Re:【medical-news】西红柿预防前列腺癌的神话破灭

No Magic Tomato? Study Breaks Link between Lycopene and Prostate Cancer Prevention
西红柿预防前列腺癌的神话破灭
May 17, 2007
PHILADELPHIA -- Tomatoes might be nutritious and tasty, but don't count on them to prevent prostate cancer. In the May issue of Cancer Epidemiology, Biomarkers & Prevention, researchers based at the National Cancer Institute and Fred Hutchinson Cancer Research Center report that lycopene, an antioxidant predominately found in tomatoes, does not effectively prevent prostate cancer. In fact, the researchers noted an association between beta-carotene, an antioxidant related to lycopene, and an increased risk for aggressive prostate cancer.
费城——西红柿虽然营养可口，但别指望它用来预防前列腺癌。来自美国国家癌症研究所和佛瑞德·哈金森癌症研究中心的研究人员在《癌症流行病学、生物标记物和预防》5月刊发表的报告指出，西红柿中的主要抗氧化成分——番茄红素，不能有效地预防前列腺癌。事实上，研究人员注意到，与番茄红素有关的另一抗氧化成分β-胡萝卜素，与增加前列腺癌转移的风险有关。
According to the researchers, the study is one of the largest to evaluate the role of blood concentrations of lycopene and other carotenoid antioxidants in preventing prostate cancer. Study data were derived from over 28,000 men enrolled in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, an ongoing, randomized National Cancer Institute trial to evaluate cancer screening methods and to investigate early markers of cancer.
据研究人员称，该研究是评价血液中番茄红素以及其它类胡萝卜素抗氧化剂含量与预防前列腺癌关系的最大规模研究之一，研究数据来源于“前列腺癌、肺癌、结直肠癌和卵巢（PLCO）癌筛选试验”登记入组的28000名男性患者，该试验是国家癌症研究所正在进行的一项评价癌症筛选方法和癌症早期标记物研究的随机试验。
"It is disappointing, since lycopene might have offered a simple and inexpensive way to lower prostate cancer risk for men concerned about this common disease," said Ulrike Peters, Ph.D., M.P.H., of the Fred Hutchinson Cancer Research Center. "Unfortunately, this easy answer just does not work."
“令人失望，因为番茄红素或许可以提供一种简单而便宜的降低前列腺癌发病风险的方法，遗憾的是，此路不通。” 佛瑞德·哈金森癌症研究中心的Ulrike Peters博士说道。
Previous studies suggested that a diet rich in lycopene protected against prostate cancer, spurring commercial and public interest in the antioxidant. Antioxidants protect against free radicals, highly reactive atoms and molecules that can damage DNA and other important molecules in the cell. Since free radical damage increases with age, there has been a long-held suspicion in the scientific community that free radical damage could increase the risk of prostate cancer, a disease that has been clearly associated with age.
Subsequent studies of the potentially protective role of lycopene have been contradictory or inconclusive, according to Peters. In a 2006 study, she and her colleagues looked at the dietary intake of more than 25 tomato-based foods, also using data from the PLCO trial, and found no overall association between lycopene intake and prostate cancer.
先前的研究表明，富含番茄红素的饮食可预防前列腺癌，这引起了商业和公众对这种抗氧化剂的兴趣。抗氧化剂可对抗自由基，自由基是高活性的原子或分子，可损伤细胞中的DNA和其它重要分子。由于自由基损伤随龄增加，因此科学界曾长期怀疑，自由基损伤可能增加前列腺癌患病风险，因为已经非常明确，前列腺癌发病率与年龄有关。据Peters称，后来有关番茄红素可能的预防作用的研究结果或相互矛盾或不能肯定。她及其同事在2006年的研究中，考察了多于25种的西红柿为主食物，并采用了PLCO试验数据，发现从总体上看来，番茄红素的摄入与前列腺癌不存在相关性。
In their current study, the researchers followed over 28,000 men between the ages of 55 and 74, enrolled in the PLCO Trial, with no history of prostate cancer. The men were initially screened through a PSA test and digital rectal exam, and were then followed through routine exams and screenings until first occurrence of prostate cancer, death or the end of the trial in 2001. At the beginning of the trial, the men gave a blood sample and completed a questionnaire related to their health, diet and lifestyle.
在此次研究中，他们跟踪研究了28000多名年龄在55-74岁之间、无前列腺癌史的入组PLCO试验的男性。他们最初采用PSA检验和直肠指诊法进行筛查，此后进行常规检查和筛查，直到首次查出前列腺癌、死亡或2001年试验结束为止。在试验开始时，受试者进行血样分析和完成有关健康、饮食及生活方式的问卷调查。
The researchers focused on non-Hispanic Caucasian men, as the small number of cases among other ethnic groups was statistically insignificant. They found no significant difference between those who had prostate cancer and those who did not in relation to the concentration of lycopene in their bloodstream. "Our results do not offer support for the benefits of lycopene against prostate cancer," Peters said.
由于其他种族的少数病例缺少统计学意义，因此研究人员重点关注非西班牙裔白种男性。他们发现，前列腺癌患者与血液中番茄红素浓度无关的人们之间无显著性差异。“我们的结果对番茄红素预防前列腺癌的益处不能提供支持。” Peters 说道。
Most surprisingly, says Peters, was the relationship between increased risk of aggressive prostate cancer - defined as disease that has spread beyond the prostate - and beta-carotene, another antioxidant found in many vegetables and commonly used as a dietary supplement.
This unexpected observation "may be due to chance, however beta carotene is already known to increase risk of lung cancer and cardiovascular disease in smokers," Peters said.
更为吃惊的是，前列腺癌的转移风险的提高与β-胡萝卜素有关。β-胡萝卜素是许多蔬菜中含有的另一种抗氧化剂，并常作为食品添加剂应用。该意料之外的结果“或许事出偶然，但β-胡萝卜素增加吸烟者肺癌和心血管疾病患病风险，却早已为人所知。” Peters说道。
"While it would be counter-productive to advise people against eating carrots and leafy vegetables, I would say to be cautious about taking beta carotene supplements, particularly at high doses, and consult a physician," Peters said.
“与其劝说人们拒绝食用胡萝卜和叶类蔬菜会产生非建设性效果，我想说的是，服用β-胡萝卜素添加剂，特别是大剂量服用时，应该慎重，并咨询医生。”
Funding for this study was provided through the National Cancer Institute and the U.S. Department of Health and Human Services.
该研究由国家癌症研究所和美国卫生和公共福利部资助。
编译：
西红柿预防前列腺癌的神话破灭
据美国癌症研究协会5月17日消息，西红柿虽然营养可口，但别指望它用来预防前列腺癌。来自美国国家癌症研究所和佛瑞德·哈金森癌症研究中心的研究人员发表在《癌症流行病学、生物标记物和预防》5月刊的一篇报告指出，西红柿中的主要抗氧化成分——番茄红素，不能有效地预防前列腺癌。研究人员还观察到，与番茄红素有关的另一抗氧化成分β-胡萝卜素，与增加前列腺癌转移的风险有关。
据研究人员称，该研究是评价血液中番茄红素以及其它类胡萝卜素抗氧化剂含量与预防前列腺癌关系的最大规模研究之一，研究数据来源于“前列腺癌、肺癌、结直肠癌和卵巢癌（PLCO）筛选试验”登记入组的28000名男性患者，该试验是国家癌症研究所正在进行的一项评价癌症筛选方法和癌症早期标记物研究的随机试验。
先前的研究表明，富含番茄红素的饮食可预防前列腺癌，这引起了商业和公众对这种抗氧化剂的兴趣。抗氧化剂可对抗自由基，自由基是高活性的原子或分子，可损伤细胞中的DNA和其它重要分子。由于自由基损伤随龄增加，因此科学界曾长期怀疑，自由基损伤可能增加前列腺癌患病风险，因为已经非常明确，前列腺癌发病率与年龄有关。据Peters称，后来有关番茄红素可能的预防作用的研究结果或相互矛盾或不能肯定。她及其同事在2006年的研究中，考察了多于25种的西红柿为主食品，并采用了PLCO试验数据，发现从总体上看来，番茄红素的摄入与前列腺癌不存在相关性。
在此次研究中，他们跟踪研究了28000多名年龄在55-74岁之间、无前列腺癌史的入组PLCO试验的男性。他们最初采用PSA检验和直肠指诊法进行筛查，此后进行常规检查和筛查，直到首次查出前列腺癌、死亡或2001年试验结束为止。在试验开始时，受试者进行血样分析和完成有关健康、饮食及生活方式的问卷调查。由于其他种族的少数病例缺少统计学意义，因此研究人员重点关注非西班牙裔白种男性。结果他们发现，前列腺癌患者与血液中番茄红素浓度无关的人们之间无显著性差异。研究结果对番茄红素预防前列腺癌的益处不能提供支持。更为吃惊的是，前列腺癌的转移风险的提高与β-胡萝卜素有关。β-胡萝卜素是许多蔬菜中含有的另一种抗氧化剂，并常作为食品添加剂应用。
Peters称，该意料之外的结果或许事出偶然，但β-胡萝卜素增加吸烟者肺癌和心血管疾病患病风险，却早已为人所知。她提醒人们说，
服用β-胡萝卜素添加剂，特别是大剂量服用时，应该慎重，并咨询医生。
该研究由国家癌症研究所和美国卫生和公共福利部资助。