MORE ON THE CORRECTNESS OF BREAST-FEEDING

The New York Times shocked women last week with an astonishing article in its "Science Times section" titled, "Breast-feed or Else." While laying claim to a balanced approach by describing as "controversial" a public health campaign that compares the failure to breast feed as equivalent to smoking while pregnant," the paper, nevertheless, ended up producing an extremely biased article. In claiming positive outcomes to breast feeding that are unjustified by scientific studies, the Times effectively told parents that giving their babies formula is tantamount to letting them smoke.

But the costs of nursing are substantial: the reduced time for work due to the need to pump, nurse, eat and sleep has a huge economic and social impact on women and their families. Nursing can also lead to depression or other unhealthy emotional states. It can be painful, and there are sometimes medical reasons why nursing is not recommended. Human cytomegalovirus (HCMV) infections can be transmitted by breast milk and can cause considerable problems in newborn babies - and sometimes lead to life-threatening illnesses. Drug addicts obviously should not nurse; but even smokers and drinkers ought to consider the impact (and quantity) of their use on their babies.

And for some women the milk simply isn't there despite conscientious efforts. This can lead to either health problems for the baby who isn't getting enough calories, or paying $4-$10 per ounce for donated milk (if it's available). For a five-month old baby downing about 30 ounces a day, that's one pretty little college fund gone in human milk.

For these reasons, many scientists have investigated the purported benefits of human breast milk for infants (largely ignoring the mother in their calculations), and the results are mixed. Only in a narrow segment of the population is nursing actually a bad idea, but the real question is how good is good? Can we quantify the extra benefit? Is nursing really so much better than formula that we can make a similar comparison to the risk of smoking and not smoking?

In affirming this comparison, the Times extensively quoted Dr. Lawrence Gartner, chairman of the breast-feeding section of the American Academy of Pediatrics (AAP). Gartner claimed that breast-feeding protects "against acute infectious diseases - including meningitis, upper and lower respiratory infections, pneumonia, bowel infections, diarrhea and ear infections." The Times added that the AAP claims "Some studies also suggest that breast-fed babies are at lower risk for sudden infant death syndrome and serious chronic diseases later in life, including asthma, diabetes, leukemia and some forms of lymphoma."

In the AAP primary scientific position statement (hosted on the front page of their breastfeeding page), the organization states "Extensive research using improved epidemiologic methods and modern laboratory techniques documents diverse and compelling advantages for infants, mothers, families, and society from breastfeeding and use of human milk for infant feeding. These advantages include health, nutritional, immunologic, developmental, psychologic, social, economic, and environmental benefits."

We decided to take a closer look at these claims than the Times did; the real story is both surprising and reassuring. We start with the scariest question first: Will babies die if they are not nursed? According to the American Academy of Pediatrics (AAP), breastfeeding leads to a 21 percent decrease in the death rate of babies in an age range over one month and under one-year old. But turn to the AAP's source. The scientific study used to support this claim found that babies who are nursed are less likely to die. of injuries! While it may be hard to explain away that data, it is hard to believe that the AAP is recommending that exhausted, tired, guilt-ridden, and otherwise strung out mothers nurse because otherwise, their child might end up falling off a table.

There is, in this paper, a weak association between nursing and a reduced risk for Sudden Infant Death Syndrome (SIDS). But the association is not statistically significant (the 95 percent confidence interval is .67-1.05). And since there is no obvious mechanism for this either, we are left wondering whether this is because breast milk (possibly in a bottle) helps reduce the risk, or whether it's the physical attention obtained by being nursed frequently during the night, or whether it's that nursing babies are sleeping with their parent more. If it's the latter, for example, then we should advocate co-sleeping rather than nursing. Finding this kind of poor science behind a huge AAP campaign to promote breast milk and nursing over formula got us wondering. What other wives tales are out there?

Let's be honest: if the only adverse consequence of not nursing is that babies get a few more colds, we could leave the decision making to the parents. The real question is whether there are dangerous or potentially long-term damaging illnesses (such as ear infections that lead to hearing loss) for babies who aren't nursed versus babies who are. And how long (or how much) should a baby be nursed in order to keep his or her risk down?

One of the big problems in trying to assess this question is that not all nursing is equal. There are mothers who nurse exclusively, mothers who use expressed breast milk (delivered in bottles), mothers who freeze milk, or use pasteurized (donated) milk, or use some breast milk and some formula, and a combination of all of the above. Then there are the babies, some of whom are premature, or have low birth weight, or have other health issues that could make nursing harder; there are some babies who are nursed until they are four-years old, and others who nurse until they are six-weeks old.

Finally, we must add a complicating factor that it's virtually impossible to carry out the gold standard of research on this issue - a case-controlled study in which mothers are randomly assigned whether to nurse or not. Our observational power may also be limited; at least in principle, because women (and families) who nurse are not the same as those who don't, making any comparison of the outcomes extremely difficult.

But even if we accept these difficulties and try to assess the literature, the picture is not as clear as that painted by the AAP. We found several incidents, like the death-by-injury statistic, which suggested the organization was exaggerating the findings in the literature. Many of the papers referenced were done in the 1980s, when medical care, daycare, and social contexts were significantly different from those today. Perhaps more importantly, studies done in the 1980s did not control for all the factors (such as whether the parents smoke) that we now know have an important impact on infant health. Other studies - especially more recent papers - simply didn't find what AAP claimed they did.

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