5 Questions About the Risk of Gluten Transfer With Kitchen Appliances

Gluten-free diet guides published by professional societies, hospitals, and advocacy organizations suggest using dedicated toasters to prevent cross-contact with gluten.

Findings of a new study conducted by Vanessa Weisbrod, BA, CA, a board-certified nutritionist and executive director of the Celiac Disease Program at Children’s National Hospital in Washington, DC, and colleagues indicated no significant gluten transfer when certain kitchen appliances and utensils were used with both gluten-free and gluten-containing foods.

Gastroenterology Consultant caught up with Vanessa Weisbrod about the research and current management challenges in pediatric celiac disease.

Gastroenterology Consultant: What do you think are the biggest challenges in the management of celiac disease?

Vanessa Weisbrod: The biggest challenge is knowing whether or not someone is actually following a gluten-free diet. The standard is to follow blood antibody levels, but there is no perfect test to know how compliant a patient is being with the diet, so we rely on questioning families, watching antibody levels go down, reports of how they are feeling, and reduction in symptoms. We are also starting to use gluten immunogenic peptide tests that allow us to measure gluten in urine and stool, but these tests are not perfect, because you have to retrieve the sample very close to the time of ingestion in order to measure the gluten. Another big challenge is balancing the risk of gluten exposure with harm from hypervigilance. Many of our patients suffer from anxiety, depression, and social isolation because they are constantly worried about exposure to gluten. We hope that this study is the first step towards getting really good data to help patients understand the true risks of exposure to gluten and become appropriately vigilant.

GASTRO CON: What prompted you to conduct the study?

VW: The Celiac Disease Program at Children’s National Hospital was assembling a panel of national experts from pediatric hospitals, education associations, advocacy groups, parents, and students to develop national guidelines for kids with celiac disease to safely attend school. As we started diving deeper into the project and looking at what other chronic disease groups had done for their kids at school, we immediately found that we were missing one very important element: data. We had plenty of well-intentioned ideas about how to prevent cross-contact with gluten in the kitchen and in the classroom, but none of it came with any data to support the interventions. So, we decided to conduct two studies, one looking at the risk of cross-contact with gluten in shared kitchens, and one looking at cross-contact with gluten in school supplies. Our second paper on cross-contact with gluten in school supplies like Play-Doh and paper mâché was just published in January 2020 in the Journal of Pediatric Gastroenterology.

GASTRO CON: Has gluten transfer between kitchen utensils and appliances been a significant problem in the past?

VW: This is the first time we have data showing the transfer. Historically, recommendations from hospitals, advocacy groups, and professional societies have been based on what is thought to be best rather than data showing if a transfer actually occurs. Our pilot data shows us that in some cases there is a big transfer (cooking gluten-free pasta in the same water and pot used for gluten-containing pasta). However, washing those same pots with either soap and water or water alone removed the gluten so new gluten-free pasta was cooked with no transfer of gluten. The scenario with knives also had gluten transfers, although very low levels. However, once again, washing removed the gluten to less than 20 ppm. The lesson to learn here is that washing seems to work to get rid of the gluten. Toasters are almost impossible to clean, so we wanted to see if in the absence of washing, was enough gluten transferred to make a difference. All of the samples tested from shared toasters fell below the 20 ppm threshold set by the US Food and Drug Administration, with most of them having undetectable gluten.

GASTRO CON: What surprised you the most about the findings?

VW: We were most surprised by the toaster findings. We have always assumed they were a source of serious contamination, yet they appear to be remarkably safe. We need to conduct larger studies before changing global practices, but we are encouraged that our patients and families may be able to travel to grandma’s house without bringing a second toaster along in their luggage.

GASTRO CON: How can the study findings be applied to clinical practice?

VW: The findings can help make patients more aware of the importance of applying caution by intelligently balancing the downsides of hypervigilance with the need to avoid obvious sources of gluten and gluten contamination. When we have more detailed data, these instructions will become more precise.

Reference:

Weisbrod VM, Silvester JA, Raber C, McMahon J, Coburn SS, Kerzner B. Preparation of gluten-free foods alongside gluten-containing food may not always be risky for celiac patients as diet guides suggest. Gastroenterology. 2020;157(1):273-275. doi:10.1053/j.gastro.2019.09.007.