Historically, oats were restricted from the gluten-free diet because it was thought that their avenin prolamin caused intestinal damage similar to that caused by the proteins in wheat, rye and barley. However, the main reason for reactions to oats is that they frequently are contaminated with gluten-containing grains during seeding, growing, harvest, storage, transportation and milling. Thus, consumption of regular commercial oats is not safe for individuals with celiac disease. Fortunately, there are companies around the world that produce gluten-free oats, although the methods used vary among growers and millers.
Based on clinical studies over the past 20 years, research has revealed that consumption of pure, uncontaminated oats is safe for the majority of individuals with celiac disease. More information about oats can be found from these sources:
Health Canada: Celiac Disease and Gluten-Free Claims on Uncontaminated Oats
Canadian Celiac Association: Professional Advisory Council Position Statement on Consumption of Oats by Individuals with Celiac Disease
Gluten Free Watchdog: Site hosted by dietitian Tricia Thompson, MS, RD