Worldwide, polyps in the colon are found commonly in populations with a high incidence of colon cancer. Both are believed to share the same cause–the diet. Common sense would suggest that the contents of the colon–the remnants of foods a person has eaten–would be highest on the suspect list. Colon cancer is found most frequently in wealthy countries, where people eat rich foods consisting predominately of meats, poultry, fish, dairy products, vegetable oils, white bread and other refined grains, and highly processed foods. On the other hand, people following diets providing plentiful amounts of whole grains, vegetables, and fruits and with very little in the way of meats and dairy products, develop few cases of colon cancer. When people move from a country of low incidence to a country of high incidence their risk of developing colon cancer increases as they adopt the richer kinds of foods. This correlation shows the importance of environment, rather than of genetics, in the epidemiology of colon cancer.
In animal studies cancer-causing chemicals, known as carcinogens, produce adenomatous polyps and colon cancers that seem to be identical to those present in human beings. Many kinds of carcinogens found in the intestinal contents result from eating the foods found in the American diet. Fats, especially beef fat, are degraded to yield cancer-causing substances in the colon. Other components of a diet that is high in animal proteins, cholesterol, polyunsaturated vegetable fats, and sugar, while being low in vegetables and fibers also adversely affect the colon lining and contribute to development and growth of polyps and cancers.
The key to preventing recurrences of polyps is to improve the contents of the colon by making a change in diet. Changing to a low fat, no cholesterol diet rapidly and dramatically reduces the total amount of carcinogens released in the colon; an increase in fibers dilutes the few dangerous substances that do remain and shields the colon from their harmful effects; and an increase in vegetables–especially broccoli, cauliflower, Brussels sprouts, turnips, and leafy greens–causes the colon’s cells to secrete enzymes that inactivate many carcinogens.
Surgical operations that divert the flow of feces away from the segment of the colon where polyps have formed have resulted in regression of the polyps. This finding clearly shows that polyps are reversible, and suggests that a stage in the transition of polyps toward the development of cancerous cells can be prevented. Studies should be made to determine if a low-fat, high-fiber diet–which is opposite to the one believed to be the cause of colon polyps and cancer–would result in similar regression.
Patients who already have colon cancer should seriously consider a change in diet as a major part of therapy. Animal experiments show that diets high in fat and cholesterol promote the growth of several kinds of cancers and they further demonstrate that low-fat, no cholesterol diets retard the growth of cancers and prolong the animal’s life.
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Recommendations
Prevent polyps and colon cancer with a starch-based diet. If large polyps do form, then of course have them removed. If a cancerous polyp or actual tumor is found, surgery should be limited to removal of the obvious cancer (Avoid blood transfusions because they impair the immune system and dramatically decrease chances of survival.) After polyps or cancer of the colon have developed, a health-promoting diet is very important: it may check or slow further progress of either condition, and, in doing so, prolong your survival.
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References
Frank, J. Occult-blood screening for colorectal carcinoma: the yield and the costs. Am J Prev Med 1:18, 1985
Chapuis, P. Predictive value of rectal bleeding in screening for rectal and sigmoid polyps. Br Med J 290:1546, 1985
Wegener, M. Colorectal adenomas. Distribution, incidence of malignant transformation, and rate of recurrence. Dis Colon Rectum 29:383, 1986
Correa, P. The epidemiology of colorectal polyps. Cancer 39:2258, 1977
Editorial–Questions about occult-blood screening for cancer. Lancet 1:22, 1986
Leffall, L. Surgical management of colorectal polyps. Cancer 34:940, 1974
Tornberg, S. Risks of Cancer of the Colon and Rectum in Relation to serum cholesterol and beta-lipoprotein. N Engl J Med. 315:1629, 1986
Bristol, J. Sugar, fat, and the risk of colorectal cancer. Br Med J 291:1467, 1985
Nauss, K. Dietary fat and fiber: relationship to calorie intake, body growth, and colon tumorigenesis. Am J Clin Nutr 45:243, 1987
Willaims, R. Multiple polyposis, polyp regression, and carcinoma of the colon. Am J Surg 112:846, 1966
DeCosse, J. Effect of wheat fiber and vitamins C and E on rectal polyps in patients with familial adenomatous polyposis. J Natl Cancer Inst 81:1290, 1989
Gingold, B. Local treatment (electrocoagulation) for carcinoma of the rectum in the elderly. J Am Geriatrics Society 29:10, 1981
Fielding, L. Red for danger: blood transfusion and colonrectal cancer. Br Med J 291:841, 1985
