Gluten Intake and All-Cause and Cause-Specific Mortality: Prospective Findings from the UK Biobank

ABSTRACT Background Gluten has been linked to adverse effects on metabolic and vascular health. Objectives The present study determines the association between dietary gluten intake and all-cause (primary objective), as well as cause-specific, mortality in people without celiac disease. Methods Gluten intake was estimated in 159,265 participants of the UK Biobank which is a large multicenter, prospective cohort study initiated in 2006. Cox proportional hazard regression models were used and HRs were determined for all-cause and cause-specific mortality. All models were adjusted for confounders and multiple testing. Results Median (IQR) age was 57 (49–62) y with 52.1% of participants being female. Gluten intake was 8.5 (5.1–12.4) g/d with significantly higher consumption in males [10.0 (6.3–14.1) g/d] than in females [7.2 (4.6–10.7) g/d] (P < 0.0001). During a median follow-up of 11.1 (10.6–11.9) y and 1.8 million person-years, 6259 deaths occurred. Gluten intake was not significantly associated with all-cause mortality after adjusting for confounders (HR: 1.00; 95% CI: 1.00, 1.01; P = 0.59). Dietary gluten was not significantly associated with cancer (HR: 1.00; 95% CI: 1.00, 1.01; raw P = 0.24) or noncancer (HR: 1.00; 95% CI: 0.99, 1.01; raw P = 0.56) mortality. However, gluten intake was positively associated with ischemic heart disease mortality (HR: 1.02; 95% CI: 1.01, 1.04; raw P = 0.003, Holm-adjusted P = 0.04). Conclusions Gluten intake is not significantly associated with all-cause and cancer mortality in adults without celiac disease. The findings support the hypothesis that limiting gluten intake is unlikely to provide significant overall survival benefits on a population level. The positive association between gluten intake and ischemic heart disease mortality requires further study.