Selenium Definition

• Selenium is a trace element that the human body needs and normally gets from food, according to the National Cancer Institute.
  
  

Selenium-Rich Foods

• Foods that come from plants, including rice, wheat and Brazil nuts, are especially rich in selenium. Other top food sources are meat and seafood.
  
  

Cancer-Fighting Antioxidant

• Selenium is an antioxidant, which is a substance that may protect cells against molecules called free radicals. These can damage cells and may cause heart disease, cancer and other diseases, according to the U.S. National Library of Medicine.
  
  

Tumor Inhibitor

• Selenium may also prevent or slow tumor growth associated with cancer, reports the NIH.
  
  

Prostate Cancer Study

• The Selenium and Vitamin E Cancer Prevention Trial was discontinued in October 2008. The study showed that taking the supplements did not prevent prostate cancer.