Tanvetyanon Tawee, Bepler Gerold
Thoracic Oncology Program, H. Lee Moffitt Cancer Center and Research Institute, University of South Florida, 12902 Magnolia Drive, Tampa FL 33612, USA.
Cancer. 2008 Jul 1;113(1):150-7. doi: 10.1002/cncr.23527.
Some studies have suggested that beta-carotene supplementation may increase the risk of lung cancer, particularly among smokers or former smokers. Beta-carotene, a provitamin A, is available in multivitamins. In the current study, the authors investigated the risk of lung cancer associated with beta-carotene in smokers or former smokers and surveyed the beta-carotene content in national brand multivitamins.
The authors systemically reviewed the published literature using a search of the MEDLINE database and performed a meta-analysis of large randomized trials that reported on the effect of beta-carotene supplementation on the incidence of lung cancer among smokers or former smokers. A sample of multivitamins was evaluated for their beta-carotene content and the suggested daily dosage.
Four studies contributing 109,394 subjects were available for analysis. The average daily beta-carotene dosage in these trials ranged from 20 to 30 mg daily. Among current smokers, beta-carotene supplementation was found to be significantly associated with an increased risk of lung cancer (odds ratio [OR], 1.24; 95% confidence interval [95% CI], 1.10-1.39). Among former smokers, there was no significant increase noted (OR, 1.10; 95% CI, 0.84-1.45). In a sample of 47 common multivitamins, beta-carotene was present in 70% of the identified formulas. The median dosage of beta-carotene was 0.3 mg (range, 0-17.2 mg) daily. The beta-carotene content was found to be significantly higher among multivitamins sold to improve visual health than among other multivitamins, with a median daily dosage of 3 mg (range, 0-24 mg).
High-dose beta-carotene supplementation appears to increase the risk of lung cancer among current smokers. Although beta-carotene was prevalent in multivitamins, high-dose beta-carotene was observed among multivitamin formulas sold to promote visual health.
一些研究表明，补充β-胡萝卜素可能会增加患肺癌的风险，尤其是在吸烟者或曾经吸烟者中。β-胡萝卜素是一种维生素A原，存在于多种维生素中。在本研究中，作者调查了吸烟者或曾经吸烟者中与β-胡萝卜素相关的肺癌风险，并调查了全国知名品牌多种维生素中β-胡萝卜素的含量。
作者通过检索MEDLINE数据库系统地回顾了已发表的文献，并对大型随机试验进行了荟萃分析，这些试验报告了补充β-胡萝卜素对吸烟者或曾经吸烟者肺癌发病率的影响。对一组多种维生素样本的β-胡萝卜素含量和建议的每日剂量进行了评估。
有四项研究共纳入109,394名受试者可供分析。这些试验中β-胡萝卜素的平均每日剂量为每日20至30毫克。在当前吸烟者中，发现补充β-胡萝卜素与肺癌风险增加显著相关（优势比[OR]，1.24；95%置信区间[95%CI]，1.10 - 1.39）。在曾经吸烟者中，未观察到显著增加（OR，1.10；95%CI，0.84 - 1.45）。在47种常见多种维生素的样本中，70%的已识别配方中含有β-胡萝卜素。β-胡萝卜素的中位剂量为每日0.3毫克（范围，0 - 17.2毫克）。发现用于改善视觉健康的多种维生素中的β-胡萝卜素含量显著高于其他多种维生素，中位每日剂量为3毫克（范围，0 - 24毫克）。
高剂量补充β-胡萝卜素似乎会增加当前吸烟者患肺癌的风险。尽管β-胡萝卜素在多种维生素中普遍存在，但在用于促进视觉健康的多种维生素配方中观察到高剂量的β-胡萝卜素。
