Large intestinal carcinogenesis. I. Promotional effect of dietary fatty acid isomers in the rat model
Hogan, M.L.; Shamsuddin, A.M.
Journal of the National Cancer Institute 73(6): 1293-1296
1984
ISSN/ISBN: 0027-8874 PMID: 6595439 Document Number: 221788
For evaluation of the promotional effects of dietary trans-fatty acids on large intestinal carcinogenesis, 120 inbred female F344 rats were divided into 6 groups and fed a 25% elaidic acid diet, a 25% oleic acid diet or a regular (4.5% fat) chow diet. Ninety animals, 30/dietary group, received weekly i.m. injections of azoxymethane (2 mg/kg; CAS: 25843-45-2). None of the 30 saline-injected control animals, 10/dietary group, fed any of the 3 diets developed tumors. There were twice as many animals with adenocarcinoma of the large intestine from the trans-fatty acid diet group as compared with either the cis-fatty acid diet group or regular diet groups. Chi-square analysis showed that the difference between the incidence of large intestinal carcinomas was not significant between the cis- and trans-fatty acid diets. The difference between the regular diet and trans-fatty acid diet groups was not significant at the 5% level (P = 0.08). A higher, but nonstatistically significant, incidence of nephroblastomas and squamous ear duct neoplasms was also observed in carcinogen-treated animals maintained on each of the high-fat diets as compared with the incidence of both in treated animals fed the regular chow diet.