Diet's influence on colorectal cancer

March is not only National Nutrition Month but also Colorectal Cancer Awareness Month. Colorectal cancer (cancer of the colon and rectum) is the second most commonly diagnosed cancer in the United States. Most colorectal cancers begin as benign adenomas or polyps that grow on the inner lining of the colon. These grow slowly and take anywhere from 10-20 years to become cancerous. This is why regular screenings are so important to identify and remove the polyps.

There is clear evidence of genetic predisposition to colon cancer, but the variation in diagnosis could be linked to dietary habits. The data from many epidemiological studies seems to suggest that increased vegetable consumption is associated with lower risk and lower meat consumption is associated with lower risk.

Johns Hopkins Colorectal Cancer Center recommends, eating plenty of brightly colored fruits and vegetables. These are packed with antioxidants which protect the colon’s cell walls, but also contain high amounts of dietary fiber. Fiber decreases fecal transit time and increases stool bulk. It also dilutes other colonic constituents which decrease contact between carcinogens and the colon’s cell walls. Fiber undergoes fermentation in the presence of colonic flora, which reduces fecal pH and generates short-chain fatty acids. Some of these fatty acids have a protective effect against the cell walls. And you thought you were just eating an orange!

Fiber recommendations

Sources of fiber include beans, peas, nuts, seeds and whole grain products. Here are the fiber recommendations for adults:

Age 50 and younger Age 51 and older

Men 38 grams 30 grams

Women 25 grams 21 grams

It’s not that we need less fiber in our diet as we age, but our calorie needs decrease, so consequently we get less fiber from our foods. Remember this important tip… every meal should include a fruit and/or vegetable. If you can make this a habit, sort of like brushing your teeth, you can be sure to get the recommended 5-9 servings of fruits and vegetables in every day.

Also include foods rich in omega-3 fatty acids 1-3 times per week, such as salmon and halibut, which have been linked to reducing the risk of colorectal cancer. Exercising regularly and maintaining a proper weight can also cut your risk of developing colorectal cancer. Any kind of exercise, even small amounts on a regular basis can help. The American Cancer Society recommends at least 30 minutes of physical activity on most days. Join me and other members of the North Idaho Cancer Coalition in spreading the word about screening and prevention. For more information on colorectal cancer, check out the Panhandle Health District’s website: http://www.phd1.idaho.gov/preventative/chronicdisease/cancer.cfm.