Pica is the constant urge to eat things that have little or no nutritional value. Apparently this wasn't treated as a disorder right away.
"Clay eating and soil eating were common in the 1800s, especially among slaves in the South. In the 1950s and 1960s, the practice was so popular that clay-filled lunch bags were sold at Alabama bus stops as snacks for travelers. Southerners mailed bags of hometown clay to their friends and relatives who moved north. Some reports estimate that clay eating is a daily practice in over two hundred cultures worldwide."
For the cultural aspect, some cultures believe that pica can have medicinal purposes. They aren't exactly wrong. In Nigeria, people eat clay to combat diarrhea. The clay actually lines the intestines and stops the bacteria from spreading. When the person's culture treats pica as an everyday thing, people gradually don't know where the line is drawn between food and non-food.
As for the mental aspect, some doctors claim that pica is caused by OCD or schizophrenia. Some people claim that when they do this, they feel less anxious and more relaxed.
Although pica is a part of certain cultures in the world, and sometimes to be proven to have medical values, this does not mean there are no consequences when doing this. Pica is not something fun to try when you're bored or to impress a certain someone. It's a strange eating disorder that comes with many risks and dangers.
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