Selenium is an antioxidant, meaning it helps prevent damage to cells and DNA by stopping free radicals, which in turn helps prevent cancer, reports LiveScience. Selenium may reduce the risk of cardiovascular disease, prevent memory loss and help thyroid problems.
Some studies support the idea that selenium reduces the risk of cancer, especially bladder and prostate cancer, reports LiveScience. Selenium plays an important role in the production of the thyroid hormone, and some studies found a link between selenium deficiency and thyroid goiters and damage.
Selenium may also benefit the heart by reducing inflammation and preventing platelets from grouping together, which lowers the risk of heart attack, states LiveScience. Selenium may also help stop mental decline in old age. Though there is not sufficient evidence to prove this claim, studies determined a person was more likely to experience cognitive decline when she had low selenium levels.