About a third of gluten-free foods tested positive for the presence of gluten

A study by Benjamin Lebwohl, MD, MS, Center for Celiac Disease at the NY-Presbyterian Hospital and Assistant Professor of Celiac Disease is a problem for people with celiac disease. Medicine and Epidemiology at the Columbia Mailman School. More than half of the gluten-free pizzas and pastas in restaurants have been tested positive for the presence of gluten; about one-third of the supposedly gluten-free foods contained detectable gluten. The results are published in the American Journal of Gastroenterology.

"Patients have long suspected that gluten contamination in restaurant foods is a common occurrence, and these results corroborate this fact," said Lebwohl. "Our results suggest that pizzas, pastas and foods served at dinner were more likely to have a problem."

Lebwohl used data downloaded by users of the portable Nima Gluten Sensor device, which restaurant customers use to test food. The manufacturer provided 5,624 food tests conducted by 804 users over a period of 18 months. Research found that 32% of the tests revealed the presence of detectable gluten in dishes that were supposed to be gluten-free.

Gluten-free pasta samples were positive in 51% of the tests; Gluten-free pizzas contain 53% gluten. Gluten was detected in 27% of breakfasts, 29% of lunches and 34% of dinners.

Data is limited, notes Lebwohl. "Users may have downloaded the results that surprised them the most." In addition, the device is very sensitive. To be labeled gluten-free in the United States, a product must contain less than 20 parts per million. "The device can detect concentrations as low as 5 to 10 ppm, which most do not consider to be clinically significant. Therefore, a" gluten discovery "result does not necessarily mean" dangerous to the disease " The device also does not detect certain forms of gluten, such as fermented gluten, so false positives and false negatives will affect this estimate. "

Lebwohl suspects gluten-free foods to be inadvertently contaminated and "the solution could be a better education of food preparers".