Oral Presentation International Celiac Disease Symposium 2026

Quantifying Dietary Gluten Exposure from Shared Fryers: Implications for Nutritional Management and Health Outcomes in Celiac Disease   (139049)

Vanessa Weisbrod 1 , Meghan Donnelly 1 , Marisa Stahl 2 , Monique Germone 2 , Sadie Nagle 2 , Jackie Jossen 3 , Jessica Lebovits 3 , Maureen M Leonard 4 , Joanna Perl 5 , Marilyn G Geller 1 , Aaron Geller 1 , Luke Emerson-Mason 6 , Zhaoxing Pan 2 , Ritu Verma 7 , Edwin Liu 2
  1. Celiac Disease Foundation, Needham, MA, United States
  2. Children's Hospital Colorado, Aurora, CO, United States
  3. Columbia University Medical Center, New York, NY, United States
  4. Mass General Brigham for Children, Boston, MA, United States
  5. Vanderbilt Health, Nashville, TN, United States
  6. Bia Diagnostics, Colchester, VT, United States
  7. University of Chicago, Chicago, IL, United States

Background: Shared fryers are widely considered high-risk for gluten cross-contact, leading many individuals with celiac disease (CeD) to avoid foods such as french fries and tortilla chips. However, real-world data evaluating gluten contamination in shared fryers are limited. Because mucosal injury in CeD is dose-dependent, understanding gluten exposure from common dining practices is critical for dietary counseling.

Objective: To quantify gluten concentrations in naturally gluten-free (GF) foods prepared in shared fryers across food service settings and assess the impact of fryer practices and restaurant type.

Methods: In this cross-sectional study, 98 samples of french fries (n=55) and tortilla chips (n=43) were collected from fast food, fast casual, and casual dining establishments across multiple U.S. states. All items were naturally GF prior to frying and cooked in fryers shared with gluten-containing foods. Gluten content was measured using ELISA. Variables included sample type, restaurant category, location, and fryer oil change frequency. Per FDA standards, <20 ppm was considered GF; <5 ppm was below detection.

Results: Six samples (6.1%) exceeded 20 ppm. Most samples (84/98, 85.7%) were <5 ppm. All tortilla chips tested <5 ppm. Fast food and fast casual samples consistently measured <5 ppm, while casual dining showed greater variability, including all >20 ppm samples. All foods from establishments reporting daily oil changes measured <20 ppm, whereas weekly oil changes were associated with higher and more variable gluten levels.

Conclusions: Shared fryers were not uniformly associated with clinically meaningful gluten cross-contact. Gluten levels varied by setting and fryer practices, with consistently low or undetectable levels observed in establishments with daily oil replacement. These findings support a risk-stratified approach to nutritional management in CeD, in which gluten exposure is evaluated based on dose, frequency, and cumulative intake rather than binary avoidance, with implications for optimizing long-term health outcomes and quality of life.