Carcinogenicity testing of complete human diets in rats

So far, in most animal experimental studies isolated food components have been tested. However, as components may interact with each other at different mechanistic levels, testing complex food mixtures more representative for human consumption patterns may better predict the ultimate carcinogenic risk. Studies were performed in Wistar rats using human and rat control diets to assess the effect of relevant food factors such as heat processing and the presence of non-nutrients in vegetables and fruit. The complete human diets, containing meat, bread and eggs, with or without vegetables and fruit, were composed according to mean consumption figures, balanced for macro- and micronutrients. Experiments were performed with spontaneous as well as with chemical-induced tumor models. Heat processing had no effect on tumor induction, while vegetables and fruit only exerted a protective effect on chemically induced tumors in rats fed low-fat animal diets. Data suggest interaction between major food factors in the human diet on colon carcinogenesis.