(Reuters Health) – For people with celiac disease, even small amounts of gluten in food can cause problems, and restaurants can be the hardest places to avoid hidden protein, suggests a US study.
More than half of gluten-free pizzas and pasta dishes tested in restaurants were positive for the presence of gluten, and overall about a third of foods believed to be gluten-free contained gluten, researchers in the American report. Journal of Gastroenterology.
“The long suspected problem of gluten contamination in restaurant foods that has been reported by patients probably has some truth behind it,” said lead author of the study, Dr. Benjamin Lebwohl, director of the clinical research at the Celiac Center of the New York Presbyterian Hospital and Columbia University Medical Center in New York.
“We don’t know how common this is. But our results suggest that pizza, pasta, and foods served at dinner time are more likely to have this problem. “
Lebwohl often heard patients say they suspected they consumed gluten in restaurants, even though the foods they ate were labeled gluten-free.
When he learned that the maker of the portable Nima Gluten Sensor had a stash of data submitted by restaurant patrons who were using the device to test foods they suspected, Lebwohl asked if he could use the information in a study.
The company provided what it had: 5,624 food tests performed by 804 users over an 18-month period. When the researchers analyzed the data, they found that 32% of tests revealed gluten contamination in dishes believed to be gluten-free.
Gluten-free pasta samples were positive for protein in 50.8% of tests, while gluten-free pizzas were found to contain gluten in 53.2% of tests. Gluten was detected in 27.2% of breakfasts, 29% of lunches and 34% of dinners.
Lebwohl admits that there are a lot of limitations to the dataset. “People tested what they wanted to test,” he said. “And the users chose which results to upload to the business. Perhaps they downloaded the results that surprised them the most. So our results do not mean that 32 percent of food is unsafe. “
In addition, says Lebwohl, the Nima is very sensitive. To be labeled gluten-free in the United States, a product must contain less than 20 parts per million (ppm). But the device can detect levels as low as 5-10 ppm, which “most people wouldn’t consider clinically significant.” Thus, it is possible that a food contains less than 20 ppm and still indicates the presence of gluten.
The Nima gluten detector, which retails for around $ 229 and uses disposable $ 6 test strip capsules, displays a wheat symbol when it detects gluten and a smiley face when it does not, note the authors. He can upload the results to the company via a smartphone application.
Lebwohl suspects that gluten-free foods are inadvertently contaminated. “If a gluten-free pizza is put in an oven with a pizza containing gluten, aerosol particles could come in contact with the gluten-free pizza,” he said. “And it’s possible that cooking gluten-free pasta in a pot of water that had just been used for pasta containing gluten could lead to contamination.”
The solution, Lebwhol said, could be better education for food preparers.
About 1% of Americans have celiac disease, Lebwohl said. The amount of gluten needed to cause intestinal damage in these patients is minimal, he added. “It would be barely visible, like tiny crumbs of bread,” he explained.
While data limitations mean that it’s not possible to determine what percentage of restaurant foods labeled gluten-free actually contain protein, “it’s interesting to know that so many foods labeled as gluten-free don’t. not, ”said Therezia Alchoufete, a clinical dietitian at the Digestive Disorders Center at the University of Pittsburgh Medical Center.
“It’s definitely a consideration for anyone with celiac disease who tries to eat outside of the home. At home, they know they are preparing foods that are free from any elements containing gluten. The problem goes beyond gluten, Alchoufete said. “This could apply to anyone sensitive to a certain ingredient.”
THE SOURCE: bit.ly/2JZT3zk American Journal of Gastroenterology, online March 26, 2019.