Selenium is a trace mineral and functions primarily as a component of the antioxidant enzyme glutathione peroxidase, which works with Vitamin E in preventing free radical damage to cell membranes. A low level of selenium in the body is linked to a higher risk for cancer, cardiovascular disease, inflammatory diseases, and any other diseases or conditions associated with an increased risk for free radical damage including cataract formation and premature aging.
Selenium’s chief beneficial effects stem from its role as an antioxidant. Selenium is incorporated at the 4 biochemically active sites of the enzyme glutathione peroxidase, which assumes a critical role in protecting against free radical and oxidative damage. In addition to this important role, selenium appears to exert antioxidant activity on its own, and is involved in the production of thyroid hormone. Selenium is also an antagonist to heavy metals like lead, mercury, aluminum, arsenic and cadmium.