Here's the link to the full paper. http://www.bmj.com/content/342/bmj.c5955.full This is important, because as I've mentioned before, news reports of the paper itself are often really misleading.
I think this is a bad paper to analyze, since it's not a study. But it's getting some hype and I think it's worth seeing what it's saying. First off, it's way too easy to say that these authors are in the pocket of the food companies and dismiss everything that they are saying. We can't really do that though, since the media coverage demands a more substantial response.
Papers answer a question. This one asks if it's time for a reappraisal of the recommendations of exclusive breastfeeding for 6 months because of new expert opinion and new data to be considered since the WHO recommendations and the Cochrane Review of 2002. Is it time to change the recommendations for breastfeeding?
The lead author has asked this question before, in 2007 in the American Journal of Clinical Nutrition, and is a researcher in complementary foods. She has an angle: she wants her researched funded. In this article, she quotes her own research. Of course, everybody has an angle. We should acknowledge our biases honestly, not just our overt conflicts of interest.
So the question is again, is it time to change the recommendation on exclusive breastfeeding. How do they answer that? They are going to review the literature. This is where most studies (if this was one) would define criteria for which studies would be included in their review. That's nowhere to be found. They will look at "evidence for promoting six months’ exclusive breast feeding" and solid food introduction in formula feeding children as well, since in "countries where early formula feeding is prevalent, the timing of introduction of solid foods in all infants...is useful to consider." No. It's not. That is an opinion and it's inconsistent with the question. We're not going to get an insight into why these particular studies made it into this paper. We call this, among other things, "cherry picking:" picking studies that are supportive to your position and ignoring or downplaying the significance of others.
Then they look at the Cochrane review from 2002: 16 studies, including 2 randomized trials (therefore good), 2 observational studies (therefore not as good). Oddly, the Cochrane review on this subject was updated in 2006, but this paper uses the 2002 review. The paper's authors acknowledge a real decrease in infections, both respiratory and GI, and potential risk for iron deficiency. Then this study is mentioned: "By contrast, Lanigan and colleagues, in a concurrent systematic review of 33 studies on the health effects of the timing of the introduction of solids in breastfed and formula fed infants, found no compelling evidence to support change from the then existing recommendation to introduce solids at four to six months." Fine, will give you that's true, but the research question is still about breastfed kids, right? A review of a bunch of studies that include data on children fed formula is inconsistent with the question we are exploring. Here again, the criteria used for a study to be included in this paper would have been nice. This study shouldn't be here.
As the authors talk about the WHO information, they cite a number of good studies that show that the duration of breastfeeding matters in terms of infection protection. However, "The large representative UK Millennium cohort study suggested 53% of admissions for gastroenteritis and 27% of those for chest infection could be prevented each month by exclusive breast feeding; but, importantly for practice, it was the introduction of infant formula, not solid foods, that predicted increased hospital admission." Now why say that? Exclusive breastfeeding means exclusive breastfeeding, so it shouldn't matter what messed up that infection risk. I see that as saying that the WHO recommendations for infection being related to the length of exclusive breastfeeding are good. No need to revisit.
When they look at nutritional adequacy, they say that the studies show that 6 months is adequate, but that there is research, ongoing, which may call that into question."Indeed, Wells and Reilly, following a systematic review of infant energy requirements, breast milk output, and energy content, calculated that many mothers who exclusively breast fed would not support their infant’s energy requirements to six months; an important matter under further investigation."
Well, then, let's wait for the peer-reviewed journal to publish the answer to that. And if we go to the original question, (is the timing right to revisit the recommendation for 6 months of exclusive breastfeeding) and they are citing research that is under investigation, then the timing isn't right.
The section on allergy and celiac disease is filled with words like "weak," "perhaps" and cite observational studies, the same type of studies they objected to in the Cochrane report. They mention two ongoing trials looking at allergic disease. If they are ongoing, then the timing is not right to revisit the recommendation for 6 months of exclusive breastfeeding.
Then in the "longer term" section they cite two contradictory sources and say that other studies are observational and randomized studies would be helpful. Again, not enough info, and therefore not time to revisit the recommendation.
They proceed to say that "Exclusive breast feeding for six months is readily defendable in resource poor countries with high morbidity and mortality from infections." Maybe England's health care system rocks and the English are loaded with expendable money, but anything that makes healthcare more affordable is worth it to me.
While acknowledging the decreased infection risk (which they continue to downplay) they have a list of complications from exclusively breastfeeding including iron deficiency (maybe), allergies (maybe) and celiac disease (maybe). You have to believe these are risks in order to buy the premise that the risk of iron deficiency, allergies and celiac disease might outweigh any benefits 6 months of exclusive breastfeeding has on infection.
It ends with a bunch of hypotheticals, suggestions for further research and a call to re-examine the evidence. I don't buy it.
Jenny Thomas, MD, IBCLC, FAAP, FABM
http://www.who.int/nutrition/topics/optimal_duration_of_exc_bfeeding_review_eng.pdf