MICRONUTRIENTS AND PROSTATE CANCER RISK

Abstract

This thesis aimed to elucidate the associations between micronutrients and prostate cancer risk. In the Singapore Prostate Cancer Study, a hospital-based case-control study, higher serum concentrations of retinol, lutein, α-carotene, β-carotene, ubiquinone, α-tocopherol, δ-tocotrienol, γ-tocotrienol, α-tocotrienol were significantly and positively associated with prostate cancer risk; smoking status and alcohol consumption acted as effect modifiers. Retinol and α-tocotrienol contributed most to the group indices 'vitamin A and provitamin A carotenoids' and 'vitamin E’, which were positively associated with risk. In a meta-analysis, dietary and supplemental vitamin E intake were not associated with prostate cancer risk. Stratification by study design, sample size, study population and dose, did not change the findings. However, prostate cancer risk was significantly lower with supplemental vitamin E intake in European studies (RR = 0.81, 95% CI = 0.69–0.97). More mechanistic studies are required to clarify the involvement of Vitamin A and E in prostate cancer risk.