What is selenium?
Selenium is a trace mineral that is essential to good health but required only in small amounts [1, 2]. Selenium is incorporated into proteins to make selenoproteins, which are important antioxidant enzymes. The antioxidant properties of selenoproteins help prevent cellular damage from free radicals. Free radicals are natural by-products of oxygen metabolism that may contribute to the development of chronic diseases such as cancer and heart disease [2,3]. Other selenoproteins help regulate thyroid function and play a role in the immune system [4-7].
Stewart Eckard and Mike Darnofall Thanks to the University of North Carolina School of Pharmacy for the use of this article! Dietary Sources • Wheat germ (111) • Whole wheat bread (66) • Oats (56) • Turnips (27) • Brazil nuts (103) • Bran (63) • Brown rice (39) • Garlic (25) Deficiency • Keshan disease (heart) – China • Kashan-Beck disease (arthritis) – China • Increased risk of cancer, heart disease, and low immune function with chronic low intake of Se. Beneficial Effects • Anti-oxidant activity (Se-glutathione peroxidase) • Free radicals / strong oxidizers • Thyroid hormone production • Antagonistic to heavy metals (lead, mercury, cadmium, aluminum) Principal Uses Selenium works with vitamin E (tocopherol) in preventing free radical damage to cell membranes, proteins, and DNA Anti-Cancer • Low Se = increased cancer risk • Many cancer pts. have low blood levels of Se / glutathione peroxidase • Cancer preventive vs. antitumor effects • men > women • respiratory / GI cancers most signi
Selenium is a trace element that occurs naturally in the soil and is absorbed by plants and crops, from where it enters the human food chain – either directly or through consumption of meat and other products from grazing animals. However different regions have different levels of selenium in their soils. North American soil is naturally rich in selenium, meaning grains like wheat that are grown there have a higher content of the nutrient. Wheat grown in selenium-poor Europe, on the other hand, has lower selenium levels. Selenium may not have made as much of an impression on consumer consciousness as other minerals such as calcium, for instance, but the science has shown it plays an important role in health maintenance – and particularly in cancer prevention. It is included in between 50 and 100 different proteins in the body, with multifarious roles including building heart muscles and healthy sperm. Cancer prevention FDA has approved a qualified health claim for use with dietary supp
Selenium comes in several forms. It is known by the following names: selenium yeast, selenium sulfide, selenium acid, and sodium selenite. Only minute quantities of this mineral are needed, although the lack of it can cause many problems in the human body. The dietary sources for selenium are usually associated with the soil where they were grown. Vegetables and grain products often have a higher selenium content if the mineral was present in the soil from which they were harvested. Most meats and fish contain selenium, and are an excellent source of this mineral. Dairy products are also a good dietary source of selenium.
