In several places around the world, pregnant women frequently engage in pica — a scientific term for the craving and consumption of various items that are not food, most popularly earth, clay and rocks. In a book talk on Nov 3 in Mann Library, researcher Sera L. Young, nutritional sciences, discussed her book, Craving Earth: Understanding Pica. Young detailed the search for an explanation of why some people engage in this behavior and what properties some of the consumed substances possess.
While in the past there have been various theories that tried to explain why pica occurs, Young’s research suggests that there are several health benefits for those who engage in this behavior.
To find answers, Young and her team of researchers examined more than 400 cultural reports of dirt-eating in places like Malawi, Zanzibar, New Delhi and even Mississippi. Looking for patterns, Young and her colleagues tried to find similarities among those that practice pica, and noticed several different things.
For example, Young explained that pregnant women compose the largest population of consumers.
“Pica is so overwhelmingly associated with pregnancy that in some places [like Malawi] it is synonymous with pregnancy,” she said. Children, especially pre-adolescents, compose the second largest group of consumers.
“Young children are the second most likely to consume non-food substances, although there are far fewer anecdotal reports of their pica behavior than for pregnant women,” she said.
In her book, Young creates a framework for pica, explaining some of its relevance in a religious and historical context. For several religions, for example, pica dates back to ancient times. In Hinduism, pica is historically significant because Krisha, a central figure of the religion, ate earth.
“One day, one of the neighbors complained to Krishna’s foster mother, Yashoda, that Krishna was eating dirt,” Young said.
Though some theories suggest that people often turn to pica when they do not have enough to eat, Young and her colleagues found that people eat dirt –– typically boiled first –– even if they have sufficient access to food, and those who do it rarely eat enough to make themselves full.
Other theories suggest that people practice pica to supplement certain nutritional deficiencies. However, the most common form of dirt eaten, clay, has no nutritional value and can actually put a strain on the uptake of nutrients by the digestive tract, Young said.
According to Young, the most promising explanation for pica is that consuming dirt protects the body against parasites and pathogens by blocking them from the digestive tract. Because both young children and pregnant women are particularly vulnerable to germs and various parasites, this theory would support their strange cravings.
“This clay can either bind to harmful things, like microbes, pathogens and viruses, that we are eating, or it can make a barrier, like a mud mask for our gut,” Young said.
Furthermore, pregnant women and children are typically more vulnerable to malnutrition and bacterial infection, which are found in hot, moist areas like Africa, where 30 to 60 percent of women crave dirt during pregnancy. Young and her colleagues found that pica is much more common in these types of climates, which suggests that people may be turning to pica to curb some of their other digestive problems.
Despite some of the potential benefits, the consumption of any non-food items is a risk that can often lead to several harmful effects on the body. Dangerous health conditions that may result from pica include dental damage, lead poisoning, gastro-intestinal damage and, most commonly, anemia.
“Pica is associated with anemia far more frequently than it is with any other negative health condition. I would estimate that there are twenty case reports of anemia associated with pica for every one report of any other negative health outcome,” Young said.
Young’s book examines the practice in the hopes of explaining it to people and helping those for whom pica is a problem. Designed to be appealing to all kinds of readers — not just those with an intimate knowledge of nutritional, soil, or biomedical sciences — the work serves a very important purpose.
“Contextualizing this, making it clear to people that it’s not such a weird behavior,” Young said, “will help women come forth and not feel so alone.”