History of Selenium

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History of Selenium

 

 

Selenium is an essential trace element which is normally obtained

from

the diet. However, it was not until 1979 that it was recognized as a

requirement in human nutrition.

Previous to this time it was regarded as essential to animals only.

 

The first major breakthrough was achieved by Dr Klaus Schwartz who

discovered that liver necrosis in rats could be prevented with the

aid

of a kidney extract, found to contain selenium.

 

As a result of Schwartz' discovery, selenium became the object of an

intense programme of research, which continues today.

 

Researchers at Sian University in China in the 60's and 70's

experimented with selenium supplementation on sufferers from a heart

muscle disease which affected mainly young women and children. The

disease is now known as Keshan disease, Keshan being a province in

China

with the lowest selenium levels in the world.

 

Many people died of the disease, but with the aid of selenium

supplementation it has become more or less extinct.

 

In the 70's selenium deficient agricultural land presented serious

problems for the Finnish cattle industry, which were eradicated by

the

addition of selenium to fertilizers and cattle feed.

 

 

General Facts

Selenium has now been discovered to be part of the enzyme system

that

controls prostaglandins, which have widespread functions in the

body.

 

Studies on animals show that selenium reduces high blood pressure

and,

when combined with Vitamin E, reduces angina pectoris.

 

Selenium deficient animals do not reproduce and in fact half a man's

body stores of selenium are found in the testes and seminal glands.

 

Breast milk contains up to six times as much selenium as cow's milk

and

twice as much Vitamin E.

 

Australian researchers have linked selenium deficiency to cot

deaths.

 

 

Effects of Selenium

 

Selenium's contribution to the immune system is to protect the cells

against damage caused by oxygen-free radicals.

 

A free radical is an unstable highly volatile and incomplete

molecule

which is released as a by-product of the body's normal metabolic

processes, but which is highly destructive when present in excess

amounts.

 

Selenium is the principal mineral anti-oxidant and free radical

deactivator.

 

It combines with glutathione and Vitamin E to form gluathione

peroxidase, the body's free radical controller. Other factors

include

zinc, manganese and copper.

 

Prevention of infections and blood clots. It would appear that

selenium

increases the beneficial prostaglandins (a regulatory factor in the

coagulation of the blood) and decreases the formation of harmful

prostaglandins (eg prostaglandins causing inflammation in the

joints).

 

Low selenium levels are associated with ECG abnormalities indicative

of

heart problems.

 

Selenium prevents cancer. Selenium supplementation has been

effective in

the prevention of many, but not all, forms of cancer.

 

Selenium alone can give a 50% success rate, but combined with

vitamins

A & E this rises to a 90% success rate.

 

This incidence of cancer is more common in a sub-group of the

population

with low selenium blood levels.

 

As has already been seen, selenium protects cells from damage by

oxygen-free radicals. It also decreases the carcinogenic viruses and

inhibits the division of cancer cells.

 

 

The Link between Vitamin E and Selenium

 

Selenium is synergistic with Vitamin E, i.e. the beneficial effect

of

combined selenium and Vitamin E is greater that the added effect of

each

single nutrient.

 

The enzyme glutathione peroxidase requires both selenium and Vitamin

E

to function. The most efficient ratio is 100mcg Vitamin E to 25mcg

Selenium . (Selenium is 50-100 times more powerful than Vitamin E.)

 

 

Sources of Selenium

 

Good sources include fish, brazil nuts and organic liver. Whole

grains

and brown rice may also contain significant proportions, but levels

vary, depending on the soil content of the area in which they are

grown.

 

 

However, selenium is also lost in processing. Brown rice has fifteen

times higher levels than white rice and wholemeal organic bread has

twice the levels of white bread.

 

 

Groups at Risk from Selenium Deficiency

 

Young people who do not eat a balanced diet.

Vegetarians - in many cases a vegetarian's daily intake is as low as

10mcg a day - only a fraction more than the daily levels of victims

of

Keshan disease in China.

 

The elderly - often small meat eaters who do not eat enough to cover

their selenium requirement.

 

Pregnant and lactating mothers require much higher levels than is

usually ingested with the diet.

 

Smokers generally have lower selenium blood levels than non-smokers.

This may either be due to a non-absorption of selenium, or a greater

formation of free radicals.

 

The chronically ill - particularly where disease or medication

produce

loss of appetite, monotonous diets, diarrhoea and vomiting.

People living in areas of particularly low selenium levels in the

soil,

eg China, Scandinavia and Northern Europe.

 

 

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