The Enigma of Oats in Nutritional Therapy for Celiac Disease

Celiac disease (CD) is a life-long autoimmune condition affecting the small intestine of genetically susceptible individuals. Gluten is one of the offending inducers of the disease, with structurally related molecules found in barley, rye, and oats, where the offending peptides are called avenins. Avoiding toxic prolamins is the only established therapy but most patients have compliance difficulty on a gluten-free diet. Oats are considered less immunogenic than other cereals, and have high nutritional value, which is very desirable in an often undernourished celiac population; however, the consumption of oats by patients with CD is still controversial and debatable. Most clinical and in vitro studies favor oat consumption, but many of these studies were poorly designed and oat cultivar and purity was not considered. A recent study reported a wide range of susceptibility to avenin peptides in patients with CD. Oat cultivars can be subdivided based on toxicity and immunogenicity into none, partial, or highly immunogenic types. Furthermore, most commercial oat products are likely to be contaminated byprolamins. Those products should be avoided by the celiac population and well labeled for contaminants containing gluten. More basic and clinical research and active national celiac associations efforts are needed to characterize the place of oats in a gluten-free diet and to implement non immunogenic and uncontaminated oat products for the benefit of patients with CD. Great care should be taken when recommending consumption of commercial oat products to patients with CD. The most important messages of the review are: 1. Immunogenic oat cultivars are present in oat products. Patients with CD should be cautioned about using them when on a gluten-free diet. 2. Many oat products are cross contaminated with toxic levels of gluten. 3. Interstudy comparisons are difficult because of variability in design, conditions during testing, and difference in oat cultivars studied. Several studies also had small cohorts or significant patient withdrawals during studies. 4. This review aims to encourage clinical and in vitro studies to investigate the benefits of recommending oats in a gluten-free diet.