Institute of Cancer Epidemiology, Danish Cancer Society, Strandboulevarden 49, DK-2100 Copenhagen Ø, Denmark.
Lung Cancer. 2010 Mar;67(3):275-81. doi: 10.1016/j.lungcan.2009.11.010. Epub 2009 Dec 11.
The role of micronutrients in lung cancer prevention is controversial, as observational and experimental studies have generated contradicting results. These discrepancies between studies may be due to different effects of micronutrients depending on source (diet or supplements). The objective of this study was to evaluate the association between vitamin C, E, folate and beta-carotene and lung cancer risk while focusing on source-specific effects of dietary and supplemental intake. The association was evaluated in a cohort of 55,557 Danes who completed a food frequency questionnaire including information on consumption of vitamin C, E, folate and beta-carotene from diet and supplements. Incidence rate ratios of lung cancer were calculated using Cox proportional hazards models. During a median follow-up of 10.6 years, 721 incident lung cancer cases were diagnosed. We found a significant protective effect of dietary vitamin E intake and a significantly higher lung cancer risk with supplemental beta-carotene and dietary folate intake. All three micronutrients exhibited significant source-specific effects. The harmful effect of dietary folate is, however, most likely to be due to uncontrolled confounding. Our results indicate source-specific effects of vitamin E and beta-carotene in lung cancer prevention with a preventive effect of dietary vitamin E and a harmful effect of supplemental beta-carotene. Future studies on micronutrients and lung cancer should take source into account.
微量元素在肺癌预防中的作用存在争议，因为观察性和实验性研究得出了相互矛盾的结果。这些研究之间的差异可能是由于微量元素的不同作用取决于其来源（饮食或补充剂）。本研究的目的是评估维生素 C、E、叶酸和β-胡萝卜素与肺癌风险之间的关联，同时关注饮食和补充剂摄入的特定来源效应。该关联在一个由 55557 名丹麦人组成的队列中进行了评估，这些人完成了一份食物频率问卷，其中包括饮食和补充剂中维生素 C、E、叶酸和β-胡萝卜素的摄入量信息。使用 Cox 比例风险模型计算肺癌的发病率比。在中位随访 10.6 年期间，诊断出 721 例肺癌新发病例。我们发现饮食中维生素 E 摄入具有显著的保护作用，而补充β-胡萝卜素和饮食中叶酸摄入则显著增加了肺癌风险。这三种微量营养素均表现出显著的特定来源效应。然而，饮食中叶酸的有害作用很可能是由于无法控制的混杂因素所致。我们的研究结果表明，维生素 E 和β-胡萝卜素在肺癌预防中有特定来源的效应，即饮食中维生素 E 具有预防作用，而补充β-胡萝卜素则具有有害作用。未来关于微量元素和肺癌的研究应考虑来源。
