Gluten was detected in more than half of pizza and pasta dishes that restaurants labeled “gluten-free,” showed a new study.
Benjamin Lebwohl, M.D., MS, Celiac Disease Center at NY-Presbyterian Hospital and assistant professor of medicine and epidemiology at Columbia Mailman School of Public Health, used data uploaded by users of a portable sensor designed to test foods. The device manufacturer supplied 5,624 food tests by 804 users over 18 months. The findings revealed that 32% of tests had gluten in dishes that were supposedly gluten-free. Gluten-free pasta samples were positive in 51% of tests and gluten-free pizza in 53%.
To be labeled gluten-free in the U.S., a product must contain less than 20 parts per million. “The device can detect levels as low as 5–10 ppm, which most do not consider clinically significant, so a ‘gluten found’ result does not necessarily mean ‘unsafe for celiac disease.’ The device also does not detect certain forms of gluten, such as fermented gluten. So, both false positives and false negatives will affect this estimate,” noted Lebwohl. He also suspects that gluten-free foods are inadvertently contaminated, and that the solution may be better education for food preparers.