Diet Quality and Risk of Bladder Cancer in the Multiethnic Cohort Study

This study analyzed the overall quality of the diet using predefined indices, including the Healthy Eating Index-2015 (HEI-2015), the Alternative Healthy Eating Index-2010 (AHEI-2010), the alternate Mediterranean Diet (aMED) score, the Dietary Approaches to Stop Hypertension (DASH) score, and the Dietary Inflammatory Index (DII (R)), to explore their association with the risk of bladder cancer in the Multiethnic Cohort Study. Data were taken from 186,979 African American, Japanese American, Latino, Native Hawaiian, and non-Hispanic White participants aged 45-75 years, with 1152 incident cases of invasive bladder cancer during a mean follow-up period of 19.2 +/- 6.6 years. Cox models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) with comprehensive adjustment for smoking. Comparing the highest vs. lowest diet quality score quintile, HRs (95% CIs) in men was 1.08 (0.86-1.36) for HEI-2015, 1.05 (0.84-1.30) for AHEI-2010, 1.01 (0.80-1.27) for aMED, 1.13 (0.90-1.41) for DASH, and 0.96 (0.76-1.21) for DII (R), whereas the corresponding HRs for women were 0.75 (0.53-1.07), 0.64 (0.45-0.92), 0.60 (0.40-0.88), 0.66 (0.46-0.95), and 0.63 (0.43-0.90) with all p values for trend <0.05. The inverse association found in women did not vary by smoking status or race and ethnicity. Our findings suggest that adopting high-quality diets may reduce the risk of invasive bladder cancer among women in a multiethnic population.