Pasta and pizzas are the foods most likely to contain some traces of gluten, which can cause a life-threatening reaction in the 1 per cent of people who are celiacs, and unpleasant side effects in the gluten-intolerant, estimated to be around half the adult population.
Around half the gluten-free pasta dishes and pizzas actually contained gluten, researchers from Columbia University discovered when 800 of their investigators carried out spot checks on 5,600 gluten-free options in restaurants across the US.
Around 27 per cent of breakfast meals contained traces of gluten, and this rose to 34 per cent of the meals served for dinner. Half the pasta dishes and pizzas contained gluten, measured as 20 parts per million, considered the cut-off point for gluten-free claims.
The major problem was cross-contamination in the kitchen from food containing gluten when meals are prepared, said lead investigator Benjamin Lebwohl. "The fact that gluten was so often found in pizza suggests that sharing an oven with gluten-containing pizza is a prime setting for cross-contamination. Gluten-free pasta can be contaminated if prepared in a pot of water that was used to prepare gluten-containing pasta."
(Source: Proceedings of the American College of Gastroenterology annual meeting, October 15th, 2018)