Colorectal cancer obesity

Inter alia, the data suggest that protection against colorectal cancer is due to several mechanisms and that these can interact. One factor of considerable importance is the issue of overweight which is an independent risk factor for colorectal cancer. Obesity may have to be taken into account much more than has been the case in earlier studies. It appears that some of the effect may be mediated through raised plasma insulin and insulin-like growth factors (which may well be influenced by dietary carbohydrates). 

A prospective American Cancer Society study found an increase in the mortality rates for colorectal and prostate cancer in overweight men and for endometrial, gallbladder, cervical, ovarian and breast cancer in overweight women (Lew 1985). An association with obesity is now firmly established for breast cancer in post-menopausal women, as well as for endometrial cancer and for renal cell cancer. Obesity may also play a part in the pathogenesis of colorectal, prostatic and pancreatic cancers in men (Caroll 1998). 

In summary, the true association between most dietary factors and risk of colon cancer is unclear. The protective effects of fiber, calcium, and a diet low in fat are not completely known at this time. Lifestyle factors such as NSAID use and hormone replacement use appear to decrease the risk of colorectal cancer, but questions remain about how to best use these agents. Obesity and alcohol use appear to increase risk of colon cancer, but their association is not well defined. Genetic and clinical risk factors such as inflammatory bowel disease are weU known risks for colon cancer. 

Terry PD, Miller AB, Rohan TE. Obesity and colorectal cancer risk in women. Gut 2002 51 191-194. 

Johnson, I.T., and Lund, E.K., 2007. Review article nutrition, obesity and colorectal cancer. Alimentary Pharmacology Therapeutics. 26 161-181. 

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