Higher gluten levels in new wheat strains are not responsible for an increased prevalence of celiac disease, according to an article in the Journal of Agricultural and Food Chemistry. Overall gluten consumption has increased due to other factors.
Donald D. Kasarda, Western Regional Research Center, Agricultural Research Service, USDA, Albany, CA, cites evidence that the incidence of celiac disease increased during the second half of the 20th century. Some estimates indicate that the disease is four times more common today. Also known as gluten intolerance, celiac disease occurs when gluten, a protein in wheat, barley and rye, damages the lining of the small intestine, causing a variety of symptoms. There is no current explanation for the increased prevalence of the disease. One leading possibility had suggested it results from wheat breeding that led to the production of wheat varieties containing higher levels of gluten.
Kasarda's perspective article examined the scientific evidence for that hypothesis and found that gluten levels in various wheat varieties have changed little on average since the 1920s. Overall gluten consumption has increased. Consumption of "vital gluten" has tripled since 1977. Vital gluten is a food additive made from wheat flour and is added to various food products to improve characteristics such as texture. Overall consumption of wheat flour has increased 25% over a thirty year period from 1977 to 2000, amounting to an average of 2.9 pounds more per person.
