Cofactors May Explain Why Some Get Colon Cancer, Others Don't

Although scientists are not sure what causes colon or rectal cancers, they know that they are associated with lack of exercise, eating too much meat, and the human wart virus (HPV). A study from Sendai, Japan shows that men who spend a lot of time walking are at reduced susceptibility to developing colon cancer.

An extensive review of the world's literature shows that colorectal cancer occurs far more frequently in prosperous industrialized countries, and that dietary factors may cause up to 75 percent of these cancers. You are increased risk for colon cancer if you are overweight, and exercise reduces your risk. Rectal cancer is not affected by obesity or exercise, and may be associated more with infection, such as with the HPV virus that causes genital warts. Since the vast majority of people who are infected with HPV do not get cancer, we have to explain why some do. The leading theory is that of cofactors: some combination of infectious agents, genetic susceptibility or lifestyle factors. I think that rectal cancer requires some kind of infection, but you do not develop the cancer unless you also smoke, lack vitamin D, eat a lot of meat, or some other combination of factors. Colon cancer appears to require some combination of factors such as lack of vitamin D, eating meat, not exercising or not eating enough foods from plants. Journal references; more on colon cancer