Beynon RA, et al. - In order to elucidate the mechanism underlying the protective effect of lycopene and green tea consumption against prostate cancer risk, researchers analyzed 159 serum metabolite measures in 128 men with raised prostate-specific antigen levels (but prostate cancer-free) randomized to a 6-month lycopene and green tea dietary advice or supplementation intervention. Mendelian randomization was used to assess the causal effects of metabolites modified by the intervention on prostate cancer risk, using summary statistics from 44,825 prostate cancer cases and 27,904 controls. Outcomes revealed altered serum metabolome in relation to an intervention to increase lycopene intake among men at risk of prostate cancer. Pyruvate levels lowered in correlation with lycopene intake, which the Mendelian randomization analysis suggests may be causally related to reduced prostate cancer risk.