A double-blind, placebo-controlled, gluten challenge has been proposed to confirm a diagnosis of nonceliac gluten sensitivity in patients without celiac disease who respond to a gluten-free diet.
To determine the accuracy of this approach, Drs Javier Molina-Infante and Antonio Carroccio from Spain analyzed data from 10 double-blind, placebo-controlled, gluten-challenge trials, comprizing 1312 adults.
The studies varied in the duration of the challenge, daily doses for the gluten challenge, and composition of the placebo.
|Only 16% of nonceliac gluten sensitivity patients showed gluten-specific symptoms|
|Clinical Gastroenterology & Hepatology|
The team found that most of the studies found gluten challenge to significantly increase symptom scores compared with placebo.
However, only 16% of nonceliac gluten sensitivity patients showed gluten-specific symptoms.
Furthermore, 40% of these subjects had a nocebo response.
Dr Molina-Infante's team comments, "These findings reveal heterogeneity and potential methodology flaws among studies of gluten challenge, cast doubt on gluten as the culprit food component in most patients with presumptive nonceliac gluten sensitivity, and highlight the importance of the nocebo effect in these types of studies."