Selenium – A Mineral that is too often overlooked
Selenium is a trace mineral which is essential to humans, animals and plants. It is a component of the enzyme glutathione peroxidase which catalyzes the breakdown of the family of free radicals known as hydroperoxides. In this manner, selenium is important in the protection of cell membranes from free radical (oxidant) damage. There is a functional interrelationship between Selenium and Vitamin E. Selenium helps protect against the toxicity of mercury cadmium and silver. Selenium deficiency is characterized by abnormal nail bed growth, growth retardation, muscle cramps, and heart enlargement. An average daily intake is about 50 micrograms to 200 micrograms. Seafood, red meat and whole grains are good food sources with fruits and vegetables containing smaller amounts of selenium. Se is transported to tissues by lipoproteins (VLDL and LDL cholesterol) and is taken up by the red blood cells, liver, spleen, nails, hair and tooth enamel. Se is important in thyroid hormone metabolism. Selenium is toxic at levels 20 to 30 times the normal requirement, giving it a large safety margin. Signs of toxic levels of selenium include hair and and nail loss, dental caries, dermatitis, peripheral neuropathy, irritability and fatigue.
What will be focused on in the rest of this article is the evidence suggesting that selenium is protective in certain cancers, heart disease and viral infections.
Harold D Foster PhD a professor of geography at the University of Victoria BC has brought world attention to the fact that countries in Africa with high selenium levels in the soil have very much reduced rates of HIV/AIDS compared with their neighbors. Much of the soils in sub Saharan Africa are selenium deficient whereas Senegal’s soils are derived from marine sediments and thus selenium rich. Senegal has a low prevalence rate of AIDs, much, much lower than the rest of Africa, at 0.5 % of the population. Finland. in 1984, made a decision to add Selenium to its fertilizers. Interestingly Finland has one half the rate of AIDS than its neighbours. In both Senegal and Finland, there does not seem to be any other significant difference in lifestyle factors from their neighbors. Intriguing. The difference seems to be the selenium that the population receives either through the soil (which then gets incorporated into food) or through supplementation of the food supply. A recent article in Annals of Internal Medicine
A disease affecting individuals who are selenium deficient and infected with Coxsackievirus causes a fatal heart disease and is found in high numbers in areas of China with unusually low levels of Selenium in the soil. The Chinese were able to eradicate Keshan’s disease by adding Selenium to fertilizers, animal feed and table salt. In this same area of China, not only has coxsackie viral disease dropped, but so has the incidence of hepatitis in selenium supplemented areas. Research at the University of Liverpool has also shown that selenium may be protective against poliomyelitis.
Selenium is known to increase the enzyme glutathione peroxidase and the production of interferon gamma and the immune system T helper cells.
It is also known that 200mcg of Selenium daily decreases the likelihood of new cancers developing in men with prostate cancer.
Interesting reading about Selenium and other nutrients in the supportive treatment of AIDS is available in the e book What Really Causes AIDS which can be downloaded for free at www.hdfoster.com.
The bottom line about Selenium is that 200mcg daily for viral infections, cancer protection and general immune system health can be considered safe and effective as part of an overall Self Care program.
Nicholls and Thomas Coxsackie virus infection in acute myocardial infarction. Lancet April 23 1977 pg 883