For my second article on minerals I selected selenium. I mentioned selenium in #189 last October as one of the anti-oxidants in a study that improved many of the risk factors of heart disease.
Selenium is an essential trace mineral which means it is essential to good health but required in small amounts. It functions in the body as a component of certain antioxidants such as glutathione peroxidase (arguably our body’s most important antioxidant), which protects our cell membranes from free radical damage, reduces the risk of cancer and heart disease, and plays a role in thyroid function and in our immune system.
Population studies show that a lower intake of selenium is associated with a higher incidence of several cancers and some other diseases, but controlled clinical trials have been less clear. One large study by the U of Arizona in the 1980s found a 50% reduction of total cancer deaths in those taking 200mcg of selenium. While not considered deficient, most of the participants were in the low end of the normal range. Other studies have had mixed results, so the scientific consensus is that selenium supplementation only benefits people with a deficiency of the mineral, which is rare in North America.
People with inflammatory bowel conditions such as Crohn’s and ulcerative colitis, or people taking a proton pump inhibitor could be deficient in selenium. Ask your doctor for a blood test to find out. But be careful with selenium supplementation – it is toxic in high doses. Selenium also may interact with niacin, antacids, chemotherapy drugs, statin drugs, corticosteroids and birth control pills.
Health Canada’s RDA is 55 mcg for teens and adults with an upper limit of 400 mcg. Most people can obtain sufficient selenium from a healthy diet. Foods rich in selenium include nuts (especially Brazil nuts), seafood, meat and whole grains. Selenium supplements in Canada are sold in 50 to 200 mcg sizes. An average Brazil nut contains 70 mcg of selenium so eating one or two nuts a day would be a healthier choice if you want to ensure you are getting enough.
NIH Dietary Supplements
For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.