The mineral is a natural antioxidant that protects the cells against the oxidative damage of free radicals. Low selenium levels are associated with an increased risk for cancer in humans. Selenium supplementation might be useful in the prevention of cancer especially that of the respiratory and gastrointestinal tract. Selenium benefits all aspects of the immune system including the development and function of white blood cells. Selenium deficiency results in impaired immune system function and decreased resistance to infection.
Selenium offers beneficial protection against cardiovascular disease and strokes.
Selenium supplementation may also be helpful in patients with inflammatory conditions such as arthritis, eczema, and psoriasis. Due to its antioxidant properties, selenium may be protective against cataract formation. Low levels of selenium are linked to various conditions associated with free radical damage including premature aging, cardiovascular disease, cancer, and cataract formation. Chronically low dietary selenium is associated with an increased risk for cancer, heart disease, and low immune function. Severe selenium deficiency is associated with a heart disorder called Keshan disease.