How can you trust gluten-free labels?

Additionally, any unavoidable presence of gluten in the food must be less than 20 ppm. Foods that meet this definition can be labeled as gluten-free but the use of a gluten-free label is voluntary. These regulations apply to foods that are imported into the US as well as domestically produced foods [1]. The threshold level for gluten is set at 20 ppm for several reasons. Firstly, tests that claim to be able to detect gluten at levels below 20 ppm are not scientifically valid. Secondly, due to the difficulties in removing all gluten and the risk of cross-contact in growing, harvesting, or processing crops, traces of gluten are unavoidable. Thirdly, evidence shows that people with celiac disease may not experience symptoms when exposed to trace amounts of gluten [1]. The FDA regulations allow manufacturers to include the logo of a gluten-free certification program to help consumers choose gluten-free foods, provided the statement is truthful and not misleading; however, they do not endorse this certification [1].

How gluten content is monitored

To test for and quantify the gluten content of foods, antibody-test systems, such as enzyme-linked immunosorbent assays (ELISA), are often used [2]. The FDA regulations state that food manufacturers may select the most appropriate test methods for analyzing their products for gluten themselves. However, the methods chosen should be scientifically validated for detecting gluten and the results obtained must be reliable and consistent [1].

As of 2018, the FDA has identified two ELISA-based methods that will be used to determine compliance with the regulations. However, the FDA has acknowledged that ELISA methods do not adequately detect gluten in fermented and hydrolyzed foods (e.g., beers, soy sauce, etc.) [1]. This is because processing food in this way can alter certain gluten constituents (i.e., prolamin and glutelin) to generate protein fragments that cannot be detected by many gluten assays.2 For more comprehensive detection of gluten in processed foods, antibodies directed against additional celiac disease-active epitopes of gluten are necessary [2].

Food labeling – allergy advisory statements

All packaged foods in the US should comply with the Food Allergen Labeling and Consumer Protection Act of 2004, that requires all food labels to list ingredients that may cause allergic reactions [3]. Statements such as “may contain…”, “made in a shared facility with…”, “made on shared equipment with…” are voluntary and not defined regulations [3]. Allergen advisory statements can be used in addition to gluten-free labeling if a product meets the standard of less than 20 ppm gluten. However, this is a source of confusion for consumers with celiac disease or other gluten-related disorders many of whom would not buy or eat foods that have these allergy advisory statements [4].

Safety recommendations

Gluten-free labeling is voluntary, so some foods that are not labeled gluten-free may still be suitable for people with celiac disease or other related gluten disorders [1]. It is important for consumers to check food labels for gluten containing ingredients and to check allergen advisory statements. Consumers should be vigilant for products labeled as gluten-free when they contain ingredients that are prohibited by the FDA from being contained in any product labeled as “gluten-free”. This includes barley malt/barley malt extract/malted vinegar (e.g., in beer, potato chips), wheat/wheat flour (e.g., in soy sauce, baking mixes), spelt or couscous. Such errors – termed “facial misbranding” – should be reported to the FDA [5].

Allergen advisory statements are also voluntary; they are largely unregulated and may confuse consumers (e.g., if an allergy statement for wheat appears on a product that is labeled as gluten-free). This is lawful, as long as the product meets the gluten-free standards. Research shows that allergy advisory statements are not reliable predictors of gluten contamination [6], therefore, people with celiac disease or other gluten-related disorders should not rely only on allergy advisory statements to determine what is safe to eat. Instead, they should contact the manufacturers to ask questions about their manufacturing processes, obtain further information from consumer sites such as the Gluten Free Watchdog [7], or purchase products from trusted gluten-free manufacturers [5]. People with celiac disease should also check that oats are suitable for them. If the product does not state that it is prepared using purity protocol oats, then the consumer should either check with the manufacturer or confirm the product/manufacturer is included on the list of oats on the Gluten Free Watchdog website [7].