Narisawa T, Fukaura Y, Yazawa K, Ishikawa C, Isoda Y, Nishizawa Y
Akita University College of Allied Medical Science, Japan.
Cancer. 1994 Apr 15;73(8):2069-75. doi: 10.1002/1097-0142(19940415)73:8<2069::aid-cncr2820730810>3.0.co;2-1.
Epidemiologic and experimental studies suggest that dietary fish oil and vegetable oil high in omega-3 polyunsaturated fatty acids (PUFAs) suppress the risk of colon cancer. The optimal amount to prevent colon carcinogenesis with perilla oil high in omega-3 PUFA alpha-linolenic acid in a 12% medium-fat diet was investigated in female F344 rats. For comparison, safflower oil high in omega-6 PUFA linoleic acid was used.
Thirty or 25 rats at 7 weeks of age in each group received an intrarectal dose of 2 mg N-methyl-N-nitrosourea 3 times weekly in weeks 1 and 2 and were fed the diets with various levels of perilla oil and safflower oil throughout the experiment.
The incidence of colon cancer at the termination of the experiment at week 35 was 40%, 48% and 32% in the rats fed the diets with 3% perilla oil plus 9% safflower oil, 6% perilla oil plus 6% safflower oil, and 12% perilla oil plus 0% safflower oil, respectively, whereas it was 67% in the rats fed the control diet with 0% perilla oil plus 12% safflower oil. The amount of diet consumed and the body weight gain were identical in all of the dietary groups. The ratios of omega-3 PUFA to omega-6 PUFA in the serum and the colonic mucosa at week 35 were increased in parallel to the increased intake of perilla oil.
The results suggest that a relatively small fraction of perilla oil, 25% of total dietary fat, may provide an appreciable beneficial effect in lowering the risk of colon cancer.
流行病学和实验研究表明，富含ω-3多不饱和脂肪酸（PUFAs）的膳食鱼油和植物油可降低结肠癌风险。在雌性F344大鼠中，研究了在12%中等脂肪饮食中，富含ω-3多不饱和脂肪酸α-亚麻酸的紫苏油预防结肠癌发生的最佳剂量。为作比较，使用了富含ω-6多不饱和脂肪酸亚油酸的红花油。
每组30只或25只7周龄大鼠，在第1周和第2周每周3次经直肠给予2mg N-甲基-N-亚硝基脲，并在整个实验过程中喂食含不同水平紫苏油和红花油的饲料。
在第35周实验结束时，喂食含3%紫苏油加9%红花油、6%紫苏油加6%红花油、12%紫苏油加0%红花油饲料的大鼠结肠癌发生率分别为40%、48%和32%，而喂食含0%紫苏油加12%红花油对照饲料的大鼠结肠癌发生率为67%。所有饮食组的饮食摄入量和体重增加量相同。第35周时，血清和结肠黏膜中ω-3多不饱和脂肪酸与ω-6多不饱和脂肪酸的比例随紫苏油摄入量的增加而平行增加。
结果表明，相对少量的紫苏油（占膳食脂肪总量的25%）可能对降低结肠癌风险产生显著的有益作用。
