Prostate cancer is the most common non-cutaneous cancer in men in the United States. Several studies have examined the relationship between prostate cancer and antioxidants; however, the results of these studies are inconsistent. This article provides a systematic review of studies on prostate cancer and antioxidant intake from diet and supplements. Tea and coffee appear to offer protection against advanced prostate cancer. Different forms of vitamin E appear to exert different effects on prostate cancer, with alpha-tocopherol potentially increasing and gamma-tocopherol potentially decreasing risk of the disease. There is no strong evidence for a beneficial effect of selenium, vitamin C, or beta-carotene, while lycopene appears to be negatively associated with risk of the disease. The effect of dietary antioxidants on prostate cancer remains undefined and inconclusive, with different antioxidants affecting prostate cancer risk differentially. Further studies are needed to clarify the relationship between antioxidants and prostate cancer risk and to delineate the underlying mechanisms.

BACKGROUND/OBJECTIVES Folic acid supplementation has been suggested to reduce the risk of preeclampsia. However, results from few epidemiologic studies have been inconclusive. We investigated the hypothesis that folic acid supplementation and dietary folate intake before conception and during pregnancy reduce the risk of preeclampsia. SUBJECTS/METHODS A birth cohort study was conducted in 2010–2012 at the Gansu Provincial Maternity & Child Care Hospital in Lanzhou, China. A total of 10 041 pregnant women without chronic hypertension or gestational hypertension were enrolled. RESULTS Compared with nonusers, folic acid supplement users had a reduced risk of preeclampsia (OR = 0.61, 95% CI: 0.43–0.87). A significant dose–response of duration of use was observed among women who used folic acid supplemention during pregnancy only (P-trend = 0.007). The reduced risk associated with folic acid supplement was similar for mild or severe preeclampsia and for early- or late-onset preeclampsia, although the statistical significant associations were only observed for mild (OR = 0.50, 95% CI: 0.30–0.81) and late-onset (OR = 0.60, 95% CI: 0.42–0.86) preeclampsia. The reduced risk associated with dietary folate intake during pregnancy was only seen for severe preeclampsia (OR = 0.52, 95% CI: 0.31–0.87, for the highest quartile of dietary folate intake compared with the lowest). CONCLUSIONS Our study results suggest that folic acid supplementation and higher dietary folate intake during pregnancy reduce the risk of preeclampsia. Future studies are needed to confirm the associations.

The effect of adherence to the World Cancer Research Fund (WCRF) lifestyle recommendations on cancer aggressiveness is unknown. We examined associations between adherence to recommendations and risk of highly aggressive prostate cancer in research subjects enrolled in the North Carolina-Louisiana Prostate Cancer Project (PCaP). We examined associations between adherence to WCRF recommendations and risk of highly aggressive prostate cancer among 2212 newly diagnosed African Americans (AA) or Caucasian Americans (CA) aged 40-70 years in PCaP. Prostate cancer aggressiveness was based on Gleason scores, serum prostate-specific antigens, and TNM stage. Adherence to WCRF recommendations was based on point scores and odds ratios estimated. Results showed that adherence to recommendations was significantly and negatively associated with risk of a highly aggressive prostate cancer. Each additional point in the total adherence score corresponded to a 13% risk reduction. Total adherence score <4 predicted increased risk in both AA (OR = 1.36; 95% CI = 1.01-1.85) and CA (OR = 1.41; 95% CI = 1.01-1.98). Consumption of <500 g red meat per week or ≤125 total kcal/100 g solid food per day is a statistically significant protective factor in the overall cohort. Recommendations aimed at preventing all cancers also may reduce risk of highly aggressive prostate cancer.

Riboflavin carrier protein (RCP) is a growth- and development-specific protein. Here, we characterized the expression of this protein in prostate cancer by polyclonal and monoclonal antibodies against chicken RCP. RCP was localized to both androgen-dependent and independent prostate cancer cell lines. Compared to controls, RCP was over-expressed in all 45 prostate adenocarcinomas, irrespective of the Gleason's score or the stage of the disease. The identified RCP had a molecular weight of 38 kDa, similar to RCP purified from chicken. Presence of this protein was also confirmed by siRNA inhibition analysis. Antibodies to chicken RCP inhibited incorporation of tritiated thymidine into DNA and prevented riboflavin uptake in PC3 prostate cancer cells, suggesting a critical function of this protein in prostate cancer cell growth. These data suggest that RCP can be used as a tumor biomarker in prostate cancer.

BackgroundAfrican Americans (AAs) have lower circulating 25-hydroxyvitamin D3 [25(OH)D3] concentrations and higher prostate cancer (CaP) aggressiveness than other racial/ethnic groups. The purpose of the current study was to examine the relationship between plasma 25(OH)D3, African ancestry and CaP aggressiveness among AAs and European Americans (EAs).MethodsPlasma 25(OH)D3 was measured using LC-MS/MS (Liquid Chromatography Tandem Mass Spectrometry) in 537 AA and 663 EA newly-diagnosed CaP patients from the North Carolina-Louisiana Prostate Cancer Project (PCaP) classified as having either ‘high’ or ‘low’ aggressive disease based on clinical stage, Gleason grade and prostate specific antigen at diagnosis. Mean plasma 25(OH)D3 concentrations were compared by proportion of African ancestry. Logistic regression was used to calculate multivariable adjusted odds ratios (OR) and 95% confidence intervals (95%CI) for high aggressive CaP by tertile of plasma 25(OH)D3.ResultsAAs with highest percent African ancestry (>95%) had the lowest mean plasma 25(OH)D3 concentrations. Overall, plasma 25(OH)D3 was associated positively with aggressiveness among AA men, an association that was modified by calcium intake (ORT3vs.T1: 2.23, 95%CI: 1.26–3.95 among men with low calcium intake, and ORT3vs.T1: 0.19, 95%CI: 0.05–0.70 among men with high calcium intake). Among EAs, the point estimates of the ORs were <1.0 for the upper tertiles with CIs that included the null.ConclusionsAmong AAs, plasma 25(OH)D3 was associated positively with CaP aggressiveness among men with low calcium intake and inversely among men with high calcium intake. The clinical significance of circulating concentrations of 25(OH)D3 and interactions with calcium intake in the AA population warrants further study.