Fruits and vegetables in relation to prostate cancer in Japanese men: the Japan Public Health Center-Based Prospective Study.

Although dietary risk factors may differ between localized and advanced prostate cancer, data on associations between the consumption of fruits and vegetables and risk of localized and advanced cancers are limited. We examined associations between fruit and vegetable consumption and risk of prostate cancer in a Japanese population. During 1995-1998, a validated food frequency questionnaire was administered to 43,475 men aged 45-74 yr. During 321,061 person-years of follow-up until the end of 2004, 339 cases of prostate cancer were identified. Consumption of fruits or total vegetables was not associated with a decreased risk of total prostate cancer, with corresponding multivariate hazard ratios of the highest vs. lowest quartiles of 1.09 (95% CI = 0.77-1.53; trend P = 0.39) for fruits and 1.33 (95% CI = 0.93-1.91; trend P = 0.52) for total vegetables. Also, no association was observed for intake of either fruits or vegetables (total or any subtype) with localized or advanced prostate cancer. This prospective cohort study suggests that consumption of fruits or vegetables may not be associated with the risk of either localized or advanced prostate cancer in Japanese men. However, the possibility of confounding by detection bias on the risk of localized cancer could not be totally ruled out.