"The reasons for the increasing prevalence of celiac disease over time will need further study," Dr. Rubio-Tapia told me. "Human genetic changes are extremely slow, unlikely to happen in only 50 years, thus the most likely explanation may be environmental."
Dr. Rubio-Tapia referred to what is sometimes called the "hygiene hypothesis." Over time, he explained, most people have been living in cleaner environments compared to their ancestors, and these cleaner environments have resulted in changing patterns of childhood infection. A cleaner environment, Dr. Rubio-Tapia said, may lead "to fewer infections but more allergic and/or autoimmune diseases....Recent data from Europe support this theory in celiac disease. The prevalence of celiac disease was lower in Russian Karelia (on the border with Finland) with inferior prosperity and [standards of hygiene] than in Finland."
However, Dr. Rubio-Tapia said, "I think that the 'hygiene hypothesis' is likely only a partial explanation because celiac disease is a global health problem that affects both developed and developing countries.... Also, there is evidence that certain infections such as rotavirus may increase the risk of celiac disease in genetically predisposed individuals. So, the interaction between humans and infectious microorganisms is very complex and certainly different in each person."
He continued: "Finally, as celiac disease is triggered by gluten, we can speculate that maybe some changes in gluten such as patterns of consumption, processing or preparation of gluten-containing foods might be factors; however, extensive scientific evidence are lacking and (any such change) remains to be proven experimentally."
"Ultimately, the increasing prevalence of celiac disease over time may be the result of several of (these) factors acting together to cause damage of the intestine in genetically susceptible persons," Dr. Rubio-Tapia concluded.
