The latest hype in medical research, caused by a paper released stating that the benefits of breast feeding has been overstated. Every nut job and conspiracy theorist jumped up and shouted: “I told you so!!!!!!” Meanwhile no one reads the thousands of pier reviewed scientific papers released on the subject over many decades. This reminds me of the anti-vaccers.
Breast feeding isn’t for everyone and not possible for everyone. The facts are very hard to ignore about the benefits that breastfeeding provides.
I am posting that article below, as well as a very good follow-up article by a pediatrician, that explains why he does not agree with that study and why it is important to look at the facts.
A new study confirms what people like our own Hanna Rosin and Texas A&Mprofessor Joan B. Wolf have been saying for years now: The benefits of breast-feeding have been overstated. The study, published in the journal Social Science & Medicine, is unique in the literature about breast-feeding because it looks at siblings who were fed differently during infancy. That means the study controls for a lot of things that have marred previous breast-feeding studies. As the study’s lead author, Ohio State University assistant professor Cynthia Colen, said in a press release, “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.”
Colen’s study is also unique because she looked at children ages 4-14. Often breast-feeding studies only look at the effects on children in their first years of life. She looked at more than 8,000 children total, about 25 percent of whom were in “discordant sibling pairs,” which means one was bottle-fed and the other was breast-fed. The study then measured those siblings for 11 outcomes, including BMI, obesity, asthma, different measures of intelligence, hyperactivity, and parental attachment.
When children from different families were compared, the kids who were breast-fed did better on those 11 measures than kids who were not breast-fed. But, as Colen points out, mothers who breast-feed their kids are disproportionately advantaged—they tend to be wealthier and better educated. When children fed differently within the same family were compared—those discordant sibling pairs—there was no statistically significant difference in any of the measures, except for asthma. Children who were breast-fed were at a higher risk for asthma than children who drank formula.
Colen’s conclusion is the same one I came to when I wrote about a British pilotprogram that would pay women to breast-feed: Breast-feeding is good, but it shouldn’t be such a huge societal priority. As Colen put it, “We need to take a much more careful look at what happens past that first year of life and understand that breast-feeding might be very difficult, even untenable, for certain groups of women. Rather than placing the blame at their feet, let’s be more realistic about what breast-feeding does and doesn’t do.”
As more and more research comes out showing that the benefits of breast-feedingare modest at best, I’m starting to come around to the French feminist theorist Elisabeth Badinter’s views, which I once thought were overly radical and sort of bananas. I’m all for women breast-feeding if that is what is right for their families, but as Badinter does, I am finding the cultural push for all women to breast-feed, no matter how difficult it is, to be more and more oppressive. Hopefully this study will give women who can’t or don’t want to breast-feed for whatever reason more ammunition to tell the breast-is-best purists to piss off.
Here is the follow-up article:
An interesting and provocative study, published last month in the journal Social Science and Medicine, suggests that the benefits of breastfeeding are overstated. In a clever experimental design, the authors analyzed data from a national database managed by the United States Department of labor’s Bureau of Labor Statistics. They queried from this database whether breastfeeding impacts any of the following outcomes in families with young siblings: body mass index, obesity, asthma, hyperactivity, parental attachment, behavioral compliance, reading comprehension, vocabulary recognition, math ability, memory based intelligence, and scholastic competence. They firstly looked at all families with siblings and noted that siblings who were breast fed fared better than their non-breastfed counterparts on all of the outcome variables measured except one; asthma rates were surprisingly higher among the breastfed siblings compared to the formula-fed siblings. When the authors looked specifically at families in which one sibling was breastfed but the other sibling was formula fed (this sub-analysis helps control for environmental variables other than breastfeeding that may explain the differences) they found that there were no differences between siblings in any of the outcomes measured. The authors conclude, therefore, that the benefits of breastfeeding are overstated.
The media and blogosphere followed suit with sensationalized headlines:
Did this paper really demonstrate that breastfeeding isn’t as beneficial as we once thought? Well, I have a few comments to make in that regard:
Firstly, the ‘surprising’ asthma outcome is not really suprising. In recent decades, there has been a belief that breastfeeding is protective from asthma. Since asthma runs strongly in families, it is very possible that mothers who have strong histories or family histories of asthma are compelled to do whatever they can to prevent asthma in their children. Since it has been widely thought that breastfeeding is protective against asthma, it is plausible that mothers in this study with asthma and/or family histories of asthma were more likely to choose breastfeeding in an attempt prevent their children from developing asthma. Since these children were genetically more likely to develop asthma, many of them likely did develop asthma despite having been breastfeed. In this case, it was not the breastfeeding that increased the likelihood of developing asthma, it was the likelihood of developing asthma that increased the probability of the mother choosing to breastfeed her child. Though the analysis picked up on the connection, the design is only able to identify the correlation, not the direction of the cause nor if there is a causal relationship at all.
Secondly, the authors only looked at the impact of breastfeeding on the children; the maternal health benefits of breastfeeding such as protection from cancers, diabetes, cardiovascular disease, and mental health problems, were not considered at all.
Finally, I am suspicious of the outcome measures that were chosen by the authors. As one can see from the table below, there is no shortage of scientific literature demonstrating both the benefits of breastfeeding and the risks of formula feeding:
If, from the list above, I selected the conditions for which there is the weakest connection between breastfeeding and protection from said conditions, I would choose asthma, obesity and neurocognitive development. In other words, current research has not been able to demonstrate very strongly that breastfeeding reduces the incidence of asthma, improves brain development, or protects from obesity. If those were the only reasons to promote breastfeeding, there wouldn’t be a very strong public health case to make for breastfeeding promotion. However, there are far more compelling reasons, as illustrated above, than those three outcome measures. Amazingly, the authors only chose those three specific outcomes (obesity, asthma, and a variety of neurocognitive outcomes) to measure in their study. It is almost as if the authors were rooting for a negative outcome at the onset of the study by picking outcome measures that were least likely to show any difference.
So, has this study demonstrated that formula feeding is the same as breastfeeding? I really don’t think so. And has this study demonstrated that the benefits of breastfeeding are overstated? For obesity, asthma, and cognitive outcomes: very possibly. But for the many other benefits that breastfeeding confers to both the child and the mother: not at all.
Dr. Flanders is a Toronto pediatrician practicing primary care and consultation pediatrics at Kindercare Pediatrics. He also works at the North York General Hospital’s Pediatric Eating Disorders Program and the Infant, Child, and Adolescent Nutrition Clinic.