By Melissa Bartick, MD, MSc and Briana Jegier, PhD
If you want to grab news headlines, all you have to do is say "breastfeeding has no effect on child well-being." It's like shouting "fire" in a crowded movie theater. You create a Jerry Springer spectacle of moms fighting other mothers about who is doing best for their children. But that's not the truth about who women are, or what science has to say to say about breastfeeding.
This week, a widely reported sibling study by Colen and Ramey concluded that breastfeeding has "no effect" on "child well-being." But, what's the truth here? To start with, there have been thousands of studies on breastfeeding and health outcomes, and the best and most effectively designed studies available today demonstrate that breastfeeding changes health risks for mothers and children. Strong evidence exists for a relationship between breastfeeding and SIDS, necrotizing enterocolitis (a deadly disease of premature infants), hospitalization for lower respiratory tract infections, ear infections, diarrhea, Crohn's disease,ulcerative colitis, and acute leukemia. Several of these diseases have significant mortality rates and huge economic costs for families, the healthcare system, and society at large. But this study looked at only two physical diseases, asthma and obesity. Thus, for the authors to conclude that breastfeeding has "no effect on child well-being" is a gross overstatement and is overtly false.
There are some great summaries on the state of breastfeeding research from reputable organizations available online including the WHO, the AAP, and the AHRQ, that provide information on the extent to which breastfeeding changes risks for mothers and children. These are risks across the population, but they do not guarantee a particular outcome for any individual baby or mother. Some of those risk changes are small and some are quite large which is why it is so important to educate parents-to-be so that they truly can make an informed decision.
This new study looked at over 1700 siblings where one child was breastfed and the other was not, and followed them over time. In addition to asthma and obesity, this study looked at intelligence, behavioral compliance, and parental attachment. However, the study was problematic from inception because the definition of "breastfed" used was problematic -- a breastfed child in the study may have breastfed for as little as one day, or may have breastfed for as long as several years. For purposes of the study, both were treated the same. We know, however, for most conditions, the duration and intensity of breastfeeding is very important to health outcomes.
Although the authors concluded that breastfeeding had no effect, their results actually showed the opposite. From a statistics point of view, all children in the study who were ever breastfed did statistically better than all children who were not, with the exception of asthma. When they looked within siblings where one was ever breastfed and one was not, children who were ever breastfed still did better, including asthma, but the differences were not statistically significant (in other words the better differences between siblings could simply be chance).
Even the conclusion on the intelligence in this study is opposite the most powerful study to date on breastfeeding and IQ, the PROBIT study. This study was the gold-standard in study design, a randomized controlled trial in Belarus between hospitals and clinics that implemented supportive breastfeeding policies and those that did not, therefore eliminating the issues of other environmental factors. Infants in the intervention group had significant increases in intelligence compared to the control group, despite the fact that less than half of the intervention infants were exclusively breastfed for three months.
Another problematic area in this study is that it assumes that siblings would have the same experience and environment, which is a pretty large leap. Context and environment might change the mother's perception of her ability to breastfeed. Thus, the premise any differences between siblings may not be due to breastfeeding, but may be due to the same factors that influenced the mother's feeding choice. Further, the authors assume that a healthier child might be the child who is selected by the mother to breastfeed. However from practice, the opposite is actually more likely because so much education and effort is aimed at supporting mothers who have less healthy children to breastfeed, especially mothers of preterm and low birth weight children.
Despite this study's absurd conclusion that breastfeeding does not impact child well-being, it does raise some important questions about what the focus of the breastfeeding conversation should be, namely breastfeeding disparities. We should really be focusing on the fact that some mothers perceive that they cannot breastfeed for preventable reasons like lack of evidence-based education about breastfeeding, unfriendly family policies in workplaces and schools, and unpaid family leave. These problems are ones that have solutions, though not all of them easy, that would allow each family to make the informed decision on how to feed their baby based on the health impact rather than these preventable and discriminatory barriers.
We need to shift the conversation from whether breastfeeding is good or not, to ways to level the playing field for all Americans with policies like offering paid sick leave and paid maternity leave through insurance (the FAMILY Act now in Congress), and support for working mothers so that they can continue to breastfeed (like through the Support for Working Mothers Act, or SWMA, now in Congress). These kinds of bills will make us a stronger, healthier, and more productive nation, and reduce the growing gap between rich and poor that is eroding our civilized society.