Diet can promote or prevent colon cancer

Over 100,000 new cases of colon cancer occurred in the U.S. in 2009.[1]  Most colon cancer cases occur in people with no family history – genetics are thought to play only a small role in the development of colon cancer.  Colon cancer is most prevalent in Westernized societies, whose diets are higher in animal products and processed foods and lower in unrefined plant foods.  Epidemiological studies have suggested that diet is a key contributor to colon cancer risk.  The cells lining the intestinal tract come into direct contact with what we choose to eat – the substances contained in our food can therefore have profound effects on these cells and tissues.  The protective value of fruits and vegetables have been established by several prospective studies following subjects for years, keeping track of dietary patterns and colon cancer diagnoses.  Studies published in the past two years have attributed risk reductions up to 26% to high intakes of vegetables and fruits.[2]^,[3],[4]  However these modest benefits are mostly because dietary improvements were modest and the improvements were implemented later in life.  Earlier life intake of a diet rich in natural plant matter may offer more dramatic protection.  Data on cancer incidence in different populations suggests that a 20% increase in vegetable intake would result in a 20% decrease in cancer incidence in a particular population and a higher intake would beget even greater benefits.

Several food components that may modulate colon cancer risk have been identified – fiber, omega-3 and -6 fatty acids, and certain antioxidants, vitamins, and minerals all play a partial role, but the intake of thousands of unnamed phytochemicals have the most powerful benefits.  For those who wish to reduce their colon cancer risk, it is important to focus on the protective effects of whole foods – each vegetable and fruit contains thousands of micronutrients and phytochemicals, many of which work synergistically to exert their anti-cancer properties.  For example, fiber was considered to be a protective substance because of early epidemiological studies showing that diets high in fruits and vegetables were associated with decreased colon cancer risk.  But we realized it was all the features of high fiber natural foods, not the fiber itself that is important.  Later studies on fiber supplements showed no benefit[5], and it also seems that among the high fiber foods, vegetables, beans and fruits are far more protective than grains.[6]^,[7],[8]

Nutritious foods are very rich in fiber and disease-causing foods are generally fiber-deficient.  Red meat, processed meats are the most cancer causing, but all meats and dairy products do not contain any fiber, and are also lacking in anti-oxidants and phytochemicals.[9]  Foods made from refined grains (such as white bread, white rice, and pasta) are also not only fiber deficient but void of micronutrients and phytochemicals as well – these foods are also associated with colon and rectal cancers.[10]

At each meal, our food choices influence our future health.  Choosing a diet rich in nutrient dense plant foods like vegetables, fruits, beans, nuts, and seeds is a simple step we can take to protect ourselves against colon cancer.

Dr. Fuhrman is a best-selling author and board certified family physician specializing in lifestyle and nutritional medicine.  To learn more about Dr. Fuhrman, visit his website at DrFuhrman.com and blog at Diseaseproof.com.