Colorectal Cancers

Colorectal cancer is a common cause of death in the U.S., and approximately 1 in 20 (5%) will be diagnosed with colorectal cancer in their lifetime.¹ You may not know you have colorectal cancer until it has progressed, which is why screening has been suggested over the years as a useful strategy to lower death risk from this disease. If there are any of the following signs or symptoms, you may want to talk to your doctor:

• Anemia
• Severe constipation or obstruction
• Abdominal pain
• Blood in your stool
• Fatigue
• Unexplained weight loss

All cancers have causes that are multifactorial, but they are not inevitable and not the normal consequence of aging. One’s diet is the major factor increasing one’s risk or decreasing one’s risk of colon cancer. A systematic analysis by scientists of the World Cancer Research Fund reviewing over 1000 studies on bowel cancer risk has confirmed that red meat increases risk and high fiber plant foods decrease the risk. This strengthens WCRF/AICR’s* recommendation for people to consume a plant-based diet including whole grains, fruits, vegetables, and beans.

A small percentage of people who develop colorectal cancers had a genetic or inflammatory condition that was related to their elevated risk, however, scientific findings indicate that there are many factors that can lower the risk of developing colorectal cancer. Alcohol use, tobacco use, being overweight, being sedentary, eating meats (especially processed meats), and eating a low fiber diet have all been associated with a higher risk of colorectal cancer. Dietary factors can be significant when added all together. Cooking meats and processed meats at high temperatures, such as with grilling, broiling, or frying, increases risk, and when combined with very low fiber intake from vegetables, fruits, legumes, and whole grains, this can be synergistic at raising risk. Protective nutrients from these same high fiber plant foods may be actively working against cancer from developing, and an emphasis on the foods with the most protective nutrients is the best strategy.

Diet

• Many plant foods have been found to contain cancer-fighting nutrients, which can be eaten regularly for prevention or as part of a treatment regimen for colorectal cancer. Of the foods studied, the following has shown the most convincing evidence for protection.
  • Seeds—Seeds are high in fiber and have anti-inflammatory properties, which lower risk.
  • Green vegetables, particularly cruciferous vegetables (such as broccoli, kale, cabbage, and collards)—Cruciferous vegetables contain high amounts of special sulfur-containing compounds that fight cancer and have been shown to reduce the risk of colorectal cancer.¹
  • Garlic and onions—Similar to cruciferous vegetables, garlic and onions have special sulphur-containing compounds that help fight cancer.
  • Legumes (beans, lentils)—Eating beans and lentils, which are high in fiber and other protective nutrients, has been shown to be protective against colorectal cancer.² Fiber is especially protective in the colon, in part because gut bacteria break down fiber (and resistant starch) into short-chain fatty acids which have anti-cancer effects.^{3, 4}
  • Mushrooms—Mushrooms are helpful at reducing cancer risk, likely related to their beta-glucan content, which has anti-cancer effects.  They also contain inhibitors of cancer growth. 
  • Berries—Eating berries (strawberries, blackberries, cranberries, blueberries, etc.) have been shown to help fight cancer, likely related to their high fiber and flavonoid content.
• Tip: Onion family and cruciferous family vegetables are best eaten raw and chewed very well, or at least chopped finely or blended prior to cooking, in order to provide the strongest cancer protection.
• Reducing foods that are associated with higher risk, such as processed foods and animal products, is also an important strategy in reducing colon cancer risk. Red and processed meats in particular promote colorectal cancers, in part due to dietary carcinogens, such as heterocyclic amines and N-nitroso compounds.³
• Meal plan: Anti-cancer/High micronutrient, reduced in animal products and processed foods.

Supplements

• Dr. Fuhrman’s general supplement protocol for adults (see Vitamin Advisor for details) includes:

  • Multivitamin (without beta-carotene, vitamin A, vitamin E, folic acid, copper), such as Women’s Daily Formula +D3, Men’s Daily Formula +D3, or Gentle Care Formula.
  • Omega-3 DHA and EPA, such as DHA+EPA Purity.
  • Optional: Consider adding a mixed mushroom immune supplement, such as Immune Biotect, because of the potential immune system benefits throughout life from assorted mushroom phytochemicals not normally consumed in the diet.
• Additional supplements:
  • Green tea has anti-cancer effects in vitro, drinking green tea regularly is associated with a lower risk of cancer, and studies suggest that green tea supplements may help to reduce cancer-related biomarkers.⁵
  • Turmeric/curcumin: Curcuminoids, the widely studied bioactive components of turmeric, have anti-cancer effects in vitro, and human studies suggest beneficial antioxidant and anti-inflammatory effects.^{6, 7}
  • Grape seed extract has anti-cancer effect in vitro, such as inhibiting inflammation, proliferation, angiogenesis, and aromatase activity.⁸ Clinical trials are being conducted to find out whether grape seed extract is helpful for people with cancer or at high risk of cancer. 
  • Ultra Cell Biotect provides absorption-enhanced curcumin and green tea extract plus turmeric, grape seed extract, and black turmeric extract to help neutralize free radicals and promote cellular health. Consult your physician if you are on medication.
  • Mushroom extracts: Studies suggest that concentrated mushroom extracts may be a useful addition to cancer treatment, to decrease the immunosuppressive effects of chemotherapy.⁹
  • Immune Biotect provides assorted immune-supporting mushroom phytochemicals that are not normally consumed in the diet, plus astragalus, elderberry and other berry extracts. Consult your physician if you are on medication. 
  • Read more: Do you have a supplement formulated to enhance protection against cancer?

Exercise

Regular physical activity is associated with lower risk of colorectal cancer.

Read

Eat for Life

Super Immunity

Position Paper: IGF-1, Dietary Protein and Cancer

Learn

Sign up for the online Combat Autoimmune Disease and Cancer Masterclass

Other Considerations

• Screening is recommended. Screening methods such as colonoscopy, stool occult blood testing, and/or other methods are options for screening for colorectal cancers. Method and frequency should be discussed with your doctor and may depend on your medical history, family history, age, dietary pattern and prior screening test results.

• Weight loss: Obesity increases the risk of several cancers, including cancers of the colon and rectum.¹¹ Obesity is also associated with poorer prognosis in colorectal cancers.¹² If you are overweight or obese, a Nutritarian diet style will help you reach your ideal weight.