OBJECTIVE To investigate whether the protection observed for some micronutrients, such as beta-carotene, in several observational studies may simply reflect vegetable and fruit intake. DESIGN A case-control study conducted in Italy. SUBJECTS The subjects were 1225 colon cancer patients, 728 rectal cancer patients and 4154 hospital controls. RESULTS For the 16 micronutrients considered, the more closely a micronutrient was correlated with total vegetable and fruit intake, the more it appeared protective against colorectal cancer. CONCLUSION When studying the effect of a nutrient on disease risk in an observational setting, its relation to other nutrients and foods must be taken into account.

中文翻译：

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蔬菜，水果与微量营养素摄入之间的关系。病例对照研究中比值比的含义。

目的要研究在一些观察性研究中是否观察到对某些微量营养素（如β-胡萝卜素）的保护作用，可能仅反映了蔬菜和水果的摄入量。设计在意大利进行的病例对照研究。受试者为1225名结肠癌患者，728名直肠癌患者和4154名医院对照组。结果对于所考虑的16种微量营养素，微量营养素与蔬菜和水果的总摄入量之间的相关性越强，就越能抵抗结肠直肠癌。结论在观察环境中研究营养素对疾病风险的影响时，必须考虑其与其他营养素和食物的关系。