There’s a moment in the new Netflix documentary series Rotten when celebrity chef and restaurateur Ming Tsai says directly to the camera “If you don’t know what’s in your food, get out of the business—today.” He is addressing restaurant owners and managers who don’t know what allergens are in the food they serve or otherwise fail to implement proper controls to prevent cross-contamination. The entire episode of “The Peanut Problem” revolves around food allergies and their sometimes fatal consequences with a particular focus on food service establishments, and Tsai’s admonishment feels like the climax of the show. Indeed, surveys show that there is a lack of specific food allergen training in restaurants. This lack of training can be due to a variety of reasons, including high turnover rates among food handlers, a language barrier, or a perception that food allergies simply do not have a substantial effect on business.
This lack of training also poses a problem in the context of celiac disease. Celiac disease is an intestinal disorder characterized by an intolerance to gluten, which is a protein found most notably in wheat, but is also present in other cereal grains in small amounts. Select foods that contain gluten are shown in Figure 1.
Celiac disease affects approximately 1% of the population worldwide), and the only known effective treatment is strict avoidance of any dietary gluten. There is also a related disorder known as non-celiac gluten sensitivity, which triggers an immune response when gluten-containing foods are consumed. This type of sensitivity may affect as much as 6% of the U.S. population.
In the U.S., the Food and Drug Administration (FDA) mandates that all consumer packaged food be labeled with their allergen content, but this does not extend to food served at restaurants. When eating out, individuals with celiac disease or other forms of sensitivity to allergens must communicate their dietary restrictions and rely on food handlers’ knowledge and expertise in controlling food allergens such as gluten to avoid exposure.
Gluten (cross-)contamination among food products that do not typically contain gluten or that are advertised as gluten free remains relatively common. However, most of the data on this topic to date comes from packaged retail goods, not restaurants. The data available for these types of establishments are usually limited to a single city such as Brasilia or Melbourne, because the restaurants have to be close enough to the investigators or the university to ensure samples can be obtained and brought back to the lab for analysis. These types of studies also show some level of gluten contamination in meals advertised as “gluten-free.” The study under review is the first study to examine gluten contamination of supposed gluten-free foods in restaurants throughout the U.S. using crowdsourced data.
Dining out can pose serious risks and challenges to people with celiac disease. The study under review utilizes crowdsourced data to estimate the prevalence of gluten contamination of supposed gluten-free foods in restaurants throughout the U.S.