Singletary K, Nelshoppen J, Wallig M
Division of Foods and Nutrition, University of Illinois at Urbana-Champaign 61801, USA.
Carcinogenesis. 1995 Apr;16(4):959-64. doi: 10.1093/carcin/16.4.959.
A majority of epidemiological investigations report an association between risk for breast cancer in women and alcohol consumption. However, evidence for an enhancing effect of ethanol on chemically induced rat mammary tumorigenesis is limited and inconsistent. The present study was conducted to evaluate the influence of low to high ethanol intakes (15, 20 or 30% of calories) as part of a defined, liquid diet on both the initiation and promotion stages of N-methyl-N-nitrosourea (MNU)-induced rat mammary tumorigenesis. Ethanol consumed by rats at 15% of calories during either the initiation or promotion stages increased the number of mammary adenocarcinomas compared to isocaloric controls. Ethanol intake at 20% of calories only during the promotion stage resulted in an increase in the number of mammary adenocarcinomas compared to controls. No enhancing effect of dietary ethanol at 30% of calories on either stage of tumorigenesis was observed in comparison to isocaloric controls. Therefore, ethanol at specific intakes can enhance the initiation and promotion stages of MNU-induced rat mammary tumorigenesis. There was not, however, a corresponding increase in mammary tumor development at the highest intake of ethanol evaluated. Possible reasons for this latter lack of effect of ethanol are discussed.
大多数流行病学调查都报告了女性患乳腺癌的风险与饮酒之间存在关联。然而，关于乙醇对化学诱导的大鼠乳腺肿瘤发生有增强作用的证据有限且不一致。本研究旨在评估低至高乙醇摄入量（占卡路里的15%、20%或30%）作为特定液体饮食的一部分，对N-甲基-N-亚硝基脲（MNU）诱导的大鼠乳腺肿瘤发生起始阶段和促进阶段的影响。在起始阶段或促进阶段，大鼠摄入占卡路里15%的乙醇，与等热量对照组相比，乳腺腺癌的数量增加。仅在促进阶段摄入占卡路里20%的乙醇，与对照组相比，乳腺腺癌的数量增加。与等热量对照组相比，未观察到占卡路里30%的饮食乙醇对肿瘤发生的任何阶段有增强作用。因此，特定摄入量的乙醇可增强MNU诱导的大鼠乳腺肿瘤发生的起始阶段和促进阶段。然而，在所评估的最高乙醇摄入量下，乳腺肿瘤的发展并没有相应增加。文中讨论了乙醇后一种缺乏作用的可能原因。
