Craving Earth: Understanding Pica. The Urge to Eat Clay, Starch, Ice and Chalk

Sera L. Young

Review by Olutoyosi Tokun

Sera L. Young, the author of Craving Earth: Understanding Pica, defines pica as the craving and purposive consumption of items that the consumer does not consider to be food for more than a month. Young’s work provides an in-depth description of pica practice; it also evaluates existing hypotheses that seek to explain the reasons why humans engage in pica.

The book was a big eye-opener for me as I did not realise how incredibly wide-spread pica practice is. Apparently human consumption of non-food substances is not unheard of in most parts of the world. This practice cuts across diverse cultural settings. Young reports that pica is overwhelmingly associated with pregnant women such that in certain societies if a woman begins to crave for non-food items, it is assumed she is pregnant. Children have also been identified as an important group of non-food consumers. Hence the need to thoroughly investigate the health consequences of this practice.

Non-food items commonly consumed by humans include; earth, starch, ice, chalk, newspaper, charcoal, toilet paper, ash, flour, paint chips and baby powder. It is interesting that pica substances tend to have similar properties – they are usually dry, powdery and adsorptive – with the exception of ice. One striking thing about people who practice pica is that they insist on particular ‘brands’. For instance for humans who eat earth, it has to be from a particular spot. Geophagists are usually able to tell if the earth supplied is from a different spot. Pagophagists can also be very picky about the source of the ice they crave for.

While reading about geophagy I kept wondering what happens to all the clay that is being ingested by people who engage in pica. Isn’t the eater’s appendix filling up with dirt as the human body is mostly unable to digest it?

One big lesson for me is that a person’s eating habit goes beyond nutrition and appetite; it is usually multi-faceted reflecting the person’s social values, belief system and life experiences. In my culture for instance, medication and medicinal food substances have to taste very bitter for you to be convinced of its potency.

Although there is still a lot of uncertainty around the causes of pica, Young’s book is quite informative and accessible. I thoroughly enjoyed reading it.