Jedrychowski Wieslaw, Maugeri Umberto
Chair of Epidemiology and Preventive Medicine, Jagiellonian University Medical College, Krakow, Poland.
Rev Environ Health. 2009 Jan-Mar;24(1):59-74. doi: 10.1515/reveh.2009.24.1.59.
Environmental factors play an important role in the etiology of colorectal cancer, the second-most common malignancy in both genders in developed countries. Evidence has shown that potential cancer-inducing oxidative damage might be prevented or restricted largely by the presence of dietary antioxidants of plant origin, such as fruits or vegetables. The protective antioxidant effect of fruits and vegetables has been attributed to flavonoids, a major class of phytochemicals naturally occurring in fruits, vegetables, and various foods of plant origin. Yet, epidemiologic cohort studies relating flavonoid intake to risk of colorectal cancer have been sparse and inconclusive. Apples are a rich source of flavonoids and have the second highest level of antioxidant power among all fruits, with peels having a stronger antioxidant activity than apple flesh. A recent reanalysis of several case-control studies in Italy demonstrated a consistent inverse association between apple consumption and the risk of various cancers, and among them ofcolorectal cancer. Here we assessed the potential protective impact of apples on risk of colorectal cancer in the course of a recently performed hospital-based case-control study in a country with dietary habits very different from those of Mediterranean region. The results showed that highest risk of colorectal cancer was among older persons and those who were residents of villages or small towns. The risk of colorectal cancer was inversely correlated with daily number of apple servings, but the most significant reductions of OR estimates were observed for an intake one or more apple servings daily (OR = 0.37, 95% CI: 0.15-0.91). No other fruit was significantly associated with altering the risk of colorectal cancer.
环境因素在结直肠癌的病因中起着重要作用,结直肠癌是发达国家男女中第二常见的恶性肿瘤。有证据表明,潜在的致癌氧化损伤在很大程度上可能会被植物源性膳食抗氧化剂的存在所预防或限制,比如水果或蔬菜。水果和蔬菜的抗氧化保护作用归因于黄酮类化合物,这是一类主要的植物化学物质,天然存在于水果、蔬菜和各种植物源性食物中。然而,将黄酮类化合物摄入量与结直肠癌风险相关联的流行病学队列研究一直很少且尚无定论。苹果是黄酮类化合物的丰富来源,在所有水果中抗氧化能力排名第二,苹果皮的抗氧化活性比苹果果肉更强。最近对意大利几项病例对照研究的重新分析表明,食用苹果与各种癌症风险之间存在一致的负相关,其中包括结直肠癌。在此,我们在一个饮食习惯与地中海地区截然不同的国家,于最近开展的一项基于医院的病例对照研究过程中,评估了苹果对结直肠癌风险的潜在保护作用。结果显示,结直肠癌风险最高的是老年人以及那些居住在村庄或小镇的人。结直肠癌风险与每日苹果食用份数呈负相关,但对于每日摄入一份或多份苹果的情况,观察到比值比(OR)估计值下降最为显著(OR = 0.37,95%置信区间:0.15 - 0.91)。没有其他水果与改变结直肠癌风险有显著关联。