Quercetin and the Risk of Colorectal Cancer Agawam MA

Colorectal cancer, also called colon cancer or large bowel cancer or rectal cancer, includes cancerous growths in the colon, rectum and appendix. With 655,000 deaths worldwide per year, it is the third most common form of cancer and the second leading cause of cancer-related death in the Western world. In the United States, it is the fourth most common cancer in men and women. Caught early, it is often curable. It is more common in people over 50, and the risk increases with age. You are also more likely to get it if you have:

    ?   Polyps - growths inside the colon and rectum that may become cancerous
    ?   A diet that is high in fat
    ?   A family history or personal history of colorectal cancer
    ?   Ulcerative colitis or Crohn's disease

Many colorectal cancers are thought to arise from adenomatous polyps in the colon. These mushroom-shaped growths are usually benign, but some may develop into cancer over time. Symptoms can include blood in the stool, narrower stools, a change in bowel habits and general stomach discomfort. However, you may not have symptoms at first, so screening is important. Everyone who is 50 or older should be screened for colorectal cancer. Colonoscopy is one method that your doctor can use to screen for colorectal cancer. Treatments for colorectal cancer include surgery, chemotherapy, radiation or a combination of treatments.

Quercetin is one of a number of water-soluble plant pigments called bioflavonoids. Quercetin and the other bioflavonoids cannot be synthesized by humans. However, they reportedly exert a wide variety of biological effects when ingested. It has been shown to have anti-inflammatory and antioxidant properties, and is being investigated for a wide range of potential health benefits. Quercetin is found in many foods including apples, onions, tea, berries, grapes, broccoli, cauliflower, and cabbage, as well as many seeds and nuts.

A new study has found that increased intakes of the compound quercetin may reduce the risk of developing colon cancer by 50 percent. Researchers conducted a case-control study involving 264 people with confirmed colorectal cancer and 408 healthy, cancer-free controls. Using a food frequency questionnaire, researchers were able to calculate flavonoid intake. They determined that although no association was found between developing colorectal cancer and total daily flavonol intake, there was an inverse association between non-tea flavonol and colorectal cancer risk. When the researchers considered only flavonoids from non-tea sources and the specific site of the cancer, a significant protective effect was documented for non-tea flavonols, specifically, quercetin and colon cancer but there was no protective effect for rectal cancer. Therefore, the authors concluded that quercetin appears to reduce the risk of developing colon cancer.¹

¹ Kyle JA, Sharp L, Little J, et al. Dietary flavonoid intake and colorectal cancer: a case-control study. Br J Nutr. Sep2009.