Prevalence of Gluten Contamination in Certified and Non-Certified Foods Labelled “Gluten-Free”

Abstract

Abstract Objectives Gluten is a common protein found in wheat, rye, and barely, and can sometimes be found in products that do not contain these grains. Gluten contamination in naturally gluten-free foods, products processed to remove gluten, and foods made with non-gluten derivatives is of concern for those suffering from an intolerance to gluten, such as Celiac disease. For these individuals, knowing whether or not food products advertised as “gluten-free” are truly so is necessary for their health and safety. The current study was designed to determine the reliability of “gluten-free” food labels in the consumer marketplace. Methods Samples of “gluten-free” foods were collected from a variety of locations, including grocery stores, health-food stores, and other non-grocery retailers. A total of 243 samples were analyzed using a Nima Gluten Sensor (antibody-based colorimetric assay) to determine if gluten content was < 20 ppm, the maximum allowed by US law for a product labeled “gluten-free”. Results Of the samples tested, 98 were certified as “gluten-free” (<10 ppm) by the Gluten-Free Certification Organization (GFCO); only 13 of these (13.3% of samples) were found to exceed 20 ppm of gluten. By comparison, 145 samples were labeled “gluten-free” on the packaging but did not contain GFCO or other recognized certification; of these, 42 (29.0%) were found to actually contain more gluten than allowed by law. Samples obtained from grocery stores (n = 161) and health-food stores (n = 29) had relatively few positive results (14.3% and 13.8% respectively), whereas samples obtained from stores whose primary function is not to sell food (n = 53) were much more likely to exceed the federal limit on gluten (43.4% of samples tested). Conclusions While results reveal that “certified gluten-free” products (GFCO or other organizations) should be more trusted by consumers in their claim of being “gluten-free”, contamination still poses some risk to those who are intolerant of gluten, and that risk is increased when certification is absent. Funding Sources Funding for this study came from the Robert M. Geist Endowed Chair in the Biological Sciences at Capital University.