Eat dirt – it’s good for you!
9 Jun 2011 by Evoluted New Media
As a child, you’re always told not to eat dirt but geophagy – the eating of earth – is common in many parts of the world. It’s happened on every inhabited continent and in almost every country.
As a child, you’re always told not to eat dirt but geophagy – the eating of earth – is common in many parts of the world. It’s happened on every inhabited continent and in almost every country.
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Eating dirt as a child isn’t necessarily bad for you! |
Extensive meta-analysis performed by researchers from Cornell University has revealed people ingest dirt to protect against toxins, parasites and pathogens. They analysed reports from missionaries, plantation doctors, explorers and anthropologists to construct a database of more than 480 cultural accounts of geophagy. They included as many details as possible about who ate the earth and why, and used patterns in the data to evaluate each potential explanation.
Scientists’ first explanation was geophagy was consequence of food shortages and eating dirt eased hunger – even though it provides no nutritional value. However, the practice is common, even when food is in plentiful supply, and the quantity of dirt eaten was too small to fill an empty stomach.
Some scientists believe people eat dirt for its nutrients – in particular iron, zinc and calcium. Reports indicate geophagy may be associated with anaemia but cravings for earth still continue after people are given iron supplements. Researchers rejected this hypothesis because the clay-based earth most often eaten contains low amounts of nutrients.
The final hypothesis seemed to fit the data the best – people eat dirt to protect their stomachs against toxins, parasites and pathogens. Geophagy is documented most commonly in women in the early stages of pregnancy and in pre-adolescent children – both of whom are sensitive to parasites and pathogens.
The practice is most common in tropical climates where foodborne microbes are abundant. The database shows people eat earth during times of gastrointestinal stress.
Researcher say more study is needed to confirm this is the correct hypothesis, but it is the most likely.
“We hope this paper stimulates more research,” said lead author Sera Young, “More importantly, we hope readers agree that it is time to stop regarding geophagy as a bizarre non-adaptive gustatory mistake.”
“It is clear that geophagy is a widespread behaviour in humans, that it occurs during both vulnerable life stages and when facing ecological conditions that require protection.”
