[Biological effects of selenium]

The role of selenium concerning its biological effects particularly in relation to cardiovascular and tumor diseases has been in the focus of intensive studies. Selenium is a constituent part of the enzyme glutathion peroxidase (E.C.1.11.1.9) which catalyzes the conversion of hydrogen peroxide and organic hydroperoxides into water and corresponding alcohols. A review of epidemiological studies is presented focusing predominantly on countries where a low concentration of selenium in blood serum was found. The role of selenium in the etiology of cardiovascular diseases may probably be accounted for by its protective effect as it prevents platelet aggregation and protects the arterial endothelium from being damaged by lipid peroxides. The results of experimental studies, carried out in research institutes in many parts of the world, suggest that coordinated supplementation of food with selenium may reduce the risk of cancer and moreover, the effect of selenium can be modified by other dietary factors, such as vitamin A and E. (Fig. 2, Ref. 29.)