Large Intestinal Carcinogenesis. I. Promotional Effect of Dietary Fatty Acid Isomers in the Rat Model&lt;xref ref-type="fn" rid="FN2"&gt;2&lt;/xref&gt;&lt;xref ref-type="fn" rid="FN3"&gt;3&lt;/xref&gt;

Marian L Hogan ,Abulkalam M Shamsuddin

doi:10.1093/jnci/73.6.1293

Abstract

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 per dietary group, received weekly im injections of azoxymethane (2 mg/kg; CAS: 25843-45-2). None of the 30 saline-injected control animals, 10 per dietary group, fed any of the three 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 = .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.

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