I think I can safely assume that when it comes to feeding newborns, people have heard that if possible breastfeeding is best - immune system, bonding, etc etc. But when do you wean? Ten years ago, the World Health Organization recommended that mothers "exclusively breastfeed for the first six months of their infants' lives," and this recommendation was picked up by governments around the world.

Now, a study in the British Medical Journal says perhaps that can be adjusted down to four months, based on information including more recent research. Naturally, there are caveats and controversies.

Pros and Cons

The paper makes the distinction between developed and developing countries - "
exclusive breastfeeding for six months is readily defendable in resource poor countries with high morbidity and mortality from infections," the authors say. And even in the West, infants "who were exclusively breastfed for six months were less likely to succumb to infections, such as pneumonia, than those fed for less than six months." However, the authors also said newer research shows babies "exclusively breastfed for six months are at a higher risk of developing
anaemia, which has been linked to adverse mental, motor and psychosocial problems. The study also found evidence of a higher incidence of food allergies and a higher risk of developing coeliac disease.

The authors also "In the West, any proposed beneficial effects of exclusive breast feeding to six months on infection risk would need to be weighed against plausible, or at least suggestive, evidence for adverse effects," the authors reported.suggest that waiting six months to introduce solid foods can lead to the underdevelopment of taste, which might have long-term implications on diet - the enjoyment of bitter foods like leafy green veggies may take longer, which could lead to all sorts of dietary issues like diabetes and obesity. (This one sounds like a bit of a stretch to me, but maybe there is something to it. How many of us liked spinach or asparagus or broccoli as kids but love it now?)

Who did you say you work for?

And as any good reporter should do, the folks at Nature noted that of the four authors (
child-health and nutrition scientists at University College London and the universities of Edinburgh and Birmingham, UK), three "have performed consultancy work or received funding from companies manufacturing infant formula and baby food in the past three years." Does that invalidate their findings? No. And according to one of the researchers, Mary Fewtrell, the review itself wasn't funded by those companies: "My colleagues and I are independent paediatricians and scientists, funded by universities or hospitals, and we received no funding for doing this review other than our normal salaries. All of us have had links with industry at some point. We are making no comment in our paper about what type of solid foods should be introduced – this could be home-prepared or commercial depending on the mum's choice – the main issue is that the food should be nutritionally adequate and safe." Does it make me a little wary of the recommendations? Sure, as would any drug study where the authors have ties to pharma. But, many scientists have links to industry. Anyway, I appreciated that they were calling for more evidenced-based studies, not smaller observational ones from which data support the six month mark.

Fewtrell also noted that they weren't stating in black or white what moms (or mums, if you live near Dr. Rugbyologist) should do. "We are not ourselves giving 'new advice' as has been stated in some papers – that is not our job. However, our own opinion is that currently the balance of data would favour introducing solids alongside continued breastfeeding between 4 and 6 months – when the mother feels her baby is ready."

Anyone else want to weigh in?

The Cochrane Collaboration's most recent study backs the WHO, but recommendations from a
European Food Safety Authority committee falls more on the side of the new paper. The EFSA panel stated in 2009 that it "concludes that the introduction of complementary food into the diet of healthy term infants in the EU between the age of 4 and 6 months is safe and does not pose a risk for adverse health effects (both in the short-term, including infections and retarded or excessive weight gain, and possible long-term effects such as allergy and obesity)."

Perhaps coincidentally, the U.S. Surgeon General is holding a meeting on January 20 called "The Surgeon General’s Call to Action to Support Breastfeeding," which will outline "evidence-based steps that all sectors of a community can take to remove obstacles faced by women who want to breastfeed their babies. While 75 percent of U.S. mothers breastfeed at the start, only 13 percent of babies are exclusively breastfed at six months."

I think it's important to note that they aren't saying, "Hey, moms, go out and buy formula." They aren't even advocating you switch breast milk with formula. They're saying that in some cases it may be ok to introduce solid foods between four and six months, versus the "gold standard" of six months. The Pediatric Group of the British Dietetic Association said the same thing in a position statement, stressing that infants need to be considered individually.