We're sure you will agree that colon polyps aren't exactly a popular topic of conversation. However, because they increase our risk of colon cancer (and over 35% of those eating the typical American diet have polyps) it's important for us to discuss them. Notice in the above graph from Dr. T. Colin Campbell's China Study, how the incidence of cancer correlates to the amount of animal products consumed. As the grams of meat consumed rises, so does the incidence of colon cancer. Countries that consume the fewest animal products have very little incidence.
A widely held view in the medical community places the emphasis on routine colonoscopies as the exclusive means of preventing colon cancer. This creates a passive role for the patient. Although this early detection procedure locates and removes polyps that could potentially turn into cancer, we are not powerless in protecting ourselves from cancer. Many types of cancer are lifestyle related. By choosing to be pro-active, we can reduce our chances of developing polyps by modifying our lifestyle habits. For example, food is the most powerful tool we can use to inhibit the progression of cancer. The typical American diet promotes cancer growth, whereas the phytonutrients in a whole-food, plant-based diet offers powerful protection against cancer (especially a diet rich in cruciferous vegetables). For this reason, every meal we consume either encourages or discourages cancer cells from multiplying.
It's important for us to realize that we all have cancer cells inside of our bodies. We are also exposed to many carcinogenic agents on a daily basis, many of which come from our food. While genes and family history play a small role (1-3%) in the initiation of cancer, Dr. T. Colin Campbell's extensive research revealed how our everyday lifestyle choices can influence the expression of these genes by either turning them "on" or turning them "off." (See the below link.) What we are more likely to "inherit" from our family involves our food preferences and lifestyle habits. Therefore, parents who consume a rich, cancer-promoting, high-fat, nutrient and fiber-deficient diet teach their children to do the same. This has a tremendous impact on their children's risk for developing cancer.
Dr. John McDougall's article, Colon Polyps & Colon Cancer explains these concepts in greater detail. "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."
Many kinds of carcinogens found in the intestines are a result from the foods typically eaten in the American diet. These carcinogens have been shown to produce adenomatous polyps in animal studies. The foods which have been implicated in promoting cancer are: fats (especially beef fat), animal proteins, cholesterol, polyunsaturated vegetable fats, and sugar. Dr. McDougall adds that vegetable and fiber deficient diets also "adversely affect the colon lining and contribute to development and growth of polyps and cancers."
"The key to preventing recurrences of polyps" Dr. McDougall emphasizes, "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." Additionally, Dr. Neal Barnard states that polyps "become smaller and fewer in number within six months on a high-fiber diet."
For those patients who already have colon cancer, Dr. McDougall strongly urges for them to "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. 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."
It must be remembered though, that the benefits received by using a nutritional approach are directly proportional to the changes that are made. Making only small changes, while continuing to eat injurious foods will not offer any significant protection.
For more information regarding the association between animal-based diets and cancer, click on the following links: