Dear Doctor Column, December 22, 2003
Seek Medical Help For Odd Food Cravings
Question:
I've had three pregnancies, and with each one I ate bags of cough drops and boxes of baking soda. With my last pregnancy (twins), I had cravings for driveway dirt. I've always picked up rocks and sucked the dirt off them, even before I got pregnant, but now I scoop up the dirt with spoons and put it in a plastic bag. I eat a lot of it, too, and my Mom tries to get me to stop but I can't. I know I can get a parasitic infection by eating dirt, but would microwaving the dirt first make it safe to eat?
Answer:
What you're describing is known as pica, which is the compulsive eating of various substances that are generally considered inedible, such as dirt, clay, sand, laundry starch, ice, or hair. Sometimes the craving is for a specific food, such as pickles or peanuts, but unlike ordinary hunger, pica is characterized by consumption of extraordinary amounts. Typically, the craving is confined to a single substance.
Actually, pica is somewhat common in children, but it's much rarer among adults, occurring most often among pregnant women or people with mental retardation. People suffering from autism, schizophrenia, and other serious mental illnesses also may consume inedible substances, but their behavior is attributed to their major illness and is not considered to be true pica.
The exact cause of pica is unknown. Physiological explanations center on possible nutritional deficiencies. Iron deficiency, for example, is cited as the most common cause of craving for ice, referred to as pagophagia. In addition, iron deficiency has been blamed for clay-eating among pregnant women. Sometimes a deficit in other trace minerals, such as copper, is believed to be the cause. However, in most cases, no specific physiological abnormality can be detected.
Cultural factors sometimes play a role, as well. Some experts suggest that among certain ethnic groups, the eating of earth or clay (called geophagia) is culturally accepted and associated with certain beliefs, other than psychological or medical causes.
Understandably, pica can be dangerous. The degree of danger depends on the nature and quantity of the substance that is eaten. One of the most common complications is lead poisoning, associated with eating lead-based plaster and paint. Eating dirt, sand, hair, and laundry starch can cause bowel obstruction. Consumption of sharp objects, such as glass, may lead to serious gastrointestinal tract injury. Eating dirt or grass can result in parasitic infections, as you mentioned. Typically, people are not seen by a doctor until friends or relatives report the disorder or unless the person develops medical complications.
If a large amount of an inedible substance has been consumed, the doctor may have to administer emergency care. Once any acute complications are handled, the doctor orders tests to determine whether a nutritional deficiency may be causing the pica. Nutritional supplements are sometimes effective, particularly if the craving for ice is associated with an iron deficiency. In addition, the person may need help from a mental-health counselor.
If nutritional supplements and simple counseling fail to help, the doctor may recommend behavior therapy, which often proves effective. Aversion therapy, a form of behavior modification, seems particularly effective in treating adult pica. This therapy links a negative stimulus, such as a mild electric shock, with the craved substance. The objective is to discourage the person from consuming the substance by making it unpleasant. Another method uses positive reinforcement, in which the patient receives a reward, such as social recognition or a present, for refraining from eating the substance they crave.
Pica that appears during pregnancy usually disappears after the baby is born. Whenever a pregnant woman has strange cravings, she should talk to her doctor, especially if she craves harmful substances. We encourage you to see your obstetrician right away.