Block G, Norkus E, Hudes M, Mandel S, Helzlsouer K
University of California, Berkeley, Berkeley, CA 94720, USA.
Am J Epidemiol. 2001 Dec 15;154(12):1113-8. doi: 10.1093/aje/154.12.1113.
Substantial evidence suggests that fruit and vegetable intake reduces the risk of some cancers and other chronic diseases. While a varied diet containing fruits and vegetables may confer benefits greater than those of any single nutrient, it would be useful to have data on the plasma nutrients most influenced by fruit and vegetable intake. The authors examined the correlation between fruit and vegetable intake as measured by the abbreviated CLUE II food frequency questionnaire and several plasma antioxidants. This study includes 116 male subjects aged 35-72 years who were nonsmokers and nonusers of vitamin supplements and who provided blood samples in the CLUE II Study in Washington County, Maryland. Plasma was assayed for ascorbic acid, beta-carotene, beta-cryptoxanthin, and alpha- and gamma-tocopherol. Lipid- and energy-adjusted partial correlation for the relation with fruit and vegetable intake was r = 0.64 for ascorbic acid, r = 0.44 for beta-carotene, and r = 0.50 for beta-cryptoxanthin. While this study does not address efficacy, the stronger association of ascorbic acid with fruit and vegetable intake seen here may imply that ascorbic acid is an important component of the protective effect seen for fruits and vegetables in numerous epidemiologic studies.
大量证据表明，摄入水果和蔬菜可降低患某些癌症及其他慢性病的风险。虽然包含水果和蔬菜的多样化饮食可能带来比任何单一营养素更大的益处，但获取有关受水果和蔬菜摄入量影响最大的血浆营养素数据会很有用。作者通过简化的CLUE II食物频率问卷测量了水果和蔬菜摄入量，并研究了其与几种血浆抗氧化剂之间的相关性。本研究纳入了116名年龄在35至72岁之间的男性受试者，他们不吸烟且不服用维生素补充剂，并在马里兰州华盛顿县的CLUE II研究中提供了血液样本。对血浆中的抗坏血酸、β-胡萝卜素、β-隐黄质以及α-和γ-生育酚进行了检测。经脂质和能量调整后，抗坏血酸与水果和蔬菜摄入量的偏相关系数r = 0.64，β-胡萝卜素为r = 0.44，β-隐黄质为r = 0.50。虽然本研究未涉及功效问题，但此处观察到的抗坏血酸与水果和蔬菜摄入量之间更强的关联可能意味着，抗坏血酸是众多流行病学研究中水果和蔬菜所具有的保护作用的一个重要组成部分。
