Dietary total antioxidant capacity alleviates inflammatory bowel disease-related surgery, gastrointestinal cancer, and mortality risks among middle-aged and older individuals

OBJECTIVES: This study aimed to investigate the association between dietary total antioxidant capacity (TAC) and the risks of clinical outcomes, including surgery, gastrointestinal cancer, and mortality, among middle-aged and older individuals with IBD. DESIGN: Nationwide prospective cohort study. SETTING AND PARTICIPANTS: We included middle-aged and older participants with IBD when recruited in the UK Biobank. MEASUREMENTS: Dietary TAC was calculated by the oxygen radical absorbance capacity from the food by repeated dietary recalls. The outcomes representing IBD prognosis include IBD-related surgery, gastrointestinal cancer, and death events. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using Cox proportional hazard models. Polymorphism of antioxidant-related enzymes genes was ascertained via genotype data. RESULTS: With a median follow-up period of 10.9 years, we documented 174 cases of IBD-related surgery, 52 gastrointestinal cancer, and 189 death events among 2487 IBD participants. Compared to the lowest quartile of dietary TAC, participants in the highest quartile presented lower risks of IBD-related surgery (HR 0.53; 95% CI 0.34-0.84; P-trend = 0.005) and all-cause mortality (HR 0.61; 95% CI 0.39-0.96; P-trend = 0.014). Compared to the lowest decile, participants in the higher deciles of dietary TAC had a lower risk of gastrointestinal cancer (HR 0.39; 95% CI 0.19-0.83; P = 0.014). We also found genetic variants in catalase gene CAT and antioxidant transporter gene SLC2A14 modified the association between dietary TAC and IBD prognosis. CONCLUSIONS: Higher dietary TAC was associated with better prognosis of middle-aged and older individuals with IBD, including lower risk of related surgery, gastrointestinal cancer, and all-cause mortality, suggesting the importance of adherence to high-TAC diet in IBD management.