Most of the evidence for the purported benefits of breastfeeding for term infants is weak, conflicting and riddled with confounders … not to mention distorted by white hat bias. Time and again, rigorous studies have failed to confirm the breathless pronouncements of lactivists. Now a new study shows that far from preventing childhood obesity, breastfeeding seems to increase it.
[pullquote align=”right” cite=”” link=”” color=”” class=”” size=””]Yet another claim of lactivists is demonstrated to be false.[/pullquote]
The title of the study published JAMA Pediatrics is a mouthful: Effects of Promoting Long-term, Exclusive Breastfeeding on Adolescent Adiposity, Blood Pressure, and Growth Trajectories A Secondary Analysis of a Randomized Clinical Trial.
This analysis found:
A randomized intervention that increased the duration and exclusivity of breastfeeding was not associated with lowered adolescent obesity risk or BP. On the contrary, the prevalence of overweight/obesity was higher in the intervention arm…
It is a secondary analysis of data derived from the PROBIT studies, long considered some of the gold standard studies in breastfeeding research.
The Promotion of Breastfeeding Intervention Trial (PROBIT) was designed to overcome limitations inherent in observational studies of the long-term effects of breastfeeding on child outcomes including adiposity and blood pressure. We cluster-randomized 17 046 children from 31 clinics, born between 1996 and 1997, to either a control arm or breastfeeding promotion intervention (based on the World Health Organization and United Nations Children’s Fund Baby-Friendly Hospital Initiative).
The initial data from the studies found that the only solid evidence of benefit from breastfeeding was limited to a slightly reduced incidence colds, and a slightly reduced incidence of episodes of diarrheal illness across the entire population of term infants in the first year. But lead researcher Dr. Michael Kramer believed that the data suggested that breastfeeding might have a beneficial effect on IQ and obesity.
Subsequent data from his studies and others has caused him to change his mind about breastfeeding and obesity. The data is consistent with Kramer’s previous observations:
We previously reported no evidence of a protective effect of the breastfeeding intervention on adiposity or BP at 6.5 and 11.5 years.
So one of the original proponents of the claim that breastfeeding prevents obesity found out years ago that it does not and is now emphatic in denying a connection:
An intervention that achieved substantially greater duration and exclusivity of breastfeeding in Belarus did not prevent over-weight or obesity or lower BP levels at age 16 years, despite differences in growth rates between the trial arms at various ages. On the contrary, overweight and obesity were more prevalent in the breastfeeding promotion intervention arm. While there are many reasons for promoting breastfeeding duration and exclusivity, our trial does not indicate that breastfeeding prevents obesity or lowers BP in childhood or adolescence.
Dr. Kramer does nevertheless engage in a bit of white hat bias. Had his data shown a decrease in risk of obesity in the group that was breastfed longer he almost certainly would have claimed that breastfeeding prevents obesity. But in keeping with the white hat bias of all breastfeeding researchers (that breastfeeding must be better than not breastfeeding) he does not follow where the data leads him: the possibility that breastfeeding causes obesity. I point this out not because I believe that the evidence shows that breastfeeding causes obesity (although it might), but because it highlights the profound bias in favor of breastfeeding within the scientific community.
Kramer himself has long been far more sober about the purported benefits of breastfeeding than many other lactivists.
In a 2016 interview on Canadian radio, Kramer was emphatic that breastfeeding does NOT prevent obesity, does NOT prevent allergies, and does NOT prevent asthma. When asked why lactivist organizations continue to insist on benefits that have been shown not to exist, he explained that these organizations rely upon preliminary data and simply refuse to accept anything that contradicts it. He was quite blunt that about the fact that lactivist organizations won’t accept scientific evidence that doesn’t comport with what they believe and he worries that their insistence of exaggerating benefits will undermine women’s trust in healthcare providers.
In the interview Kramer was refreshingly honest in acknowledging that public health officials underestimate the difficulties of breastfeeding. When asked whether the public health community can present the actual scientific evidence instead of the selected evidence that it prefers to present, he ruefully explained that “no one likes shades of gray,” preferring black and white pronouncements instead.
Breastmilk is food not magic.
Sadly breastmilk has been turned from food into manipulation. Lactivists and their organizations, especially the Baby Friendly Hospital Initiative, have made the harassment, inconveniencing and embarrassment of women a cornerstone of their efforts to promote breastfeeding. As Kramer himself acknowledges, most of their claims are empirically false and their efforts are beginning to backfire.
Michael Kramer, the person whose research led to the claim that breastfeeding reduces the risk of obesity, has officially withdrawn that claim. Does anyone want to bet against me when I predict that lactivist organizations will ignore the latest evidence and refuse to remove the claim from their websites and educational materials?
Lactivist organizations are certain that breast is best even when the evidence not only doesn’t support their claims but actually contradicts them. Regrettably, they are so sure of their own righteousness that they have become entirely unmoored from scientific evidence. Mothers and babies are placed at serious risk, under significant pressure, and with deadly consequences as a result.
