Dietary Patterns and Prostate Cancer Risk in the Multiethnic Cohort Study

Background:Healthy dietary patterns have been linked to reduced cancer risk, but evidence for prostate cancer (PCa) remains inconsistent, especially across diverse populations. Methods:In the Multiethnic Cohort Study, we examined the associations between 11 diet scores and PCa risk among 79,930 men (White, African American, Japanese American, Latino, or Native Hawaiian). Hazard ratios (HRs) and 95% confidence intervals (CIs) per one standard deviation (SD) increase in each score were estimated from Cox proportional hazards models for total PCa and by grade, stage, and aggressiveness. Analyses were conducted in the overall population and within racial/ethnic groups. A significance threshold of p<0.003 was used to adjust for multiple testing. Results:Over a mean follow-up of 18.8 years, 9,759 PCa cases were identified. No significant associations were observed in the hypothesized direction between dietary scores and PCa risk in the overall population. However, among African Americans, higher Dietary Approaches to Stop Hypertension (DASH) scores were suggestively associated with a 14% lower risk of advanced PCa (95% CI: 0.77-0.98, p=0.02). Among Japanese Americans, higher Empirical Dietary Index for Insulin Resistance (EDIR) scores were linked to an increased risk of low-grade (HR=1.09, 95% CI: 1.02-1.17, p=0.01) and non-aggressive PCa (HR=1.10, 95% CI: 1.02-1.19, p=0.02). Conclusions:Although no strong associations were found overall, our findings suggested that specific dietary patterns may influence PCa risk differently by race/ethnicity and tumor subtype, warranting further investigation in large and diverse populations. Impact:These findings highlight the need for future studies to explore disease-specific and culturally informed dietary patterns that may inform PCa prevention across diverse populations.