Tuesday, June 27, 2006

World's Biggest Conversation on Breastfeeding

I've been behind on this blog, particularly on updating the links. Effect Measure and Living the Scientific Life are now part of ScienceBlogs, whose mission is to hold the "world's largest conversation about science."

Two weeks ago the conversation turned to breastfeeding. The occasion was an article in the NY Times outlining a public health campaign to encourage new mothers to breastfeed for at least six months, by highlighting the health benefits of breast milk.

I have long been in awe of the biological properties of breast milk, since I read Karen Pryor's Nursing Your Baby. The Times article cited what was, for me, a new perk of breastfeeding:
But while formula tastes the same way at every feeding, advocates of breast-feeding say, the smells and flavors of human breast milk change from day to day, from morning to evening, influenced by the mother's diet. Many nutritionists believe that exposing an infant to this bouquet of flavors early on may make for less fussy eaters who are more flexible about trying new foods and more likely to eat a healthy, varied diet.
Does this explain why my kids are such adventurous eaters?

I jumped into the conversation, posting here, here, and here. But I'm disappointed with the conversation itself. Somehow when you talk about breastfeeding, even among scientists, it degenerates into dueling anecdotes and working mom war stories. Rather than focusing on the unique anti-infection components of breast milk, the conversation is centered around studies that seek to prove that breast-fed babies, as a population, are healthier than bottle fed babies.

Human beings are lousy test subjects. We want our privacy, tend to fudge when we are asked to report on our own behavior. We won't be forced into categories like "100% breast feeding" and the variations in our behaviors are enough the screw up any study. Plus the world we live in is changing in uncontrolled ways.

Last fall I wrote about the changing winds of parenting advice, including a new study that showed that seeping all night in the parents' bed correlates with an increased chance of Sudden Infant Death. That's bad news for breastfeeding, because nursing through the night is a wonderful alternative to getting up and fixing bottles. In March, Richard and I had occasion to go mattress shopping for the first time in 20 years. The mattress salesman, a veteran of the trade, told me that the market has changed in the last 20 years: back then, everyone wanted firm matresses because they were best for one's back. Now everyone buys pillowtops. We bought a pillowtop because it felt good in the showroom. Once we got it home I found that the longer I lay on it, the more it seemed to sag. I would never let an infant sleep on that mattress, it's too soft. I wonder if the "new" findings on co-sleeping are actually new findings on the effects of America's mattress buying habits on infants.

I'm guessing that devising a study to quantify the benefits of breastfeeding by comparing populations is an enterprise doomed to failure. Parenting is just too variable. But adopting the opposite stance, maintaining that formula is just as good as breast milk, requires one to claim that the antibodies, white blood cells, and hormones in breastmilk are useless. That we have evolved past our need of them.

I remember the news clip of the stranded mom in New Orleans crying because she hadn't had any formula to give her baby for two days. We haven't evolved all that far.

I think that breastfed babies do grow up to be smarter. (I'm biased, of course, but that doesn't mean I'm wrong.) We know that well-exercised brains grow better than bored brains, and breast feeding is a much more interesting activity than drinking from a bottle. You face the breast while nursing; very young infants soon learn to slide their eyes to left or right to see Mom's face. You have to work harder to get milk from the breast. The taste of the milk changes from day to day and even from minute to minute. The first milk to come in a nursing session is thin and sweet "fore milk". High fat-content "hind milk" comes in those lazy, sleepy moments to the baby who keeps nursing on a full tummy. Breast milk doesn't come all at once; baby has to learn to suck nicely for a minute until the mother's "let down" reflex kicks in. Work brings pleasing results. Every baby experiments with biting (or hard gumming) the nipple, with alarming results. I can't think of a more rudimentary basis for intelligence than the knowledge that the world consists of cause and effect. Breast feeding is a human's first task, the first cooperative relationship. The alternative universe of bottle feeding is built on the foundation of "cry and you'll eventually be attended to."

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