Colorectal cancer dietary fiber

In summary, the true association between most dietary factors and the risk of colon cancer is unclear. The protective effects of fiber, calcium, and a diet low in fat are not completely known. Lifestyle factors such as NSAID use and hormone use appear to decrease the risk of colorectal cancer, whereas physical inactivity, alcohol use, and smoking appear to increase the risk of colon cancer. Clinical risk factors and genetic mutations are well-known risks for colon cancer. 

Terry P, Giovannucci E, Michels KB, Bergkvist L, Hansen H, Holmberg L and Wolk A. 2001. Fruit, vegetables, dietary fiber, and risk of colorectal cancer. J Natl Cancer Inst 93(7) 525-533. 

Tabernero M, Serrano J and Saura-Calixto F. 2007. Dietary fiber intake in two European diets with high (Copenhagen, Denmark) and low (Murcia, Spain) colorectal cancer incidence. J Agric Food Chem 55 94443-94449. 

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). 

In the study on colorectal cancer (Table 20.4), a reduced risk was found for increasing intake of anthocyanidins (OR, 0.67 for the highest versus the lowest quintile,p-trend, 0.001), flavonols (OR, 0.64,p-trend < 0.001), flavones (OR, 0.78, p-trend, 0.004), and isoflavones (OR, 0.76, p-trend, 0.001). [Rossi et al., 2006], The estimates did not substantially differ for colon and rectal cancers. After allowance for fruit and vegetable consumption, for dietary fiber, or for micronutrients previously associated to this tumor including vitamin C, the associations with flavonoids did not change by more than 10%. A recent case-control study of 1456 pairs of cases and controls conducted in Sweden confirmed a significant decrease in risk of colorectal cancer for intake of anthocyanidins and flavonols [Theodoratou et al., 2007], but there was no relation for isoflavones and flavones. However, the results on isoflavones and flavones are questionable due to the unusually and generally low intakes of the populations studied. In the Italian population, anthocyanidins were derived mainly from wine, red fruit, and onions, and flavonols from apples or pears, wine, and mixed salads. 

Dietary Fiber. There is no conclusive evidence to indicate that total dietary fiber exerts a protective effect against colorectal cancer in humans. Both epidemiological and laboratory reports suggest that if there is such an effect, specific components of fiber, rather than total fiber, are more likely to be responsible. 

Baron, J.A., Dietary fiber and colorectal cancer an ongoing saga, JAMA, 295, 2904—2906, 2005. 

Park, Y., Hunter, D.J., Spiegelman, D., et al., Dietary fiber intake and risk of colorectal cancer a pooled analysis of prospective cohort studies, JAMA, 294, 2849-2857, 2005. 

A number of animal studies have shown that dietary fibers, which liberate a constant and elevated supply of butyrate to the colon, are the most effective for prevention of chemically induced colon tumors. Moreover, the level of butyric acid in the colonic lumen of patients with colorectal cancer and adenomas was found to be lower than that in healthy individuals (Parodi, 2004). 

When collecting biospecimens for biomarker analyses, what other data should be collected to address possible confounders to the measurements In the example of FICA intake and colorectal cancer risk, some possible confounders to consider would be other sources of HCAs, such as cigarette smoking, and factors that may alter FICA metabolism, such as antioxidants and dietary fiber. 

Large bowel, cancer of, see Colorectal cancer Largo intestine, dietary fiber and, 144-147 Laxative abuse, 723... 

Le Marchand L, Hankin JH, Wilkens LR, et al. Dietary fiber and colorectal cancer risk. Epidemiology 1997 8 658-665. 

Although early studies suggest that a substantial increase in daily dietary fiber and/or decrease in dietary fat intake might significantly, reduce colorectal cancer risk results from recent ran-... 

To date, findings from randomized trials have failed to demonstrate a protective effect of low-fat high-fiber fruit and vegetable dietary intake in reducing risk of recurrence of colorectal adenomas or colorectal cancer. 

Fuchs CS, Giovannucci EL, Colditz GA. Dietary fiber and the risk of colorectal cancer and adenoma in women. N Engl J Med 1999 340 169-176. 

Wakai, K., Date, C., Fukui, M., Tamakoshi, K., Watanabe, Y., Hayakawa, N., Kojima, M., Kawado, M., Suzuki, K., Hashimoto, S., Tokudome, S., Ozasa, K., et al. (2007). Dietary fiber and risk of colorectal cancer in the Japan collaborative short study. Cancer Epidemiol. Biomarkers Prev. 16(4), 668-675. 

M.C. Jansen, H.B Beuno-de-Mesquita, R. Buzina, F. Fidanza, A. Minotti, H. Blackburn, A.M. Nissenen, F.J. Kok, and D. Kromhout. Dietary fiber and plant foods in relation to colorectal cancer mortality The seven countries study. Int. J. Cancer, 81 174-179 (1999). 

Despite our increased knowledge of the synthesis, secretion and enterohepatic circulation of bile salts, several aspects of the effects of these sterol metabolites on the physiology of the intestine itself have not been emphasized and are poorly understood. This becomes of greater significance when we consider that bile acids, particularly chenodeoxycholic acid and ursodeoxycholic acids, are employed for gallstone therapy there are several dietary influences on the enterohepatic circulation of bile acids and on bile acid excretion (e.g. fats and dietary fibers) increased colonic bile acid concentrations have been implicated in the promotion of colorectal cancer and there appears to be an inverse relationship between cholesterolemia and colon cancer. 

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