Eat dirt to protect against toxins, parasites

A new study has given the most likely explanation for the man geophagia - eating earth - it protects the stomach against toxins, parasites and pathogens. The first written mention of the man comes geophagia Hippocrates over 2,000 years, said Will Young, a researcher at Cornell University and lead author of the study.

Since then, consumption of soil have been reported on every inhabited continent and in almost all countries. Despite its ubiquity, scientists have so far been unable to definitively explain why people crave the field. Several hypotheses have been considered as plausible.

Some researchers have theorized that the Earth has a protective effect, working as a shield against the ingestion of parasites, pathogens and plant toxins. The study analyzed the youth and his colleagues reports of missionaries, doctors planting, explorers, anthropologists and compile a database of more than 480 cultural geophagia. The database contains much information as possible about the circumstances in which the Earth has been consumed and by whom. Overall, the Cornell researchers found the hypothesis of protection adapted to better data.

Database shows that geophagia been documented for most women in the stages of pregnancy and in pre-adolescent children. The two categories of people are particularly susceptible to pests and pathogens, according to Young and his colleagues. 

In addition geophagia most common in tropical climates, where food-borne microbes are abundant.

Finally, the database shows that people often eat dirt during episodes of gastrointestinal stress. Further study would be useful to confirm the hypothesis of protection, but the data available at that time clearly supports further explanation, the researchers said. The study will be published in the June issue of The Quarterly Review of Biology.