The lower part of your digestive system, also known as the large intestine, contains your colon and rectum. Aging, heredity, preexisting medical conditions, diet and lifestyle habits make this region susceptible to polyp formations that may produce cancerous cells of the colon, rectum or both. Supplemental alpha-tocopherol, the active form of vitamin E, may help reduce cancer risk; however, studies were ongoing at the time of publication, showing no conclusive evidence of effectiveness in reducing your risk of colon cancer development.
Inconclusive Evidence
A 2000 study conducted by "Cancer Causes and Control," postulated participants with a history of smoking may benefit from alpha-tocopherol and beta-carotene supplementation in reducing colon cancer risk. Although the beta-carotene did not show beneficial effect, the alpha-tocopherol in high daily doses of 50 mg did have a preventive effect. However, a 2006 study reported in the "International Journal of Cancer," using similar study participants with an additional factor of poor iron absorption, did not conclude alpha-tocopherol was beneficial in preventing onset of colon cancer. The various ongoing studies for alpha-tocopherol in cancer prevention show promise, but a determination of effectiveness is not conclusive for colon or colorectal cancer risk reduction, according to the American Cancer Society.
Alpha-Tocopherol Information
Vitamin E contains eight antioxidants but alpha-tocopherol is the only active one with nutritional significance that the human body both uses and maintains. The antioxidant properties of alpha-tocopherol diminish free radicals, which form in the body during metabolism or exposure to environmental toxins like pollution or smoking. Cancer can form from free radical-caused oxidative damage. Alpha-tocopherol is fat-soluble, so when the free radicals form, the vitamin intercepts the damaging effects and neutralizes the free radical, thus reducing cancer cell development. However, not enough evidence exists to declare supplemental use of alpha-tocopherol as a colon cancer preventative.
Dietary Intake
The daily recommended intake for alpha-tocopherol in adults is 15 mg. Aside from being a potential cancer preventative, this vitamin is essential to diet. Vitamin E plays a role in building red blood cells, protecting your immune system and in healing wounds. You can get vitamin E from foods like almonds, bran cereal, whole grains or sunflower oil. It stores in your body since it is fat-soluble. Supplementation is rarely necessary unless your physician advises use for medical purposes.
Precautions
Consumption of alpha-tocopherol in high doses from foods is not commonly associated with adverse effects; yet, high intake of alpha-tocopherol beyond safe upper limits carries a risk of toxicity. Do not exceed a daily dosage of 1,000 mg without physician supervision. Side effects include hemorrhage and interactions with other medications.
References
- "International Journal of Cancer"; Iron and Colorectal Cancer Risk in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study; Amanda J. Cross, et al.; 2006
- "National Cancer Institute"; Selenium and Vitamin E Cancer Prevention Trial; February 2010
- American Cancer Society: Vitamin E
- "Linus Pauling Institute"; Vitamin E; Jane Higdon, Ph.D.; November 2004
- Stanford Medicine: Nutrition to Reduce Cancer Risk
- "Cancer Causes and Control"; Effects of Supplemental Alpha-Tocopherol and Beta-Carotene on Colorectal Cancer: Results From a Controlled Trial (Finland); D. Albanes, et al.; March 2000
