Selenium is actually a mineral, not an antioxidant. However, the benefits of selenium allow all the members of network antioxidants to perform functions that they could not do on their own. It's also an essential component of two important antioxidant enzymes that are manufactured by your body, glutathione peroxidase, which recycles glutathione; and thioredoxin, which recycles vitamin C.
There are two primary ways that selenium acts to prevent heart disease. First, it is needed for the body to manufacture the antioxidant enzyme glutathione peroxidase. This enzyme's principal job is to stop lipid peroxidation, especially in LDL cholesterol.
It's the oxidation of LDL cholesterol (the so-called bad cholesterol), not your blood level, that causes your arteries to clog. If you're getting a sufficient supply of selenium, along with the right antioxidants, this process will likely never happen.
Secondly, this trace mineral has a very complementary relationship with vitamin E, your body's primary fat-soluble antioxidant, and the vitamin most responsible for preventing heart disease. In combination, these two nutrients are even more powerful in their ability to prevent heart disease than either of them by themselves.
Selenium seems to protect against many types of cancers, including lung, prostate and colon cancer. There are numerous studies that have linked low levels in the body with higher rates of cancer. Much of the scientific literature on this trace mineral demonstrates its ability to accelerate the destruction of tumor cells.
The antioxidant network works together. Given what is known about the antioxidant network, it is unlikely that selenium alone is responsible for the reduction in cancer rates in these studies. More likely, it may be because it is necessary for the production of enzymes needed to produce glutathione, which in turn recycles vitamin C, which in turn recycles vitamin E. Together, the cancer protection is more powerful than any of its individual components could produce. This is yet another example of how the network antioxidants work together.
The use of this mineral during chemotherapy, in combination with vitamin A and vitamin E, has been shown to reduce the toxicity of chemotherapy drugs and help enhance the effectiveness of the chemotherapy while minimizing damage to the patient's normal cells.
Selenium is an important nutrient in the prevention of cataracts and macular degeneration. The primary cause of these diseases is lipid peroxidation in the eye. Blood profiles of people suffering from macular degeneration show low levels of selenium and glutathione, but high levels of oxidized glutathione.
AIDS patients all share a common link: they are extremely deficient in both glutathione and selenium. Low levels of these nutrients can place AIDS patients under extreme oxidative stress, which will only weaken their immune function further.
AIDS patients with the lowest levels of glutathione have the highest mortality rate. Supplementing with selenium, as well as alpha-lipoic acid and the amino acid N-acetyl-cysteine, is the best way to increase your level of glutathione.
Together with vitamin E, selenium strengthens your immune system,
thyroid, liver and pancreas. Together with zinc, it reduces enlarged
prostates and may offer some fertility benefits.
Selenium also binds very well with mercury, and can neutralize its toxic effects, especially in the brain.
In addition, this incredible little powerhouse has been shown to play a role in the prevention and/or treatment of the following diseases:
Although there are some good food sources of selenium, the concentration of selenium in soil varies by region, so the amounts you're getting in your food will vary depending on where it was grown or where the animals were raised. Discover which foods are the best source of selenium, see my page on selenium foods.
If you find it difficult including enough selenium-rich foods into your diet, it might be worthwhile to look into a selenium supplement. For more information on supplementing with selenium, go to my page on selenium supplements.
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