Tang Li, Zirpoli Gary R, Guru Khurshid, Moysich Kirsten B, Zhang Yuesheng, Ambrosone Christine B, McCann Susan E
Department of Cancer Prevention and Control, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
Cancer Epidemiol Biomarkers Prev. 2008 Apr;17(4):938-44. doi: 10.1158/1055-9965.EPI-07-2502.
Cruciferous vegetables contain isothiocyanates, which show potent chemopreventive activity against bladder cancer in both in vitro and in vivo studies. However, previous epidemiologic studies investigating cruciferous vegetable intake and bladder cancer risk have been inconsistent. Cooking can substantially reduce or destroy isothiocyanates, and could account for study inconsistencies. In this hospital-based case-control study involving 275 individuals with incident, primary bladder cancer and 825 individuals without cancer, we examined the usual prediagnostic intake of raw and cooked cruciferous vegetables in relation to bladder cancer risk. Odds ratios (OR) and 95% confidence intervals (CI) were estimated with unconditional logistic regression, adjusting for smoking and other bladder cancer risk factors. We observed a strong and statistically significant inverse association between bladder cancer risk and raw cruciferous vegetable intake (adjusted OR for highest versus lowest category = 0.64; 95% CI, 0.42-0.97), with a significant trend (P = 0.003); there were no significant associations for fruit, total vegetables, or total cruciferous vegetables. The associations observed for total raw crucifers were also observed for individual raw crucifers. The inverse association remained significant among current and heavy smokers with three or more servings per month of raw cruciferous vegetables (adjusted ORs, 0.46 and 0.60; 95% CI, 0.23-0.93 and 0.38-0.93, respectively). These data suggest that cruciferous vegetables, when consumed raw, may reduce the risk of bladder cancer, an effect consistent with the role of dietary isothiocyanates as chemopreventive agents against bladder cancer.
十字花科蔬菜含有异硫氰酸盐，在体外和体内研究中均显示出对膀胱癌具有强大的化学预防活性。然而，先前调查十字花科蔬菜摄入量与膀胱癌风险的流行病学研究结果并不一致。烹饪会大幅减少或破坏异硫氰酸盐，这可能是研究结果不一致的原因。在这项基于医院的病例对照研究中，纳入了275例新发原发性膀胱癌患者和825例无癌症个体，我们研究了诊断前通常食用的生熟十字花科蔬菜与膀胱癌风险的关系。通过无条件逻辑回归估计比值比（OR）和95%置信区间（CI），并对吸烟和其他膀胱癌风险因素进行了调整。我们观察到膀胱癌风险与生十字花科蔬菜摄入量之间存在强烈且具有统计学意义的负相关（最高类别与最低类别调整后的OR = 0.64；95% CI，0.42 - 0.97），且存在显著趋势（P = 0.003）；水果、总蔬菜或十字花科蔬菜总量与膀胱癌风险无显著关联。对于单个生十字花科蔬菜的观察结果与总生十字花科蔬菜的观察结果一致。在当前吸烟者和重度吸烟者中，每月食用三份或更多份生十字花科蔬菜时，这种负相关仍然显著（调整后的OR分别为0.46和0.60；95% CI分别为0.23 - 0.93和0.38 - 0.93）。这些数据表明，生的十字花科蔬菜可能会降低膀胱癌风险，这一效应与膳食异硫氰酸盐作为膀胱癌化学预防剂的作用一致。
