Nicholson M L, Neoptolemos J P, Clayton H A, Talbot I C, Bell P R
University Department of Surgery, Leicester Royal Infirmary, UK.
Carcinogenesis. 1990 Dec;11(12):2191-7. doi: 10.1093/carcin/11.12.2191.
The influence of dietary fats on azoxymethane-induced colorectal carcinogenesis and erythrocyte, adipose, colon mucosa and tumour tissue fatty acids was investigated in 228 Wistar rats. The two main diets compared were beef suet rich in saturated fatty acids and corn oil rich in a linoleic acid, an N-6 polyunsaturated fatty acid. The animals were placed in one of four dietary groups: A = 5% saturated fat, B = 20% saturated fat, C = 5% N-6 fat and D = 20% N-6 fat. There was no difference in the number of adenomas between any of the dietary groups. The mean (+/- SEM) carcinoma yield per rat was A = 0.93 +/- 0.28, B = 1.93 +/- 0.50, C = 0.70 +/- 0.07, D = 0.13 +/- 0.04; the tumour yields in rats fed the saturated fat diets were significantly different from each other and from those fed the N-6 fat diets. The fatty acid profiles in all tissues were dependent upon the type and level of dietary fat and the tissue type. Arachidonate was higher in tumours compared to normal mucosa. Significant correlations were found between adipose linoleate (reflecting dietary intake) and tumour oleate and tumour arachidonate but not with the colorectal mucosa of control animals. This is the first in vivo study to show reduced colorectal carcinogenesis by N-6 polyunsaturated fatty acids.
在228只Wistar大鼠中研究了膳食脂肪对氧化偶氮甲烷诱导的结直肠癌发生以及红细胞、脂肪、结肠黏膜和肿瘤组织脂肪酸的影响。所比较的两种主要膳食分别是富含饱和脂肪酸的牛脂和富含亚油酸（一种N-6多不饱和脂肪酸）的玉米油。将动物分为四个膳食组之一：A = 5%饱和脂肪，B = 20%饱和脂肪，C = 5% N-6脂肪，D = 20% N-6脂肪。任何膳食组之间腺瘤数量均无差异。每只大鼠的平均（±标准误）癌发生率为：A = 0.93 ± 0.28，B = 1.93 ± 0.50，C = 0.70 ± 0.07，D = 0.13 ± 0.04；喂食饱和脂肪膳食的大鼠的肿瘤发生率彼此之间以及与喂食N-6脂肪膳食的大鼠的肿瘤发生率均有显著差异。所有组织中的脂肪酸谱取决于膳食脂肪的类型和水平以及组织类型。与正常黏膜相比，肿瘤中的花生四烯酸盐含量更高。发现脂肪组织中的亚油酸酯（反映膳食摄入量）与肿瘤中的油酸酯和花生四烯酸盐之间存在显著相关性，但与对照动物的结肠黏膜无关。这是第一项表明N-6多不饱和脂肪酸可降低结直肠癌发生的体内研究。
