Investigating the effects of lycopene and green tea on the metabolome of men at risk of prostate cancer: The ProDiet randomised controlled trial.

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 (R2 = 0.65 and 0.76 for lycopene and green tea respectively). Metabolites which were altered in response to lycopene supplementation were acetate [ß (standard deviation difference vs. placebo): 0.69; 95% CI = 0.24, 1.15; p = 0.003], valine (ß: -0.62; -1.03, -0.02; p = 0.004), pyruvate (ß: -0.56; -0.95, -0.16; p = 0.006) and docosahexaenoic acid (ß: -0.50; -085, -0.14; p = 0.006). Valine and diacylglycerol were lower in the lycopene dietary advice group (ß: -0.65; -1.04, -0.26; p = 0.001 and ß: -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.

Inverse relationship between alcohol consumption and active Helicobacter pylori infection: the Bristol Helicobacter project.

OBJECTIVE: The aim of this study was to examine whether smoking or consumption of alcohol or coffee is associated with active Helicobacter pylori (H. pylori) infection. METHODS: This was a cross-sectional population study conducted as part of a randomized controlled trial of H. pylori infection eradication in southwest England. A total of 10,537 subjects, recruited from seven general practices, underwent 13C-urea breath testing for active infection with H. pylori and provided data on smoking, usual weekly consumption of alcohol, and daily intake of coffee. RESULTS: Smoking or coffee consumption were not related to active H. pylori infection. Total alcohol consumption was associated with a small, but not statistically significant, decrease in the odds of infection. After adjustment for age, sex, ethnic status, childhood and adult social class, smoking, coffee consumption, and intake of alcoholic beverages other than wine, subjects drinking 3-6 units of wine/wk had an 11% lower risk of H. pylori infection compared with those who took no wine: OR = 0.89, 95% CI = 0.80-0.99. Higher wine consumption was associated with a further 6% reduction in the risk of infection: OR = 0.83, 95% CI = 0.64-1.07. Intake of 3-6 units of beer (but no greater intake) was associated with a similar reduction in the risk of infection when compared to no beer intake (OR = 0.83, 95% CI = 0.75-0.91). CONCLUSIONS: This study indicates that modest consumption of wine and beer (approximately 7 units/wk) protects against H. pylori infection, presumably by facilitating eradication of the organism.