Objectives: Celiac disease (CD) may occur in genetically predisposed individuals exposed to gluten, but it is unclear whether the amount of gluten influences the risk of disease. We aimed at determining whether the amount of gluten intake at age 18 months predicted later risk of CD.
Methods: In an observational nationwide cohort study, the Norwegian Mother and Child Cohort Study (MoBa), we included 67,608 children born during 2000-2009 and followed up for a mean of 11.5 years (range 7.5-15.5) after exclusions for missing data. Information regarding CD diagnosis was obtained from the Norwegian Patient Register 2008-2016 and from parental questionnaires at child age 7 and 8 years. We estimated gluten intake at age 18 months from a prospectively collected parental questionnaire.
Results: CD was diagnosed in 738 children (1.1%, 62% girls). The mean estimated amount of gluten in the diet at 18 months was 8.8 g/d (SD 3.6). The adjusted relative risk of CD was 1.10 (95% confidence interval 1.03-1.18) per SD increase in daily gluten amount at age 18 months. Children in the upper quartile of gluten intake compared with the lower quartile had an increased risk of CD (adjusted relative risk 1.29, 95% confidence interval 1.06-1.58). The association with gluten amount was independent of the age at introduction of gluten. Gluten introduction ≥6 months was also an independent risk factor for CD.
Discussion: In this nationwide study, increased gluten intake at 18 months was associated with a modestly increased risk of CD later in childhood.