H. Salovaara and P. Kanerva, Department of Food Technology, P.O. Box 66, FI-00014 University of Helsinki, Finland; K. Kaukinen, Coeliac Disease Study Group, Medical School, FI-33014 University of Tampere, Finland; T. Sontag-Strohm
The Science of Gluten-Free Foods and Beverages
Oats, belonging to tribe Aveneae, are phylogenetically different from the Triticeae cereals of wheat, rye, and barley. Oats also differ in their protein composition, and a vital difference in the amino acid sequence from the coeliac-toxic Triticeae cereals has been identified. Ever since the introduction of the gluten-free concept more than 50 years ago, there has been uncertainty and controversy about the status of oats. Today, results from more than 15 clinical studies published in the past 15 years have shown that considerable amounts (50 g or more) of oat flakes or oat flour can be safely consumed by most adults and children with coeliac disease, including those with the dermatitis herpetiformis form of the disease. In 2007, the U.S. Food and Drug Administration (FDA) put forward a definition for the term “gluten-free” and proposed that oats should not be classified as prohibited grains. The international standard for foods for persons intolerant to gluten, as formulated by the Codex Alimentarius, recognised in 2008 that oats can be tolerated by most people intolerant to gluten, although oats may not be tolerated by all of them. The EU regulation (2009) declared that oats contained in foodstuffs for people intolerant to gluten must be specially produced and the gluten content must not exceed the new limit of 20 mg/100 g. In spite of the evidence suggesting oats are safe, two areas of concern remain, namely the possible comingling (mixing, “contamination”) of oats with wheat, rye, or barley, and the existence of a possible subgroup among coeliac patients that develop mucosal inflammation and symptoms when eating oats. The comingling problem can be eliminated by suitable agronomic, logistical, and food processing practices. This problem, in particular with barley, might have been overestimated due to problems with the interpretation of results obtained with the newly introduced ELISA R5 method. The number of coeliac patients sensitive to oats is probably very low; so far, only a few oat-sensitive individuals have been reported, whereas there have been hundreds of coeliac patients participating in studies showing oats have no adverse effect. Most of the celiac patients in Finland use oat products, and the authorised labelling of products uses the wording, “contains oats and gluten-free ingredients.” In conclusion, recent evidence from clinical research and practice shows that oat products, in particular when made specifically for coeliac customers, cause no harm to most coeliac disease patients. With oat products included, there is more variation and nutritional value in the coeliac diet, so better compliance and an improved quality of life can be expected. The new regulatory limit, 20 mg/kg in oats, provides an analytical and technological challenge.