An official website of the United States government.
<p>The researchers carried out a systematic review of all the scientific studies published between 1966 and March 2006 that had examined the relationship between the amount of gluten ingested or the concentrations of gluten in food products, and the development of symptoms or gut mucosal abnormalities in coeliac patients. Data were identified using pre-defined literature searching databases and reference lists of retrieved articles. Data from articles was extracted and various statistical analyses applied to see if it was possible to determine a statistically robust threshold level of gluten that coeliacs can tolerate.</p>
<p>Background: Coeliac disease is a life-long autoimmune disease caused by intolerance to gluten, a protein found predominantly in wheat, barley and rye cereals. Consumption of gluten causes damage to the gut lining, resulting in a wide range of symptoms such as bloating, diarrhoea, and nausea, as well as longer term health consequences if the disease is not managed. Management involves a strict gluten-free diet.</p>
<p>There has been much scientific uncertainty about what residual level of gluten in the diet is safe for those with coeliac disease, and there is currently no European or UK legislation defining "gluten-free". A draft Codex Standard developed in 1983, proposed a limit of 200 mg/kg of gluten in foods made from gluten-containing cereals that have been treated to reduce their gluten content and 20mg/kg for naturally gluten-free foods, and more recently there has been a proposal to reduce these thresholds to 100mg/kg for the former category and 20mg/kg for the latter. But this Standard had not been formally adopted (see below for an update on the situation with the Codex Standard) and there remains scientific uncertainty about safe thresholds of gluten for coeliacs.</p>
<p>This study was commissioned to evaluate published scientific articles that had investigated safe threshold amounts of gluten in foods in order to determine if it was possible to propose a clinical threshold dose of gluten or a threshold concentration of gluten in food products that would be tolerated by all people with coeliac disease.</p>