Over 50,000 American men and women die every year from colorectal cancer (referred to in the rest of this column as colon cancer), but in some parts of the world it’s extremely rare because of differences in diet.

The lining of the colon, with its bumps and crevasses, has a large surface area that comes in contact with the food we eat. It’s not surprising, then, that what we eat has a strong influence on our risk for colon cancer.

The earliest stage of colon cancer is clusters of abnormal cells lining the colon. The second stage is polyps — small growths that protrude inward from the lining. The final stage occurs when these polyps gradually become malignant. Eventually, colon cancer extends through the wall of the colon and spreads (metastasizes) to other parts of the body.

Although the incidence of colon cancer rises with age, it is increasing in younger people — for reasons that are not completely clear. Early detection methods such as colonoscopy should be discussed with your primary care provider before you turn 45 — and earlier if you have a family history of polyps or colon cancer. If you and your provider decide on colonoscopy as a screening method, it’s usually less expensive in an outpatient facility instead of a hospital.

What a lot of people don’t know — including many health-care providers, most of whom don’t learn about disease prevention or nutrition in medical school — is that for the most part, colon cancer can be prevented. Following are some suggestions for colon cancer prevention from Dr. Michael Greger’s book “How Not to Die” and his website nutritionfacts.org; and from “The Cancer Survivor’s Guide” by Neal Barnard, M.D.:

· TURMERIC: Turmeric in curry is thought to contribute to the low incidence of colon cancer in India. Eat 1/4 to 1/2 teaspoonfuls a day, available in bulk at Natural Grocers in Glenwood Springs. When turmeric comes in contact with the lining of the colon, it prevents abnormal cells from forming, and if abnormal cells are already present, they revert to normal. Familial polyposis is a genetic disease in which family members develop multiple colon polyps, often resulting in colon cancer. When people with this condition are given daily turmeric, the number and size of polyps decreases by half. In one study advanced colon cancer resistant to chemotherapy and radiation regressed with oral or rectal (via enema) turmeric. Curcumin, a component of turmeric available in supplement form, is not as effective as whole, unprocessed turmeric.

· QUERCETIN is a plant nutrient that has been shown to decrease colon polyps and risk for colon cancer. It is found in foods such as grapes and red onions.

· FIBER: Eat high-fiber food, which means plant products (animals have bones that hold them up, plants have fiber). One of the properties of fiber that is thought to protect against colon cancer is that it decreases stool transit time — the time it takes for food to go through the intestinal tract. For example, food goes through men eating a plant-based diet in a day or two, but takes five or more days in men eating a conventional diet. Fiber also promotes a healthy gut microbiome, which helps protect against colon cancer.

· PHYTATES are another cancer-preventing plant nutrient, found in green leafy vegetables; legumes (beans, split peas, chickpeas, and lentils); whole grains; and nuts and seeds.

· EAT THE RAINBOW: Fruits and vegetables with intense color are loaded with antioxidants and other phyto (plant) nutrients which help prevent many health problems, including cancer. Examples are red onions, red cabbage, carrots, tomatoes, peppers, beets, sweet potatoes, berries, and dark red grapes. In one study daily intake of black raspberries for nine months reduced the number of polyps by half in patients with familial colon polyps.

· AVOID MEAT: This includes red meat, chicken and fish. These products increase the risk of colon cancer partly because they contain heme iron (plants contain non-heme iron), which causes free radicals, that contribute to inflammation and cancer. A six-year study of 30,000 people in California showed the risk of colon cancer doubled in those who ate read meat at least once a week, and tripled in those who ate chicken or fish at least once a week.

· AVOID PROCESSED FOOD, which lacks fiber and other health-promoting nutrients. This includes products such as cookies, cakes, pastries, doughnuts, chips, most brands of crackers, boxed cereals, and anything made from flour. (Dr. Greger says “if it’s a plant, eat it; if it’s made in a plant don’t”).

Dr. Feinsinger is a retired family physician with special interest in disease prevention and reversal through nutrition. Free services through Center For Prevention and The People’s Clinic include: one-hour consultations, shop-with-a-doc at Carbondale City Market and cooking classes. Call 970-379-5718 for appointment, or email gfeinsinger@comcast.net.