Study: One-third of "gluten-free" restaurant foods in the United States are not

MONDAY, Oct. 8, 2018 (HealthDay News) – If you're sensitive to gluten, be careful: a third of the "gluten-free" foods sold in American restaurants actually contain traces of this substance, according to new research.

The discovery will be of particular concern to the 1% of Americans with autoimmune disease called celiac disease. For them, even a tiny amount of gluten – a protein contained in wheat and other grains – can damage the intestinal lining.

"While awareness of celiac disease and the gluten-free diet has increased in recent years, restaurants have sought to offer selections consistent with these restrictions," said Dr. Benjamin Lebwohl, author of the study. . "But some institutions are doing better than others at preventing cross-contamination."

And some gluten-free foods were more risky than others. According to the study, for example, more than half of the pasta and pizza supposedly gluten-free contained gluten.

Why?

"The fact that gluten has been so often found in a pizza suggests that sharing an oven with a gluten-containing pizza is a favored framework for cross-contamination," explained Lebwohl, of the Celiac Disease Center's Columbia University. "Gluten-free pasta may be contaminated if prepared in a pot of water used to make pasta containing gluten."

Although the US Food and Drug Administration regulates packaged foods with gluten-free labeling, the federal government does not monitor gluten-free food claims in restaurants, Lebwohl said.

For this study, more than 800 researchers undertook to evaluate the true gluten content of the gluten-free dishes on the menus. Armed with portable gluten sensors, they tested gluten levels equal to or greater than 20 parts per million, the standard threshold for any claim related to the absence of gluten.

Based on more than 5,600 gluten tests over an 18-month period, investigators determined that 27% of gluten-free breakfasts were actually gluten-based. At dinner time, this figure reached 34%. The increase may reflect a steady rise in the risk of gluten contamination as the day progresses, the researchers said.

The concerns go beyond the celiac community alone.

"There are also people who do not suffer from celiac disease but who have symptoms triggered by gluten," said Lebwohl. People with this problem – sensitivity not related to celiac gluten – rely on gluten-free labeling and safe food preparation practices for the prevention of uncomfortable symptoms, he noted. These can include constipation, bloating and nausea.

"These findings underscore the need for food preparation education in restaurants and the need for guests to inquire about these precautions," said Lebwohl.

Dietitian Lona Sandon agreed. Gluten contamination in restaurants "has long been a concern for people with celiac disease," said Sandon, an associate professor of clinical nutrition at the Southwestern Medical Center at the University of Texas at Dallas. She was not involved in the study.

"Restaurant kitchens are simply not built to ensure the prevention of gluten contamination," said Sandon. A chef can easily put a gluten-free bread on a cutting board containing just a wheat bread while trying to quickly deliver food to the customer. Again, staff may simply not know what contains gluten and what does not, it added.

In the absence of federal control at the restaurant level, it is up to the person handling the gluten-free product to prevent it from becoming contaminated, Sandon said.

The study is to be presented Monday at a meeting of the American College of Gastroenterology in Philadelphia. Research presented at meetings is generally considered preliminary until it is published in a peer-reviewed medical journal.

More information

There is more information on gluten-free foods and celiac disease in the US Department of Health and Human Services.