Cereal Foods and Celiac Disease
~ April 2007 No.214 ~
According to the Canadian Celiac Association, approximately one in 133 Canadians is affected by celiac disease. Celiac disease, also known as gluten sensitive enteropathy, is a dietary intolerance disease of the small intestine which is characterized by damage to the small intestinal mucosa resulting in malabsorption of nutrients. The disease was first reported in 1888 by Samuel Gee who described the features of the disease with remarkable accuracy and even suggested that the cure might be found in the diet. In 1950, wheat was reported as the trigger component in celiac disease. Wheat proteins, particularly gliadins and its peptide digests, are known to cause the mucosal damage associated with celiac disease. Other similar alcohol soluble proteins called prolamins from rye, barley and triticale are also found to cause the damaging effect in the celiac small intestine. These cereal foods (wheat, durum, barley, rye and triticale) must be avoided by celiac patients.
Spelt is an ancient wheat that was used as a staple food in early Europe. It is more nutritious than common wheat, but still contains gluten proteins and is capable of provoking wheat allergy and gluten enteropathy. Compared to wheat though, it is more easily digestible, rich in complex carbohydrates and fibre, and has a higher protein content than wheat. Some people with a wheat intolerance can tolerate spelt, but it is not a suitable substitute for people with celiac disease or wheat allergy and is best AVOIDED. If you have a wheat allergy, consult your doctor before eating spelt.
A lifelong ‘gluten-free’ diet is the only recommended treatment for celiac patients regardless of symptoms. According to the level of gluten sensitivity of the patient, an absolute or tailored gluten restriction will be applied to the diet. The term “gluten” given here by physicians and paramedics means prolamins from grains that are capable of activating celiac disease, and not the dough-forming proteins defined by cereal scientists and bakers. Gluten detection kits have been developed based on enzyme-labelled antibodies for detecting gluten in diets. The antibodies in these tests were selected in order to bind certain prolamin proteins from wheat, durum, triticale, rye and barley, and to react with heat-stable ω-gliadin despite its lower toxicity compared with α- β- and ω-gliadins. The α- β- and ω-gliadins lose much of their antigenicity after heating, especially baking yet retain their toxicity. It is not practical to test for those gliadins in cooked foods. The advantage of ω-gliadin antibodies is that they bind with raw and heat-treated or processed proteins.
Recent attempts to use sourdough lactic acid bacteria as a means to break down gliadin proteins are found to be promising. A 33-amino acid peptide in gluten containing the major immunogenic epitopes that trigger celiac disease in susceptible individuals was resistant to breakdown by all gastric, pancreatic and intestinal proteases in vitro and in vivo. But, it was detoxified by exposure to a bacterial prolyl endopeptidase suggesting a strategy for oral peptidase supplement therapy for treating celiac disease. Addition of a bacterial prolyl endopeptidase caused degradation and loss of the antigenicity of the peptide which would open the possibility to use these enzymes for detoxification of the toxic peptides and developing therapeutic dietary strategies to treat celiac disease.
Ancient wheats such as spelt, einkorn, emmer, Kamut and Khorasan include diverse wheat species having dissimilar genetic makeup. But, all wheats contain gluten proteins that are capable of triggering celiac disease and thus must be eliminated from celiac patient’s diets. The degree of toxicity might be different in these wheats but this postulation has to be investigated. Cereals that don’t activate celiac disease such as corn and rice are being used for making gluten-free foods. Such foods are in great demand since the incidence of celiac disease is steadily increasing worldwide.
Specialty Grains for Food and Feed
American Association of Cereal Chemists 2005,413 pages