| Popis: |
Publisher Summary Concurrent outbreaks of disease in poultry and fish in different parts of the world during early 1960 focused major attention on the significance of diet contamination in the induction of cancer. These outbreaks were related to the adoption of specially prepared commercial food rations. Trout feed composed of rations put up in the form of dry pellets. The high prevalence of hepatomas in trout occurred following the wide-scale use of these commercial feeds. Dry pelleted rations for trout composed of steam- or flame-dried fish meal, cottonseed meal, meat scraps, and dried milk as protein sources. Prior to use of these components a wet diet, consisting largely of viscera from sheep, swine, cattle, and other fish, was used in addition to ground beef and horse meat. These diets of unprocessed products were not known to produce hepatomas. These products may undergo unfavorable storage conditions with subsequent fungal contamination. The genesis of tumors is influenced to a lesser or greater degree by the nutrient environment furnished in the host. In the processing of food by heat or radiation sterilization, degradation products are produced. Heat dehydration and over processing produces toxic lipid polymers. In the processing of foods for improvement of texture, flavor, and color, innocuous and quite beneficial chemical additives are used, but a few demonstrate toxicity and carcinogenicity. Another source of contamination is from bacteria and/or bacterial metabolites, especially those that have clinical and pathological significance. Animals and man are exposed to complex and unknown integrative effects that are possible with respect to the action of the wide spectrum of toxins and carcinogens. Thus, the chemistry, toxicology, and carcinogenicity of these many natural products must now be fully investigated to ascertain their contribution to the problem of environmental carcinogenesis confronting animals and man. |
