Investigating the effects of lycopene and green tea on the metabolome of men at risk of prostate cancer: The ProDiet randomised controlled trial. Issue 8 (7th December 2018)

• Record Type: Journal Article
• Authors: Beynon, Rhona A.; Richmond, Rebecca C.; Santos Ferreira, Diana L.; Ness, Andrew R.; May, Margaret; Smith, George Davey; Vincent, Emma E.; Adams, Charleen; Ala‐Korpela, Mika; Würtz, Peter; Soidinsalo, Sebastian; Metcalfe, Christopher; Donovan, Jenny L.; Lane, Athene J.; Martin, Richard M.
• Is Part Of: International journal of cancer. Volume 144:Issue 8(2019)
• Page Start: 1918
• Page End: 1928
• Publication Date: 2018-12-07
• Subjects: prostate cancer -- dietary intervention -- lycopene -- green tea -- Mendelian randomisation; Cancer -- Periodicals; Cancer -- Prevention -- Periodicals; 616.994
• DOI: 10.1002/ijc.31929
• Languages: English
• ISSNs: 0020-7136

Abstract

Abstract : Lycopene and green tea consumption have been observationally associated with reduced prostate cancer risk, but the underlying mechanisms have not been fully elucidated. We investigated the effect of factorial randomisation to a 6‐month lycopene and green tea dietary advice or supplementation intervention on 159 serum metabolite measures in 128 men with raised PSA levels (but prostate cancer‐free), analysed by intention‐to‐treat. The causal effects of metabolites modified by the intervention on prostate cancer risk were then assessed by Mendelian randomisation, using summary statistics from 44, 825 prostate cancer cases and 27, 904 controls. The systemic effects of lycopene and green tea supplementation on serum metabolic profile were comparable to the effects of the respective dietary advice interventions ( R 2 = 0.65 and 0.76 for lycopene and green tea respectively). Metabolites which were altered in response to lycopene supplementation were acetate [ β (standard deviation difference vs . placebo): 0.69; 95% CI = 0.24, 1.15; p = 0.003], valine ( β : −0.62; −1.03, −0.02; p = 0.004), pyruvate ( β : −0.56; −0.95, −0.16; p = 0.006) and docosahexaenoic acid ( β : −0.50; −085, −0.14; p = 0.006). Valine and diacylglycerol were lower in the lycopene dietary advice group (β: −0.65; −1.04, −0.26; p = 0.001 and β : −0.59; −1.01, −0.18; p = 0.006). A genetically instrumented SD increase in pyruvate increased the odds of prostate cancer by 1.29 (1.03, 1.62; p = 0.027). An intervention to increase lycopene intake altered the serum metabolome of men at risk of prostate cancer. Lycopene lowered levels of pyruvate, which our Mendelian randomisation analysis suggests may be causally related to reduced prostate cancer risk. Abstract : What's new? Prostate cancer incidence varies by geographic region, suggesting that environmental factors, such as diet, play a role. Here, the authors investigated how green tea and lycopene intake affects prostate cancer risk. They conducted a 6‐month intervention on men with raised PSA levels but no cancer, testing levels of 159 serum metabolites by NMR. Lycopene supplementation, they found, reduced levels of circulating pyruvate, and Mendelian randomisation analysis suggests pyruvate may boost PC risk. These results suggest a possible mechanism of action by which consuming dietary lycopene may reduce prostate cancer risk.