Detection of Gluten in Duplicate Portions to Determine Gluten Intake of Celiac Disease Patients on A Gluten Free Diet

This study determined the gluten content of foods and meals consumed by celiac disease (CD) patients who adhere to a gluten free diet, and to estimate the total daily intake of gluten of these patients. CD patients fulfilling defined inclusion criteria were preselected and approached for participation in the study. Duplicate portions (DP) of foods and mixed dishes were collected from the CD patients for evaluating complete daily food intake during two individual days. Also, for these days written food records were completed by the participants. From each DP a laboratory sample was prepared, analysed for its gluten concentration and total daily gluten intake was calculated. Individual's total daily intakes of energy and macronutrients were calculated using the Dutch food composition database.In total 27 CD patients participated, 7 males and 20 females, aged between 21 and 64 years. In 32 (6%) of in total 499 food samples collected, more than 3 mg/kg gluten was present. In four of these 32 samples, the gluten concentration was above the European legal limit of 20 mg/kg and 3 of the 4 samples had a gluten-free label.The maximal gluten intake was 3.3 mg gluten per day. The gluten tolerance for sensitive CD patients (> 0.75 mg per day) was exceeded on at least 6 out of 54 study days. To also protect these sensitive CD patients, legal thresholds should be re-evaluated and the detection limit of analytical methods for gluten analysis lowered.