By Charlotte Evans
My parents have a story of my brother eating dirt as a young child that never fails to make me laugh and make him embarrassed. It’s a common experience as parents, trying, and sometimes failing, to stop their kids from putting everything imaginable into their mouths. But what if that behavior continues? What would you do if you saw an adult eating a spoonful of dirt?
This phenomenon is called “pica”, and it’s much more common than you’d think. Pica is defined as “the craving and purposive consumption of substances that the consumer does not define as food,” and can include things like dirt, raw starches like uncooked rice, chalk, paper, and ashes (Lin et al., 2015). Technically, even ice-eating is considered pica, and is the most common manifestation of the disorder, but ice’s non-food status is more debatable than other common items. It’s easy to see how pica could be unhealthy; non-foods like dirt or paint-chips might contain toxins, they don’t contain normal nutrients, and can cause blockages in the intestines. There are, however, some interesting claims that pica may be beneficial in reducing nausea or providing micronutrients that a normal diet does not contain (Lin et al., 2015).
A study by Lin and colleagues (2015) on recently or currently pregnant women in southern California and Mexico found a relatively high incidence of pica, especially while pregnant. All participants understood the craving for inappropriate items, and reported that even if they didn’t engage in the practice, they knew others that did. Pica is most prevalent in children and pregnant women, where it is estimated that up to 50% eat a non-foodstuff at some point during their pregnancy. Pica is also more common among non-white women and immigrant populations, suggesting a cultural factor alongside a biological or psychological craving to eat non-food (Lin et al., 2015).
The most common non-foods consumed by these women were particular kinds of soil, clay, the stones found among uncooked beans, uncooked rice, and magnesium carbonate cubes purchased from a pharmacy. The main appeal was the smell of these items, but the women also reported attraction to the texture of the non-food, and beliefs in personal nutrient deficiencies. These factors are commonly referenced in non-pregnant women also. This study also uncovered a cultural element to pica in that the women held superstitions about their children being born with birthmarks or altogether aborted if they didn’t give in to the craving (Lin et al., 2015). This belief is not unique to this cohort, as this superstition seems to be an ancient pregnancy myth and is also reported in Egypt, Israel, and Italy, where it’s believed the shape of the craved food will appear on the child’s body in the form of a birthmark (Khazan, 2015).
The findings of the study are particularly intriguing for several reasons. First, the potential harm done to the women and the children they’re carrying by ingesting toxins or parasites objectively far outweighs the personal benefits of giving in to a craving. Some women gave in despite being aware of the risks (Lin et al., 2015), and this may be due to cultural norms around pregnancy. Second, the nutrient deficiency theory is countered by findings in other studies. According to a paper by Intiful, Wiredu, Asare, Asante, & Adjei (2016), zinc, iron, and calcium deficiencies are common in individuals practicing pica. They found that of the pregnant women with pica they tested, 83% were anemic - 1.23 times the rate of non-pica pregnant women. Thus, the practice of pica likely contributes to the deficiency, as the substances in non-food can make it harder to ingest and extract nutrients from real food, making the practice by these women ironic and dangerous to their health (Intiful et al., 2016).
In light of these recent findings on the prevalence, causes, and dangers of pica, the next step is education about its dangers, especially for pregnant women. But even with greater educational awareness, how do you stop yourself from giving in to what you want, even if you know it’s bad for you? Once you give in, how likely are you to eat a non-food again? And what if your culture makes your craving acceptable, as with the superstitions surrounding pregnancy? In short, how can we rid ourselves of our vices that are biological, psychological, and cultural?
Intiful, F. D., Wiredu, E. K., Asare, G. A., Asante, M., & Adjei, D. N. (2016). Anaemia in pregnant adolescent girls with malaria and practicing pica. The Pan African Medical Journal, 24. https://doi.org/10.11604/pamj.2016.24.96.9282
Khazan, O. (2015, April 8). The odd superstition behind birthmarks. The Atlantic. Retrieved from
Lin, J. W., Temple, L., Trujillo, C., Mejia-Rodriquez, F., Rosas, L. G., Fernald, L., & Young, S. L. (2015). Pica during pregnancy among Mexican-born women: A formative study. Maternal & Child Nutrition, 11(4), 550–558. https://doi.org/10.1111/mcn.12120