Reduce Risk of Colorectal Cancer

a bowl of high-fiber oats

Colorectal cancer is the fourth most common cancer and the third leading cause of death from cancer, according to the National Cancer Institute. About 4 percent of the population will develop this form of cancer over the course of their lifetime. The five-year survival rate is 65 percent, but if caught in the earliest stages, the survival rate jumps to 90 percent.

Genetics account for only 5 to 10 percent of colorectal cases (and family history up to 25 percent), which means prevention tactics can greatly reduce your risk and improve outcomes.

Prevention comes in two forms: healthy habits for prevention and screening to catch cancer early while it’s most treatable. Ask your doctor if you’re eligible for a screening as well as the pros and cons of a colonoscopy versus at-home kits. Don’t put that off! In the meantime, incorporate healthy habits and useful supplements into your routine.

Ways to Help Prevent Colorectal Cancer

  • Keep Healthy Habits

    The best ways to prevent colorectal cancer are those that prevent and manage many other diseases, including other types of cancer. Exercise regularly, keep your blood sugar stable, don’t smoke, and limit your alcohol consumption.

  • Eat Foods High in Fiber

    Eat five or more servings daily of vegetables and fruit. Include naturally high-fiber foods such as nuts, seeds, whole grains (especially oatmeal), beans, legumes, apples, and pears.

    Ground flax, psyllium, chia, hemp seeds, bran, and other fiber supplements can be helpful, but food sources are best. Fiber keeps stool soft and moving through, improves blood sugar stability, feeds supports healthy (and anti-cancer) gut flora, and improves the body’s ability to detoxify.

    Reducing fat in the diet encourages more favorable gut flora and compounds like butyrate that discourage cancer formation.

    Microbiota (gut flora) love chewing on fiber. If you don’t consume enough fiber, they turn to an alternate food source – your protective mucin gut lining!

    While fiber in the diet is the most important, additional support may be found from prebiotic inulin, other complex polysaccharides, mucilaginous herbs like marshmallow and aloe inner gel, and probiotics such as Bifidobacterium longum.

    Incorporating more fiber into the diet can make you uncomfortably gassy. Try a slow introduction to give your gut flora a chance to adjust. If you haven’t adapted after a few months, ask your doctor to test you for small intestinal bacterial overgrowth (SIBO).

  • Consider Medicinal Mushrooms

    Mushrooms contain complex polysaccharides including glucans and beta glucan that help the immune system to better prevent and fight various types of cancer. In Asia, mushroom polysaccharide extracts are often prescribed as adjunct cancer treatments to improve outcomes.

    Turkey Tail

    The most human studies have been performed on turkey tail mushrooms, usually as an adjunct in cancer treatment to improve outcome and remission rates. Turkey tail extract kept colorectal cancer progression in check, decreased the voracity of cancer’s progression (how deep it went, how far it spread), and increased survival rate in colorectal cancer patients also receiving conventional care.

    Reishi and Shiitake

    A handful of studies show that reishi and shiitake extracts also inhibit colorectal cancer. To make the polysaccharides bioavailable, medicinal mushrooms should be cooked, heated, or simmered in water, even better if powdered first, or try extract capsules.

  • Healing Herbs and Supplements

    Drinking five or more cups of green tea daily may be helpful. EGCG in green tea inhibits cancer growth, induces cancer cell death, and inhibits the inflammation that fuels cancer.

    In one large study of nonsmoking men, each daily 2 gram intake of dry green tea leaves (about the amount in one tea bag) was associated with a 12 percent reduction in colorectal cancer risk.

    Turmeric powder in the diet or supplements may help prevent or fight various types of cancer including colon cancer through immune system support, deceased inflammation, and increased antioxidants. The spice and its constituents slow the promotion and progression of colon cancer and encourage cancer cell cycle arrest. One study suggested a dose of 3.6 grams of the constituent curcumin for colon care.

Click to See Our Sources

Anticancer: A New Way of Life by David Servan-Schreiber ($18, Penguin, 2017)

The Cancer-Fighting Kitchen by Rebecca Katz ($32.50, Ten Speed Press, 2017)

“Colorectal cancer prevention – patient version,” National Cancer Institute,, 3/15/19

“Consumption of the putative chemopreventive agent curcumin by cancer patients: Assessment of curcumin levels in the colorectum and their pharmacodynamics consequences” by G. Garcea et al., Cancer Epidemiol Biomarkers Prev, 1/05

“A dietary fiber-deprived gut microbiota degrades the colonic mucus barrier and enhances pathogen susceptibility” by M.S. Desai et al., Cell, 11/17/16

“Fiber, fat, and colorectal cancer: New insight into modifiable dietary risk factors” by S. Ocvirk et al., Curr Gastroenterol Rep, 12/2/19

“Green tea consumption and colorectal cancer risk: A report from the Shanghai Men’s Health Study” by G. Yang et al., Carcinogenesis, 11/11

“Key statistics for colorectal cancer,” American Cancer Society,, 1/8/20

“Protocol for minimizing the risk of metachronous adenomas of the colorectum with green tea extract (MIRACLE) . . .” by J.C. Stingl et al., BMC Cancer, 2011

Textbook of Naturopathic Integrative Oncology by Jody Noe ($99.95, CCNM Press, 2011)


Maria Noël Groves, RH (AHG)

Maria Noël Groves, RH (AHG), is the best-selling, award-winning author of Body into Balance: An Herbal Guide to Holistic Self Care and Grow Your Own Herbal Remedies.

Maria’s a registered professional herbalist with the American Herbalists Guild and a graduate of the Southwest School of Botanical Medicine and Rosemary Gladstar’s Sage Mountain.

Learn more about Maria and herbs at Wintergreen Botanicals.