Selenium May Increase Diabetes Risk

If you take selenium pills, you may be increasing your chances of developing diabetes, according to a report from the Nutritional Prevention of Cancer (NPC) trial (Annals of Internal Medicine, August 2007). This study is the largest and longest available experimental study of selenium supplements and was done by randomly selecting people for either placebos or selenium and then checking to see who develops diabetes.

In 1973, researchers showed that selenium protects against oxidative damage, chemical reactions that damage cells and shorten life. However, there is a narrow margin between getting enough selenium to keep you healthy and taking too much. High levels of selenium bind to and damage many essential body proteins. In the United States, dietary levels of selenium are high so there is little chances of developing selenium deficiency. Furthermore, selenium can be toxic to humans at low doses. Symptoms of poisoning include loss of hair and nails, tiredness, nerve or liver damage, and as shown in this study, diabetes. Selenium over-dosage cause oxidants to be formed in the body. They block the body's ability to respond to insulin and can even damage the insulin-producing cells in the pancreas. We do not know definitely that selenium causes diabetes, but until more data is available, most authorities recommend that people not take selenium supplements unless they have been tested and shown to have a selenium deficiency. Assess your risk for diabetes; weekly newsletter