Wheat intolerance and chronic gastrointestinal symptoms in an Australian population-based study: association between wheat sensitivity, celiac disease and functional gastrointestinal disorders

OBJECTIVES: Wheat avoidance in the absence of celiac disease (CD) is common but occurrence of concurrent functional gastrointestinal disorders (FGIDs) in this group is uncertain. The aims of this study were to determine the prevalence of self-reported wheat or gluten sensitivity and doctor diagnosed CD in an Australian population, define the associated gastrointestinal (GI) symptoms and FGIDs, and determine the relationship between self-reported wheat sensitivity, demographic and medical factors. Methods: A total of 3542 people randomly selected from the Australian population returned a mail survey which contained questions on wheat avoidance, GI symptoms, demographic, medical, and lifestyle factors. We defined self-reported wheat sensitivity as people who reported gastrointestinal symptoms on ingestion of wheat based foods, but did not suffer from celiac disease, inflammatory bowel disease or colorectal cancer. Functional dyspepsia (FD) and irritable bowel syndrome (IBS) were diagnosed by Rome III criteria. CD status was self-reported. Results: The prevalence of self-reported wheat sensitivity in this cohort was 14.9% (95% CI 13.7–16.2). The prevalence of CD was 1.2% (95%CI 0.8–1.6). Doctor diagnosed CD was significantly associated with a diagnosis of FD (OR 3.35, 95%CI 1.72–6.52) and IBS (OR 2.28, 95%CI 1.08–4.81). Those with self-reported wheat sensitivity were more likely to report multiple abdominal symptoms (of the 18 assessed) than those without (3.9 symptoms with self-reported wheat sensitivity vs. 1.6 without, p = 0.0001). In a multivariate analysis, self-reported wheat sensitivity was independently associated with IBS (OR 3.55, 95%CI 2.71–4.65) and FD (1.48, 95%CI 1.13–1.94). Conclusions: Self-reported wheat sensitivity is common, with a prevalence of 14.9% in this cohort. There is a strong association between both celiac disease and self-reported wheat sensitivity, and chronic gastrointestinal symptoms, as well as a diagnosis of FD and IBS.