Vegetable and fruit intake and the risk of bladder cancer: Japan Public Health Center-based prospective study

Background Vegetable and fruit consumption may have a protective effect against several types of cancer. However, evidence suggesting that increased intake of vegetables and fruits, their subtypes, or the antioxidant nutrients they contain in abundance decreases the risk of bladder cancer is limited. Methods This study included 80,952 participants from the Japan Public Health Center-based Prospective Study, who responded to a food frequency questionnaire in a 5-year follow-up survey in 1995-1998 and were followed up until December 2015 to investigate the associations between intake of vegetables and fruits, their subtypes, or the antioxidant nutrients and bladder cancer risk using Cox proportional hazards regression models. Results Within 1,287,514 person-years of follow-up, 401 bladder cancer cases (307 men and 94 women) were diagnosed. No association was found between intake of total vegetable and fruit, total vegetable, total fruit, subtypes of vegetables and fruits, or antioxidant nutrients and bladder cancer risk in both men and women, even in the analyses conducted among men stratified by smoking status. Conclusions In this population, the consumption of vegetables and fruits was not associated with the risk of bladder cancer.