Insulin Resistance & Colon Cancer

A rich diet, high in fatty animal products and refined carbohydrates, particularly when combined with a sedentary lifestyle, is known to promote insulin resistance in many people. This results in elevated levels of insulin in the blood. It has been proposed that high levels of insulin may be promoting the development and growth of colorectal cancers.1 A recent prospective study of 75,000 plus Norwegian men and women found that men who were more active in their leisure time were nearly half as likely to develop colorectal cancer during the ensuing 12 years. Increased activity has been consistently shown to reduce insulin resistance and lower blood insulin levels. This same study found women with elevated blood sugar levels after meals were about twice as likely to develop colorectal cancer as women with lower blood sugar levels.2

Elevated blood sugar levels after meals is usually due to insulin resistance and higher levels of insulin in the blood. The results of this study are consistent with the theory that insulin resistance and elevated insulin levels may play a role in promoting the development of colorectal cancers.A six-year prospective study of 32,000 plus Seventh Day Adventists found a nearly doubling of the risk of colorectal cancer in those who ate the most meat. By contrast those who ate a more vegetarian diet, with more legumes replacing meat, were much less likely to develop colorectal cancers. The authors of this study stated, “A complex relation was identified whereby subjects exhibiting a high red meat intake, a low legume intake, and a high body mass experienced a more than 3-fold elevation in risk relative to all other patterns based on these variables.”3People concerned about developing colorectal cancer can probably reduce their risk by cutting back on red meats (particularly processed and cured meats). These should be replaced with legumes (dried beans and peas), soyfoods and seafood. Regular exercise and limiting foods high in refined grains and sugars and consuming more fruits, vegetables and whole grains should aid weight loss, reduce insulin resistance and lower blood insulin levels. These diet and lifestyle changes will likely reduce the risk of developing colorectal cancer, diabetes, heart disease and strokes. 1. Cancer Causes Control 1995;6:164-792. Br J Cancer 2001;84:417-223. Am J Epidemiol 1998;148:761-74