Selenium is a trace mineral that your body needs in small amounts.
Selenium helps the body with:
- Making special proteins, called antioxidant enzymes, which play a role in preventing cell damage
- Helping your body protect you after a vaccination
Some medical studies suggest that selenium may also help with the following conditions:
- Prevent certain cancers
- Prevent cardiovascular disease
- Help protect the body from the poisonous effects of heavy metals and other harmful substances (like chemo)
Plant foods, such as vegetables, are the most common dietary sources of selenium. How much selenium is in the vegetables you eat depends on how much of the mineral was in the soil where the plants grew. Grains and garlic are also good vegetarian sources of selenium. Brazil nuts are perhaps the richest dietary source of selenium; one ounce can contain as much as 10 times the adult USRDA. I usually get some raw Brazil nuts in bulk whenever I make a trip to the health food store and grab a few of them each day to munch on.
Selenium deficiency is rare in people in the United States. However, selenium deficiency may occur when a person is fed through a vein (IV line) for long periods of time.
Keshan disease is caused by a lack of selenium. This leads to an abnormality of the heart muscle. Keshan disease caused many childhood deaths in China until the link to selenium was discovered and selenium supplements were provided.
Two other diseases have been linked to selenium deficiency:
- Kashin-Beck disease, which results in joint and bone disease
- Myxedematous endemic cretinism, which results in mental retardation
Severe gastrointestinal disorders, like Crohn’s disease, may also affect the body’s ability to absorb selenium.
What are some current issues and controversies about selenium?
Selenium and cancer
Observational studies indicate that death from cancer, including lung, colorectal, and prostate cancers, is lower among people with higher blood levels or intake of selenium. In addition, the incidence of nonmelanoma skin cancer is significantly higher in areas of the United States with low soil selenium content. The effect of selenium supplementation on the recurrence of different types of skin cancers was studied in seven dermatology clinics in the U.S. from 1983 through the early 1990s. Taking a daily supplement containing 200 mcg of selenium did not affect recurrence of skin cancer, but significantly reduced the occurrence and death from total cancers. The incidence of prostate cancer, colorectal cancer, and lung cancer was notably lower in the group given selenium supplements.
Research suggests that selenium might affect cancer risk in two ways. As an anti-oxidant, selenium can help protect the body from damaging effects of free radicals. Selenium may also prevent or slow tumor growth. Certain breakdown products of selenium are believed to prevent tumor growth by enhancing immune cell activity and suppressing development of blood vessels to the tumor.
Selenium and heart disease
Some population surveys have suggested an association between lower antioxidant intake and a greater incidence of heart disease. Evidence also suggests that oxidative stress from free radicals, which are natural by-products of oxygen metabolism, may promote heart disease. For example, it is the oxidized form of low-density lipoproteins (LDL, often called “bad” cholesterol) that promotes plaque build-up in coronary arteries. Selenium is one of a group of antioxidants that may help limit the oxidation of LDL cholesterol and thereby help to prevent coronary artery disease. Currently there is insufficient evidence available to recommend selenium supplements for the prevention of coronary heart disease.
Selenium and arthritis
Surveys indicate that individuals with rheumatoid arthritis, a chronic disease that causes pain, stiffness, swelling, and loss of function in joints, have reduced selenium levels in their blood. In addition, some individuals with arthritis have a low selenium intake.
The body’s immune system naturally makes free radicals that can help destroy invading organisms and damaged tissue, but that can also harm healthy tissue. Selenium, as an antioxidant, may help to relieve symptoms of arthritis by controlling levels of free radicals. Current findings are considered preliminary, and further research is needed before selenium supplements can be recommended for individuals with arthritis.
Selenium and HIV
HIV/AIDS malabsorption can deplete levels of many nutrients, including selenium. Selenium deficiency is associated with decreased immune cell counts, increased disease progression, and high risk of death in the HIV/AIDS population. HIV/AIDS gradually destroys the immune system, and oxidative stress may contribute to further damage of immune cells. Antioxidant nutrients such as selenium help protect cells from oxidative stress, thus potentially slowing progression of the disease. Selenium also may be needed for the replication of the HIV virus, which could further deplete levels of selenium.
Ask your Doctor or health care professional if adding selenium to your diet is right for you. Be informed and be healthy!
Choosing healthy living over dying 🙂