文章：

饮食与癌症预防：观察与实验的作用

Diet and cancer prevention: the roles of observation and experimentation

原文发布日期：2008-08-07

DOI: 10.1038/nrc2441

类型: Review Article

开放获取: 否

要点：

1. Chemoprevention is defined as the use of pharmacological agents (including nutrients) to impede, arrest or reverse carcinogenesis and has been used to test the efficacy of numerous nutrients and other dietary factors.
2. Observational epidemiology and experimentation by randomized controlled trials (RCTs) have been used to evaluate dietary factors in cancer chemoprevention; however, consistency in findings has been elusive.
3. The study of diet and cancer associations in humans poses a variety of challenges owing to the complexity in measuring dietary intake as well as the multifactorial nature of the cancer endpoints.
4. In several circles, RCTs are viewed as being more credible than observational studies.
5. When discrepant results between observational studies and RCTs are reported, careful consideration needs to be given to the details of each set of studies before accepting RCTs as valid and those of observational studies as biased.
6. Considerations in the interpretation of results from RCTs include the background diet of the study population; the dose, duration and timing of the intervention; the precise form of the nutrient or dietary factor tested; and compliance with the intervention.

要点翻译：

1. 化学预防是指使用药物（包括营养素）来阻止、遏制或逆转癌变过程，并已被用于测试多种营养素及其他膳食因素的功效。
2. 观察性流行病学与随机对照试验的实验方法已被应用于评估膳食因素在癌症化学预防中的作用，但研究结果始终难以保持一致。
3. 由于膳食摄入测量的复杂性以及癌症终点的多因素性质，研究饮食与癌症关联在人类中面临诸多挑战。
4. 在某些领域，随机对照试验被认为比观察性研究更具可信度。
5. 当观察性研究与随机对照试验出现不一致结果时，需要仔细考量每组研究的具体细节，而非简单认定随机对照试验结果必然可靠、观察性研究结果必然存在偏倚。
6. 解读随机对照试验结果时需考虑的因素包括：研究人群的基础饮食状况；干预措施的剂量、持续时间和时机；所测试营养素或膳食因素的具体形态；以及受试者对干预方案的依从性。

英文摘要：

Observational epidemiology and experimentation by randomized controlled trials (RCTs) have been used to evaluate dietary factors in cancer prevention; however, consistency in findings has been elusive. In several circles, RCTs are viewed as more credible than observational studies. As the testing of dietary epidemiological findings in RCTs has been more common for colorectal cancer than for other cancers, we use experience with this malignancy to critically appraise the reasons for discrepancies between results of observational and experimental studies.

摘要翻译： 

观察性流行病学与随机对照试验（RCT）已被用于评估饮食因素在癌症预防中的作用；然而，研究结果的一致性始终难以达成。在多个研究领域中，RCT被认为比观察性研究更具可信度。由于饮食流行病学发现已在结直肠癌中较其他癌症更频繁地接受RCT验证，我们借这一恶性肿瘤的经验，批判性地评估观察性与实验性研究结果不一致的原因。

原文链接：

Diet and cancer prevention: the roles of observation and experimentation