, including infant formula. Although pollutants can accumulate in breast milk, it remains superior to infant formula from the perspective of the overall health of both mother and child.
Infants are fragile and susceptible to disease, partly because their bodies are not fully developed. They must be treated with special care and given adequate nourishment. Infant formulas are able to mimic a few of the nutritional components of breast milk, but formula cannot hope to duplicate the vast and constantly changing array of essential nutrients in human milk. Nevertheless, breastfeeding is often devalued, both in the United States and abroad, and in many parts of the world it must compete with relentless advertising by infant-formula companies.
Studies have demonstrated a number of important health benefits to breastfeeding. Among them:
- Breast-fed children are more resistant to disease and infection early in life than formula-fed children
- Breast-fed children are less likely to contract a number of diseases later in life, including juvenile diabetes, multiple sclerosis, heart disease, and cancer before the age of 15
- Mothers who breastfeed are less likely to develop osteoporosis later in life, are able to lose weight gained during pregnancy more easily and have a lower risk of breast, uterine and ovarian cancer
Breastfeeding also has economic advantages: it’s cheaper than buying formula and helps avoid medical bills later because it helps equip the baby to fight off disease and infection. New parents are well advised to learn all they can about the pros and cons of breast milk and formula. See below for more information on the benefits of breastfeeding.
Previous research has identified clear patterns of racial and socioeconomic disparities between women who breast-feed and those who don’t, complicating an already demanding choice for women who work outside the home at jobs with little flexibility and limited maternity leave.
Colen’s study is also rare for its look at health and education benefits of infant feeding practices for children age 4 to 14 years, beyond the more typical investigation of breast-feeding’s effects on infants and toddlers.
Federal health officials have declared breast-feeding for at least six months a national priority, which could end up stigmatizing women who can’t opt to nurse their babies, Colen said.
“I’m not saying breast-feeding is not beneficial, especially for boosting nutrition and immunity in newborns,” Colen said. “But if we really want to improve maternal and child health in this country, let’s also focus on things that can really do that in the long term - like subsidized day care, better maternity leave policies and more employment opportunities for low-income mothers that pay a living wage, for example.”
The study is published in the journal Social Science & Medicine.
Demographic differences across families that can bias studies in favor of breast-feeding include parental race, age, marital status, family income, insurance coverage, the mother’s education and employment, and whether a woman smokes or drinks during pregnancy.
“When we get more advantaged moms selecting into breast-feeding and we know those traits also will affect the health outcomes, it’s not clear what’s affecting an outcome like obesity - is it breast-feeding itself or those other background characteristics?” Colen said.
Colen used data from the 1979 cohort of the National Longitudinal Survey of Youth (NLSY), a nationally representative sample of young men and women who were between ages 14 and 22 in 1979, as well as results from NLSY surveys between 1986 and 2010 of children born to women in the 1979 cohort. The children were between ages 4 and 14 during the time period studied.