The
discovery of selenium by the Swedish chemist J.J. Berzelius in 1817
initiated studies evaluating the influence of the inorganic forms of
this element on living organisms. Unexpectedly, in 1957,Schwartz and
Folz demonstrated the protective effect of selenium on organisms.
Many
foods include (grain products, seafood, meat and poultry) are major
sources of selenium. Seafood accounts for approximately 30% of the
dietary selenium intake.
Selenium is a mineral that works as an
antioxidant in the body. It can help to keep tissues healthy by
preventing cell damage. Selenium helps keep immune system and thyroid
working well. Selenium may help protect against the development of some
types of cancers and certain chronic diseases.
Drinking water has not been found to provide significant amounts of selenium in the diet.
The
good news is there are some good dietary sources of selenium:
Mushrooms, egg yolks, seafood, poultry and kidney, liver and muscle
meats contain the mineral. Vegetables -- garlic, onions, broccoli,
asparagus, tomatoes and others -- as well as whole grains and seeds can
also be good sources of selenium.
Cereal products make a major
contribution to intake because of the relatively large amount of them
consumed in most diet. Another good source of the element is nuts,
particular Brazil nuts.
Selenium content of foods can vary
considerably depending on the selenium content of the soil where the
animal was raised or the plant was grown. The selenium content of food
is largely dependent on the content of volcanic ash in the soil on which
the food was grown, with higher volcanic ash content yielding higher
selenium levels. Soil that is irrigated by seawater, such as much of
California's cropland, also contains higher levels of selenium.
Researchers
also know that soil in the high plains of northern Nebraska and the
Dakotas have very high levels of selenium. Selenium from natural food
sources has a higher bioavailability than functional foods or
nutraceutical and dietary supplements.
Selenium species include
organically bound forms such as selenomethionine, selenocysteine and
Se-methyl-selenocysteine as well as inorganic forms such as selenite and
selenate. For example, selenium in foods such as bread, cereals, nuts,
meat, fishand other seafood is found predominantly as the amino
acid derivatives, selenomethionine and selenocysteine.
Selenium in food
Arteries are crucial blood vessels in the circulatory system that play a
vital role in maintaining overall health and bodily functions. Their
primary funct...