Dietary fat and colon cancer: animal models.

During the past 15 years, human and animal model studies performed in our laboratory indicate that dietary fat plays an important role in the etiology of colon cancer. The effect of dietary fat during the stages of initiation and postinitiation of colon carcinogenesis depends on not only the amount of fat but also the type of fat and its fatty acid composition. Studies conducted in animal models have shown that high intake of dietary corn oil, beef fat, safflower oil, and lard increases colon carcinogenesis, whereas diets high in olive oil, coconut oil, and fish oil are without enhancing effect. The mechanisms by which various types of fat increase colon carcinogenesis are not fully understood; however, in most instances, the high-fat diet seems to enhance colon carcinogenesis through its elevation of agents that act as promoters of tumor development.