Carcinogens dietary processing

For example, 7,12-dimethylbenz[a]anthracene is a particularly potent carcinogen for the mammary gland of young female Sprague-Dawley rats after oral or intravenous administration (25,26), dietary benzo[a]pyrene leads to leukemia, lung adenoma and stomach tumors in mice (27), and either of these hydrocarbons can induce hepatomas in male mice when injected on the first day of life (28). Nevertheless, the mouse skin system has proved to be particularly valuable because of the rapidity of tumor induction, the ease of detection of tumors and because the multi-stage nature of the carcinogenic process was experimentally established in this system. 

The presence of chemicals, which might be the carcinogen itself, its metabolites or even some other chemical - including some normal dietary components - that may restrict or enhance conversion or development, at several different points of the process. 

In addition to the walls of the parenchyma cells, the walls of the periderm (skin) cork cells form part of the total intake of dietary fiber and a waste product of potato processing for food as well as for starch. Although much is known about the suberin present in these cell walls (Bernards, 2002 Franke and Schreiber, 2007 Grafos and Santos, 2007), little is known about their polysaccharides (Harris et al., 1991). Nonetheless, because of the presence of suberin, these cell walls are able to adsorb hydrophobic dietary carcinogens and their intake may be important in the prevention of colorectal cancer (Harris et al., 1991 Ferguson and Harris, 1998, 2001). 

Current research in animal models which suggests that the carcinogenic response to a variety of colon carcinogens is enhanced by the dietary fat and inhibited by several dietary fibers, indicates that these nutritional factors may operate during the promotional phase of carcinogenesis. The carcinogenic process in humans may... 

The diet should meet all nutritional requirements of the species tested and should be free from impurities that might influence the outcome of the test. Dietary contaminants and levels of various nutrients have been shown to alter physiologic processes of animals. Rodents should be fed and watered ad libitum with food replaced at least weekly. When a nonrodent such as the dog is used, it should be fed daily. At present, three types of diets are used conventional (standard), synthetic, and various open-formula diets. Of these, the first two are more widely used in carcinogenicity bioassays. Whichever diet is chosen, suppliers must ascertain by periodic monitoring the nutrient quality and the contaminant level in the basal diet. The researchers should know the effect of the dietary regimen on metabolism and animal longevity. 

Process flavors are widely used in prepared foods to enhance the taste and odor of these products. Process flavors were identified as potential dietary sources of heterocyclic amines, both monocyclic heteroaromatic amines (MHAs), and polycyclic heteroaromatic amines (PHAs). MHAs are innocuous substances, some of which have flavoring characteristics. However, PHAs are reported to be potent mutagens and animal carcinogens (Munro et aL, 1993) and have been the subject of significant interest regarding their potential human health risk. 

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