Confirmation of gluten-free status of wheatgrass

Authors: Adrianos, Sherry; MATTIONI, BRUNA - Universidade Federal De Santa Catarina (UFSC); Tilley, Michael - Mike

Submitted to: Quality Assurance and Safety of Crops & Foods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/13/2016
Publication Date: 1/2/2017
Citation: Adrianos, S.L., Mattioni, B., Tilley, M. 2017. Confirmation of gluten-free status of wheatgrass. Quality Assurance and Safety of Crops & Foods. 09(1):123-128.

Interpretive Summary: Traditional medicine practices have long valued dietary supplementation with herbal or nutraceutical compounds. The leaves of common wheat (Triticum aestivum L.) are a plentiful and easy source for such supplements. Wheat grass is consumed as a juice of freshly harvested leaves or reconstituted from powder leaves. Powdered material is additionally consumed in capsule format. To ensure freshness and purity many consumers choose to grow and process plants at home. Although limited literature exists regarding efficacy of wheat grass in the medical literature, clinical studies have shown positive effects alleviating symptoms of ulcerative colitis and severe anemia resulting from chemotherapy. As a wheat product, persons on a gluten-free diet such as celiac disease or other gluten related disorders, were curious as to the gluten status of wheat grass. A commercial product and freshly grown wheat grass were tested using the gluten specific enzyme-linked immunosorbant assays (ELISA). Samples that were purposefully contaminated with known amounts of gluten proteins (spiked samples) were first tested to measure the ability to recover a quantity of the spiked protein. Spiking studies revealed that the majority of spiked material was recovered following extraction. ELISA data confirmed wheat leaves are devoid of gluten proteins as measured by specific antibody binding. Therefore, wheat grass contains no gluten and is safe for consumption by patients suffering from celiac disease or other gluten related disorders.

Technical Abstract: Celiac Disease (CD) and other gluten related disorders causes both malabsorption of nutrients and an abnormal immune reaction to gluten, the only effective therapy is a gluten-free diet. Codex Alimentarius sets the threshold level at 20 mg/kg gluten for gluten-free foods and this threshold has been adopted by many regulatory agencies such as the European Commission and the US Food and Drug Administration. Consumption of wheat grass extract has been reported to alleviate symptoms of ulcerative colitis and anemia which are often symptoms of CD. This investigation utilized the R5 and G12 sandwich ELISA assays to examine the potential gluten content of commercial and home grown wheat grass. Samples were spiked with commercial gliadin to assess recovery rates. Acceptable recovery rates ranging from 91 to 133% from gluten spiked samples were found. In all preparations the gluten content of wheat grass leaf tissue was lower than the limit of detection and limit of quantification for both ELISAs. According to results presented here wheat grass contains no gluten and is an appropriate dietary supplement while maintaining a gluten-free diet.