Selenium: too much of a good thing?

The micronutrient selenium is crucial for the antioxidant response, as well as for immune system and thyroid hormone regulation. Inadequate selenium intake, which affects one in seven people in the world, has been associated with increased risk of cancer, neurodegenerative diseases and thyroid dysfunction. This has led to empirical health advice recommending increasing selenium intake through diet or supplementation. As a result, selenium supplements have been widely consumed under the understanding that “the more the better”. Nonetheless, recent studies have indicated that high selenium consumption is associated with an increased risk of chronic diseases such as diabetes. This project aims to elucidate the link between selenium status and chronic diseases, as well as to provide insight on how much selenium is required for optimal health.