The compounds prevented both precancerous cell growth and tumor growth in the animals after they had received a compound known to induce colorectal cancer. Observational and experimental studies have suggested that dietary supplementation with selenium can inhibit the development of colon cancer. Patients in that study 200 micrograms of the trace element form of selenium per day for a mean of 4.5 years without toxic effects. Those researchers noted that the selenium dose of 200 micrograms per day is within the normal dietary intake of Americans and provides approximately twice the projected typical dietary intake of the study patients. Researchers are not sure how to explain the apparent anti-carcinogenic properties of selenium.
Selenium is an essential nutrient that help metabolize vitamin E and ensure optimal liver function.
Disease associated with selenium deficiency are rare in humans but can include heart failure and severe arthritis. While further studies are needed to determine the safety and efficacy of various selenium compounds in humans, these compounds could someday prove useful in the prevention of cancer, notes Dr. Karam El-Bayoumy, chief of division of cancer etiology and prevention, American Health Foundation.