Eating Dirt and Terra Sigillata
Jun07

Eating Dirt and Terra Sigillata

“A cloak of loose, soft material, held to the earth’s hard surface by gravity, is all that lies between life and lifelessness.” — Wallace H. Fuller, Soils of the Desert Southwest, 1975 Dirt is a paradox. Children playing in the dirt all day are admonished to wash their hands before eating dinner. But eating dirt, or geophagy, has been pervasive throughout centuries and across diverse cultures. I learned last week while at the Santa Fe Science Writing Workshop that northern New Mexico is home to soils used for religious purposes. El Santuario de Chimayo, a Catholic shrine and pilgrimage destination, is home to a small pit of soil called El Pocito. Legend has it that in 1810 a local friar saw light bursting from a hillside and found a crucifix when digging to identify the source. Since then the soil in the hole has been believed to impart healing properties. The legend is so pervasive that Gerald Callahan used the story to launch a 2003 article in Emerging Infectious Diseases, a publication of the US Centers for Disease Control and Prevention. But one needn’t make a pilgrimage: you can order your holy dirt of Chimayo here. Alas, one is advised today that the dirt is not to be eaten or drunk, although other information on the website indicates that has been on use of the soil. Twitter follower and Charlotte-based CEO of Molecular Creativity, David Bachinsky, alerted me the other day to a press release on a forthcoming paper that explores the reasons for eating dirt. Sera Young and colleagues at Cornell University explored nearly 500 cultural accounts from missionaries to anthropologists to determine the most likely of the three choices. The analysis will appear next month in a Quarterly Reviews in Biology entitled, Why on Earth?: Evaluating Hypotheses about the Physiological Functions of Human Geophagy. Three main hypotheses have emerged to account for this practice first described by Hippocrates over 2,000 years ago: To reduce the pangs of hunger To provide minerals lacking in the diet To protect against parasites, pathogens or naturally-occurring toxins My apologies to the reader that I am only going off a press release but I have requested the embargoed original paper since this topic is near and dear to this blog. I’ll discuss the hypotheses and outcomes in another post after I’ve read the paper. However, my interest was also piqued by mention that Young has also written a book for popular consumption (pun intended) entitled, Craving Earth: Understanding Pica — the Urge to Eat Clay, Starch, Ice, and Chalk. But this story also gives me the opportunity to repost the original explanation of how I chose Terra...

Read More