Department of Epidemiology, Harvard School of Public Health, Boston, MA 02115, USA.
J Natl Cancer Inst. 2011 Jun 8;103(11):876-84. doi: 10.1093/jnci/djr151. Epub 2011 May 17.
Coffee contains many biologically active compounds, including caffeine and phenolic acids, that have potent antioxidant activity and can affect glucose metabolism and sex hormone levels. Because of these biological activities, coffee may be associated with a reduced risk of prostate cancer.
We conducted a prospective analysis of 47,911 men in the Health Professionals Follow-up Study who reported intake of regular and decaffeinated coffee in 1986 and every 4 years thereafter. From 1986 to 2006, 5035 patients with prostate cancer were identified, including 642 patients with lethal prostate cancers, defined as fatal or metastatic. We used Cox proportional hazards models to assess the association between coffee and prostate cancer, adjusting for potential confounding by smoking, obesity, and other variables. All P values were from two-sided tests.
The average intake of coffee in 1986 was 1.9 cups per day. Men who consumed six or more cups per day had a lower adjusted relative risk for overall prostate cancer compared with nondrinkers (RR = 0.82, 95% confidence interval [CI] = 0.68 to 0.98, P(trend) = .10). The association was stronger for lethal prostate cancer (consumers of more than six cups of coffee per day: RR = 0.40, 95% CI = 0.22 to 0.75, P(trend) = .03). Coffee consumption was not associated with the risk of nonadvanced or low-grade cancers and was only weakly inversely associated with high-grade cancer. The inverse association with lethal cancer was similar for regular and decaffeinated coffee (each one cup per day increment: RR = 0.94, 95% CI = 0.88 to 1.01, P = .08 for regular coffee and RR = 0.91, 95% CI = 0.83 to 1.00, P = .05 for decaffeinated coffee). The age-adjusted incidence rates for men who had the highest (≥6 cups per day) and lowest (no coffee) coffee consumption were 425 and 519 total prostate cancers, respectively, per 100 000 person-years and 34 and 79 lethal prostate cancers, respectively, per 100 000 person-years.
We observed a strong inverse association between coffee consumption and risk of lethal prostate cancer. The association appears to be related to non-caffeine components of coffee.
咖啡含有许多具有生物活性的化合物，包括咖啡因和酚酸，具有很强的抗氧化活性，可影响葡萄糖代谢和性激素水平。由于这些生物活性，咖啡可能与前列腺癌风险降低有关。
我们对参加健康专业人员随访研究的 47911 名男性进行了前瞻性分析，这些男性在 1986 年报告了经常饮用和脱咖啡因咖啡的情况，此后每 4 年报告一次。从 1986 年到 2006 年，共发现 5035 例前列腺癌患者，其中包括 642 例致命性前列腺癌患者，定义为致命或转移性。我们使用 Cox 比例风险模型评估了咖啡与前列腺癌之间的关联，通过吸烟、肥胖和其他变量对潜在的混杂因素进行了调整。所有 P 值均为双侧检验。
1986 年的平均咖啡摄入量为每天 1.9 杯。与不饮用咖啡的人相比，每天饮用六杯或更多杯咖啡的人患总体前列腺癌的调整后相对风险较低（RR = 0.82，95%置信区间[CI] = 0.68 至 0.98，P(trend) =.10）。对于致命性前列腺癌，相关性更强（每天饮用超过六杯咖啡的消费者：RR = 0.40，95%CI = 0.22 至 0.75，P(trend) =.03）。咖啡的摄入与非晚期或低级别癌症的风险无关，与高级别癌症仅呈弱负相关。与致命性癌症的负相关与普通咖啡和脱咖啡因咖啡相似（每天一杯的增量：RR = 0.94，95%CI = 0.88 至 1.01，P =.08 对于普通咖啡和 RR = 0.91，95%CI = 0.83 至 1.00，P =.05 对于脱咖啡因咖啡）。每天摄入最高（≥6 杯/天）和最低（无咖啡）咖啡的男性的年龄调整发病率分别为每 10 万人年 425 例和 519 例总前列腺癌，以及每 10 万人年 34 例和 79 例致命性前列腺癌。
我们观察到咖啡摄入与致命性前列腺癌风险之间存在很强的负相关。这种关联似乎与咖啡的非咖啡因成分有关。
