Le Marchand L, Hankin J H, Wilkens L R, Kolonel L N, Englyst H N, Lyu L C
Etiology Program, University of Hawaii Cancer Research Center, Honolulu, USA.
Epidemiology. 1997 Nov;8(6):658-65. doi: 10.1097/00001648-199710000-00008.
We conducted a population-based case-control study among different ethnic groups in Hawaii to evaluate the role of various types and components of fiber, as well as micronutrients and foods of plant origin, on the risk of colorectal cancer. We administered personal interviews to 698 male and 494 female Japanese, Caucasian, Filipino, Hawaiian, and Chinese cases diagnosed during 1987-1991 with adenocarcinoma of the colon or rectum and to 1,192 population controls matched to cases by age, sex, and ethnicity. We used conditional logistic regression to estimate odds ratios, adjusted for caloric intake and other covariates. We found a strong, dose-dependent, inverse association in both sexes with fiber intake measured as crude fiber, dietary fiber, or nonstarch polysaccharides. We found inverse associations of similar magnitude for the soluble and insoluble fiber fractions and for cellulose and noncellulosic polysaccharides. This protective effect of fiber was limited to fiber from vegetable sources, with an odds ratio of 0.6 (95% confidence interval = 0.4-0.9) and 0.5 (95% confidence interval = 0.3-0.7) for the highest compared with the lowest quartile of intake for men and women, respectively. We found associations of the same magnitude for soluble and insoluble vegetable fiber, but no clear association with fiber from fruits or cereals. This pattern was consistent between sexes, across segments of the large bowel (right colon, left colon, and rectum), and among most ethnic groups. The effect of vegetable fiber may be independent of the effects of other phytochemicals, since the effect estimates remained unchanged after further adjustment for other nutrients. Intakes of carotenoids, light green vegetables, yellow-orange vegetables, broccoli, corn, carrots, bananas, garlic, and legumes (including soy products) were inversely associated with risk, even after adjustment for vegetable fiber. The data support a protective role of fiber from vegetables against colorectal cancer, which appears independent of its water solubility property and of the effects of other phytochemicals. The data also indicate that certain vegetables and fruits may be protective against this disease through mechanisms other than their fiber content.
我们在夏威夷不同种族群体中开展了一项基于人群的病例对照研究，以评估不同类型和成分的纤维、微量营养素以及植物源性食物在结直肠癌风险中的作用。我们对1987年至1991年间被诊断患有结肠或直肠癌腺癌的698名男性和494名女性日本、白种、菲律宾、夏威夷和中国病例进行了个人访谈，并对1192名按年龄、性别和种族与病例匹配的人群对照进行了访谈。我们使用条件逻辑回归来估计比值比，并对热量摄入和其他协变量进行了调整。我们发现，以粗纤维、膳食纤维或非淀粉多糖衡量的纤维摄入量在男女两性中均呈现出强烈的、剂量依赖性的负相关。我们发现，可溶性和不溶性纤维组分以及纤维素和非纤维素多糖的负相关程度相似。纤维的这种保护作用仅限于蔬菜来源的纤维，男性和女性摄入量最高四分位数与最低四分位数相比，比值比分别为0.6（95%置信区间=0.4 - 0.9）和0.5（95%置信区间=0.3 - 0.7）。我们发现可溶性和不溶性蔬菜纤维的相关程度相同，但与水果或谷物中的纤维没有明显关联。这种模式在男女之间、大肠各段（右结肠、左结肠和直肠）以及大多数种族群体中都是一致的。蔬菜纤维的作用可能独立于其他植物化学物质的作用，因为在进一步调整其他营养素后，效应估计值保持不变。即使在调整了蔬菜纤维之后，类胡萝卜素、浅绿叶蔬菜、黄橙色蔬菜、西兰花、玉米、胡萝卜、香蕉、大蒜和豆类（包括豆制品）的摄入量与风险仍呈负相关。数据支持蔬菜来源的纤维对结直肠癌具有保护作用，这种作用似乎独立于其水溶性特性以及其他植物化学物质的作用。数据还表明，某些蔬菜和水果可能通过其纤维含量以外的机制预防这种疾病。
