Pica: You gonna eat the rock?

Normally, this blog will update on Mondays. Today's post is just to put something up that isn't a piece of one of my research papers. Hope you enjoy.


I was unaware of this particular eating disorder until someone asked me about it at school. Curious I questioned what they were talking about. It was explained to me that some people in the world have an unusual eating disorder that causes them to eat rocks. Now I was aware of certain types of clay being formed into calcium-rich tablets but as for straight up eating clay and dirt I was a bit perplexed and decided to investigate.

Pica is a word derived from the Latin word for Magpie, a bird that is known for eating anything such as worms, animal droppings and rocks. Ther term now is used to describe a particular eating disorder in which people habitually eat things which are generally not considered food - the most common things usually are flour, cornstarch, rocks, clay and dirt. The condition is also called geophagy, which translates to dirt-eating.

Uncommon? Not really, there are cases of it documented throughout the world. Many cultures tout that it has various health benefits, the facts behind this aren't exactly well documented but we'll discuss that later. Often people resort to pica in times of extreme famine or poverty as, theoretically, it supposedly has nutritional values.

The research behind these theories is scanty at best - almost all of the studies have been relatively classist with most of them performed on relatively low income families and very few higher socioeconomic groups have ever been extensively studied.

There are a variety of theories behind it. Paul Fieldhouse in his book Food & Nutrition: Customs & Culture posits the following reasons:

• Psychological - to get attention
  
• Anthropological - traditional behavior taught by mothers to daughters during the process of gardening and food prep
• Sensory - clay eating decreases uterus movements and intestinal mobility and thus reduces nausea, it also reduces hunger
• Microbial - pica influences acidity of intestinal tract, discouraging the growth of pathogens
• Physiological - reduces the amount of saliva in the mouth which is a problem for some pregnant women
• Nutritional - pica provides some nutrient missing from the diet

The two most commonly referred to theories though are the nutritional and the psychological ones. Nutritionally, people supposedly eat clay and dirt in order to balance iron, calcium, or magnesium deficiencies. This is often is poor areas where access to a balanced diets or dietary supplements aren't available.

In regards to the idea of attention getting this theory is usually nulled by the fact that most adults, and in particular pregnant women, don't admit to the habit and struggle to keep it a secret. However, that counter-argument is itself undermined by the idea that each person could be doing it for psychological reasons.

Anthropologically, the behavior is seen as something picked up to stave off hunger during times of famine as previously noted. Sometimes the habit is carried over during times of plentifulness and then is adopted by the medicinal practices of that culture. In the theories of hot and cold medicine (the practice in which medicine is seen as a balancing of temperatures - heartburn, a hot malady, might be treated with mint, which has cooling properties) clay was a neutral medicine able to warm cold maladies or put out hot ones.

Of course, not to say there aren't plenty of risks involved. Lead toxicity is a major problem as lead poisoning which according to emedicine can have neurologic, hematologic, endocrine, cardiovascular, and renal effects. The ingestion of pathogens especially in regards to corprophagia and xylophagia where bacteria and poisonous mycological growths can occur. Obstruction of the digestion tract in regards to the consumption of paper, flour, or starch can also be a serious problem which may result in organ rupture and blood poisoning.

Nowadays you can start buying types of clay and dirt in pill form as a dietary supplement. In fact NASA requires it's astronauts on the space station to take calcium rich clay tablets to assist with keeping optimum bone density in zero gravity. So technically, many people partake in geophagy, but not in a habitual way. Indeed, taking these supplements can help cure the condition and often iron supplements are prescribed which for some helps relieve cravings.

A curious habit to consider. Future studies however still must be conducted over multiple socioeconomic, racial, gender, and age categories to ascertain any real or solid data. The little bit that has been done is incredibly biased and therefore unreliable.


Pica on Wikipedia