In celebration of Earth Day it seems fitting to reflect on the eaters of earth – those people who crave big chunks of our planet in their daily diet, whether in the form of freshly dug clay, a piece of the mud hut nibbled in the afternoon, or mud from the river bed.
Sound bizarre? Indeed, the Diagnostic and Statistical Manual of Mental Health Disorders (DSM) lists “geophagia” – the compulsive desire to consume earth, soil or clay, as a mental disorder. Subsumed under the broader category of “Pica” (the desire to consume non-nutritive substances including plastic, iron, newspaper, toilet paper, paint chips and the like), geophagia has a long history as a dietary practice, being recorded as far back as the 4th century BC by Hippocrates.
No one really knows what causes geophagia, but it is known that it is more prevalent among certain groups in Africa, some African Americans, rural Appalachians, women, children, and some groups in Southeast Asia. One of the reasons so little is known about the causes of geophagia is that there have been few interdisciplinary studies focusing on how culture, environment, physiology and soil science intertwine in the etiology of the behavior.
Cultural anthropologists have tended to focus on “culture” as the primary cause (either viewed as ignorance about dietary needs, or a “traditional” means of meeting dietary needs). Epidemiologists have tended to focus on the public health concerns of geophagia (which are significant), while evolutionary biologists have focused on earth eating as an evolutionary mechanism to protect against famine, provide micro-nutrients, and absorb harmful toxins and pathogens (the things that make us sick).
In her book, Craving Earth: Understanding Pica, the Urge to Eat Clay, Starch, Ice and Chalk, anthropologist Sera Young argues that multiple factors influence geophagia, and that not all forms of pica have the same origins, etiology or consequences. Her book is filled with lively accounts of people who crave clay from specific regions, displaying a connoisseur’s sophisticated palate as they discuss the tastes, textures and aromas of differing types of earth. Earth eaters are known to smuggle prized clays from distant regions, remain secretive about their favored sites for good earth eating, or even buy it online. Sam’s General Store in Georgia, for example, sells “White Dirt of Georgia” which they advertise as “The Original Freshly Dug Georgia Gourmet White Dirt.”
Another form of geophagia is the eating of starch, most commonly corn starch. Starch eating is generally considered a substitute for earth eating. When people could not get the smooth, rich clay they were accustomed to eating, they turned to eating chunks of starch – which could be discretely pocketed or tucked away in a purse for nibbling throughout the day. In fact, one of the reasons corn starch manufacturers converted their product to a powder form was to discourage this form of eating.
Amylophagy, starch eating, and Geophagy, earth eating, may have serious health consequences including contributing to anemia, causing intestinal blockages, eroding tooth enamel, and causing high levels of lead poisoning. But other health benefits have been noted. Starch is high in calories, and both starch eating and earth eating may have helped populations survive during famine. Clay also absorbs harmful toxins and pathogens, which may explain in part why it is so prevalent among pregnant women. During periods of rapid growth, such as organogenesis (when the organs of the fetus are developing), earth eating may have protected against parasitical diseases and toxic exposure.
But don’t rush right out to your garden and eat a bucket of dirt just yet. Earth Day is a reminder of how degraded our earth has become, and that includes our soil and groundwater being heavily contaminated with chemical toxins and radiation far beyond any natural levels. To find out what is in your earth and water, check out the website for the Environmental Working Group where you can find out just what pollutants are being released in your neighborhood. It’s sure to kill any cravings for a fistful of dirt and send you straight to the kitchen for some good old fashioned comfort food!