Thursday, May 30, 2013

Some thoughts on weaning: Shakira and the Neaderthal

Greetings, and welcome to my inaugural blog post. EA is still in Nepal – in Kathmandu, last I heard – and I’m settling in and trying to find my blogging voice. As EA said, I’m a cultural anthropologist, which in my case means not only keeping up with the scientific journal articles about breastfeeding but also looking at  the ways breastfeeding is talked about in popular media. I had been contemplating writing about weaning even before checking the news today, but reading about Shakira's desire to breastfeed her son "until he goes to college" clinched it. Yes, I'm pretty sure she was joking, but she wouldn't be the first celebrity to breastfeed past a year or two. Mayim Bialik (Big Bang Theory) nursed her second son until he weaned this February at age four, a fact she wrote about publicly and triumphantly.

But before this blog deteriorates entirely into a synopsis of Us Magazine articles (probably not what EA intended), I'll note that the original inspiration for a blog entry on weaning was this article from Nature by Austin et al. (2013), about using barium-to-calcium ratios in tooth enamel to determine when nursing infants began to eat supplemental foods and when they stopped breastfeeding altogether. Although the bulk of the research was based on the teeth of humans and macaques with known weaning ages, perhaps the most interesting piece was an analysis of the tooth of a young Middle PaleolithiNeanderthal. According to the barium distribution, the infant began eating supplemental foods at seven months and weaned entirely at fourteen months. This is younger than most researchers would have suspected, based on what we know about weaning ages in non-industrial societies. Of course with an n of one one can't really draw general conclusions - it's possible the infant's mother became ill or died - but it's an intriguing finding nonetheless.

So, how long should a child be breastfed? How long is too long - college? four? - and how long is not long enough? The American Academy of Pediatrics last year reaffirmed its declaration that breastfeeding should continue for a minimum of one year and "as long as mutually desired by mother and baby", although only about 25% of babies in the U.S. meet this goal. Katherine Dettwyler's classic 1995 piece A Time to Wean: The Hominid Blueprint for the Natural Age of Weaning in Modern Human Populations (summarized on her website) suggested that if weaning was not influenced by culture, humans would wean somewhere between age 2.5 and 7. But of course, weaning in humans is influenced by culture, as is breastfeeding itself (the concept of breastfeeding as both a biological and a social and cultural practice is summarized well in the first few pages of this 2012 article by Fouts et al.). Last year's Time magazine cover showing a women breastfeeding her 3 year old son ignited a storm of controversy and a slew of negative comments calling the practice everything from attention-seeking and tacky to abusive (examples in this article and in these comments). Dowling and Brown (2013) echo this finding in their recent study of  British mothers who breastfeed longer-term (which they define as more than six months). These women report accusations that they were hurting their children or enjoyed pain, and felt that many saw their breastfeeding as bizarre or comical - even though many were actually breastfeeding for a shorter time than suggested by medical authorities.

Finally, another recent study found that sixty percent of U.S. women surveyed weaned their children before they wanted to (Odom et al. 2013). I found it significant that many of the problems associated with early termination - cracked nipples, perceived poor weight gain and insufficient milk, pain during breastfeeding - could potentially have been managed by a competent lactation consultant. Perhaps, in western countries with clean water and access to artificial baby milks (infant formula), the focus should shift from telling women "too long" or "not long enough" to understanding how women determine the optimal length of time for breastfeeding and giving them the tools they need to breastfeed "as long as mutually desired by mother and baby", whether that's 14 months or four years. Not college, though. I'm betting Shakira changes her mind by then.

References

Austin C, Smith T, Bradman A, Hinde K, Joannes-Boyau R, Bishop D, Hare D, Doble P, Eskenazi B, Arora M.(2013) Barium distributions in teeth reveal early-life dietary transitions in primates. Nature doi:10.1038/nature12169

Dettwyler, K (1995). A time to wean: the hominid blueprint for the natural age of weaning in modern human populations. Breastfeeding: Biocultural Perspectives. Hawthorne, NY: Aldine de Gruyter, 39-73.

Dowling, S, Brown, A. (2013). An Exploration of the experiences of mothers who breastfeed long-term: What are the issues and why does it matter? Breastfeeding Medicine 8(1):45-52.

Fouts H, Hewlett B, and Lamb M. (2012) A biocultural approach to breastfeeding interactions
in Central Africa. American Anthropologist 114(1):123-136.

Odom, E. C., Li, R., Scanlon, K. S., Perrine, C. G., & Grummer-Strawn, L. (2013). Reasons for earlier than desired cessation of breastfeeding. Pediatrics,131(3), e726-e732.