A Changing Environment and the Increasing Prevalence of Celiac Disease
Research studies in the United States and Europe show that celiac disease is significantly more common now than it was a few generations ago. Research by Joseph Murray, M.D., professor of medicine at the Mayo Clinic in Rochester, MN, and colleagues showed that this shift reflects an actual increase in prevalence, not merely a new awareness of the disease and more accurate diagnostic tools. Murray and colleagues’ research compared blood samples collected 50 years ago from more than 9,000 young adults, mostly men, at Warren Air Force Base in Wyoming with current samples from age-matched men. The investigators found that celiac disease is four times more common today than a half-century ago. The increase cannot be a result of changes in the genetic factors that underlie celiac disease, Murray explained. “Of course, human genetics will change in response to the environment, but that change is extremely slow. It’s far more probable that the increase is due to an environmental change, and the most likely factor is a change involving the grain in our diets,” Murray said. “Consumption of wheat has increased steadily over the past 50 years, but it still is less than what it was a century ago, so the issue is not simple consumption,” Murray noted. “It more likely involves the wheat itself, which has undergone extensive hybridization as a crop and undergoes dramatic changes during processing that involves oxidizers, new methods of yeasting, and other chemical processes. We have no idea what effect these changes may have on the immune system.”
A second environmental factor that may be contributing to the increase in celiac disease is what is known as the “hygiene hypothesis,” explained Murray. This theory proposes that the developing immune system has to be stimulated by exposure to infectious agents, bacteria, or parasites in order to develop properly. An increasingly clean environment reduces the number of factors that challenge and stimulate the developing immune system, making infants and children more susceptible to immune disorders and allergic diseases. The hygiene hypothesis may account, in part, for the increases observed not only in celiac disease, but in other allergies and immune disorders. “Diet and hygiene both may play a role in the increase. There no doubt are multiple environmental factors that interact to trigger the onset in people who are genetically predisposed,” Murray said. “The increasing prevalence makes it more important that health care providers and patients are alert to the possibility of celiac disease.”
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Page last updated September 24, 2014