How common is celiac disease? At one time, medical students were taught that only one person in 5,000 had this condition in which a reaction to gluten damages the intestinal lining. Gluten, a protein in wheat, barley and rye, can trigger non-specific symptoms such as joint pain, anemia or fatigue in susceptible people as a consequence. A survey of 7,800 Americans used blood tests to find that 35 of these had celiac disease. That works out to a rate of one in one hundred Caucasians. The majority were unaware that they were sensitive to gluten. The treatment for celiac disease is to avoid gluten in the diet.