March is national colon cancer awareness month. Colorectal cancer ranks as the third most common cancer in North America and the third leading cause of cancer death. Despite the fact that colorectal cancer is one of the most common cancers in western countries, it is also one of the most preventable ones.
Prevention is largely achievable through diet, lifestyle factors (such as exercise and smoking avoidance), dietary supplements and appropriate screening (such as colonoscopy).
Of these, diet appears to be the biggest single determinant of colorectal cancer risk, with up to 80% of colorectal cancers attributable to diet alone!
How can you keep your colon healthy and cancer-free? Here are five dietary factors with big impact:
Reduce animal foods in your diet, especially meat. A Harvard study found the risk of colon cancer was 2.5 times higher in women who ate beef, pork or lamb as a main dish every day compared to those eating it less than once a month. One of the culprits is a cancer-causing (carcinogenic) compound known as heterocyclic amines, formed when meat is cooked. Nitrosamines, a carcinogen especially high in processed and smoked meats, alter the DNA of colon cells and increase the potential for cancer cells to develop.
Increase your vegetable and fibre intake. In general, the risk for all cancers is twice as high in individuals with low vegetable, fruit and fibre intake. In colorectal cancer, research has shown those with higher intakes of dietary fibre, coupled with high intake of vegetables, have a significantly lower risk of colorectal cancer. Fibre helps bind and move toxic and carcinogenic compounds through the intestines faster, decreasing the time that these compounds contact the intestinal wall. It also acts as a pre-biotic, supporting the growth of healthy bacteria in gut. A diet high in fibre seems to be particular helpful for those who have or are prone to forming polyps in the colon - which is a significant and independent risk factor for colon cancer. Just how much fibre is enough? Based on scientific findings, 25 grams of fibre daily is the magic number.
3. Reduce your dairy consumption. In 2006, Harvard University published results of a large-scale research review they conducted to assess the relationship between dairy consumption and cancer risk. It found an overwhelming association with dairy consumption and higher rates of cancer, believed largely to be due to the concentrated hormones (namely estrogens) in milk. These findings were supported by another study published by Harvard in 2012 showing that pasteurized milk products from factory farms is linked to causing hormone-dependent cancers. Based on this research, Harvard researchers suggest getting your calcium from nuts, beans, fish, green, leafy vegetables and fortified milk alternatives (such as almond or soy milk).
Keep alcohol to a minimum. Recent studies have shown that alcohol consumption increases the risk of colorectal cancer, as well as other cancers such as breast, liver and pancreatic. The worst culprit for colon cancer is beer due to its high content of nitrosamines. Despite common beliefs that one to two glasses of wine per day promotes good health, the tannins found in red wine are potentially carcinogenic. Wine is easily converted to sugar, which is associated with higher levels of cancer-promoting inflammation. While resveratrol, found in high concentration in the skin of grapes, is an antioxidant with cancer-protective properties, you're better off to have some grapes instead of a glass of wine to get your dose of resveratrol. Those who consume little to no alcohol have a lower risk of colon cancer - and all cancers for that matter. While a glass of wine per day does seem to be good for the heart, it increases the risk for cancer.
Consume healthy fats, especially omega 3. Fish is the one exception to the rule that animal fats are bad. A Harvard study found those who consume fish have a lower incidence of colorectal cancer. Studies have found omega 3 fatty acids in particular are responsible for the protective effect. Wild salmon is the best choice, since it contains the least amount of mercury, dioxins and other toxic contaminants. The rest of your dietary fats should come primarily from plant sources of omega 3 and omega 6, such as pumpkin seed, flax seed, olive oil, hemp seed, grape seed oil, coconut oil (a healthy saturated fat), sunflower and sesame.
- Sharon Gurm is a naturopathic physician and founder of Port Moody Naturopathic Health and Wellness (www.portmoodynaturopathic.com). Follow on Twitter @drgurm.
