Sera Young — Craving Earth

Recently Sera Young’s Craving Earth: Understanding Pica–the Urge to Eat Clay, Starch, Ice, and Chalk, has received attention from a variety of sources.

The Week summarized some of the key elements of pica described in Young’s book, including the desire some pregnant women have for dirt, and why other non-food items are eaten.

The popular site Boing Boing also featured the book:

Apparently, this phenomenon [eating pica] happens all over the world, primarily to pregnant women. In fact, says author Sera Young, in some cultures eating dirt is the go-to pregnancy “gotcha” symptom—the same way that every American knows to suspect a woman who pukes in the morning, or wants pickles with her ice cream.

That’s really where a lot of the fascination comes from for me. Why is this tendency so specific to pregnant women? And why does the frequency of pica vary depending on location? Even though people do this all over the world, studies have shown some big differences between populations. For instance, Young writes, .01% of pregnant Danish women eat dirt, but 56% of pregnant Kenyan women do.

There’s clearly some interesting overlaps between biology and culture happening here. Do the lower numbers of Danish pica practitioners, compared to Kenyan, reflect differences in genetics? Does this say something about the differences in diets between developed and undeveloped countries? (An interesting train of though, as Young points out that pica was widely known and accepted by American women in the rural South as late as the mid 20th-century.)