ABSTRACT
This chapter examines the effects of a nutritional "stress" diet on the colonic epithelium, based on a defined semisynthetic diet, modified to contain 4 suggested risk factors of the human Western-style diet: increased fat and phosphate and decreased calcium and vitamin D content. The dietary fat increases the levels of free fatty acid and free bile acids in the colonic lumen. This damage can be prevented by increasing dietary calcium. The rodents on ad libitum feeding tended to ingest about 20% less feed of the higher caloric density stress diets. The dietary intake of these essential materials was thus roughly comparable in the different groups, with the exception of the altered items that constitute the stress components. The level of calcium used, 1.3 mg/kcal, is equivalent to about 3,100 mg of calcium in a human 2,400 kcal diet, a high nutritional level. In the mice, it was completely effective in preventing hyperproliferation and hyperplasia but not completely in rats.
