About 50 percent of colorectal cancer, the third most common cancer among men and women in the U.S., can be warded off through daily diet, physical activity and weight management, making it one of our most preventable cancers.
Five specific steps toward that goal come from an evidence-based report on reducing risk of colorectal cancer released recently by the American Institute for Cancer Research and World Cancer Research Fund as part of their Continuous Update Project (CUP). Here are those strategies, as well as some steps likely to offer additional protection:
1. Fill up on foods with fiber: Each 10 grams of dietary fiber is linked with a 10 percent lower risk of colorectal cancer, according to an analysis detailed two years ago in the British Medical Journal. Whole grains stand out as particularly linked to lower risk. Fiber adds bulk and reduces the time your digestive tract is exposed to carcinogens. Also, high-fiber diets encourage growth of health-promoting types of bacteria – trillions of which live in your gut.
• Focus on whole plant foods – vegetables, fruits, whole grains, beans, and nuts – in order to reach levels of fiber linked with lowest risk. Although you can get some of these benefits from fiber supplements or refined grains with added fiber, whole plant foods provide fiber along with protective nutrients and phytochemicals.
• Add beans or tofu to soups, stews and stir-fries.
• Start eating whole grain bread and pasta, then expand to a variety of unprocessed, cooked grains, such as bulgur, whole wheat couscous, quinoa and whole-grain polenta.
• Add some nuts or seeds – including ground flaxseed – to your morning cereal or smoothie.
2. Cut calories if you’re overweight: Especially if it’s around your waist. Excess body fat secretes inflammation-inducing proteins and creates cancer-promoting changes in hormones like insulin and growth factors. Each one-unit increase in body mass index (BMI), which corresponds to five to seven pounds for most adults, is linked with a 2 percent increase in colorectal cancer risk. Fat deep in the abdomen poses the most risk. Each one-inch increase in waist links to a 5 percent increase in colon cancer risk. The key: don’t simply add healthy foods; swap them for less healthy foods to boost nutrition and keep calories the same or lower.
• Sip water, seltzer, tea or coffee instead of soda or sugary tea and coffee specialty drinks.
• If you’re not hungry, relax with a walk, meditation, music or a book instead of food.
• If you drink alcohol, limit it to no more than one (for women) or two (for men) drinks a day. Alcohol is metabolized to compounds that damage cells and can lead to cancer.
• Watch your glass size. With today’s larger glasses, what you may consider one drink may be more.
• Choose seltzer flavored with fruit essence, or add slices of fruit to club soda for a more enticing option than plain water.
3. Limit red meat: Including beef, lamb and pork, and avoid processed meat. Each 3½-ounce portion of red meat eaten daily increases colorectal cancer risk 17 percent, according to CUP analysis published in PLoS ONE in June, 2011. Processed meat is even more strongly linked with risk; each portion half that size eaten daily increases risk 18 percent. Recommendations include limiting red meat, even if lean, to no more than 18 ounces a week and to save processed meat for occasional consumption.
• By swapping a couple of fish or seafood meals per week for red meat, you reduce colon cancer risk while promoting overall health. Add a few more meatless meals to your week, making sure to include beans, lentils or some other source of protein.
4. Get moving: Even if you don’t lose weight, a little extra activity every day can stop or slow weight gain. What’s more, regular physical activity fights cancer development directly by reducing elevated insulin levels and reducing inflammation, regardless of weight. Each 30 minutes of daily recreational physical activity is linked with an 11 percent decrease in colorectal cancer risk.
• You needn’t get the recommended 30 minutes or more of daily physical activity all at once. See how many 10-minute blocks of movement you can include throughout your day.
• Get up just a little earlier and start the day with a 10-minute walk.
• Get off public transit one stop early, walk 10 minutes at lunch or between projects, head outside or turn on your favorite tunes and dance before or after dinner.
BEYOND THE 4 STEPS
While other lifestyle strategies may not have as much research support as our top four, some also show colon-cancer fighting potential, including:
• Garlic: This plant food contains allyl sulfur compounds that, in studies, inhibit colon tumor formation. Population studies tend to link regular garlic consumption with lower colorectal cancer risk (Annals of Oncology, April 2013).
• Milk and calcium: Consuming milk probably decreases colorectal cancer risk, according to a study in the January 2012 Annals of Oncology. Milk could be protective in multiple ways; calcium’s effects on controlling cell growth and reproduction appear significant.
• Vegetables and fruits: Eating more vegetables and fruits may modestly reduce colon cancer risk. Aim for variety to get the widest array of protective compounds. Include cruciferous vegetables that may intervene directly in cancer development (Food and Function, October 2011). Consume deep green, orange, and red vegetables and fruits for beta-carotene and other carotenoids linked with reduced risk of the adenomas (benign polyps) from which most colon cancer begins (Cancer Causes and Control, April 2013).