Selenium - an important antioxidant

Selenium is an element with many functions in the body. Selenium acts as a strong antioxidant in its own right, but is also the main component of the body's own antioxidant enzyme, glutathione peroxidase. As an antioxidant, selenium is important for the breakdown of hydrogen peroxide and fatty acid peroxides, among others. When selenium breaks these down, it also prevents the formation of free radicals that otherwise contribute to ageing, for example. Selenium also enhances the effects of vitamin E and vitamin C, which are also important antioxidants.

The immune system depends on selenium

Selenium contributes to the functioning of the immune system in several ways. Selenium stimulates the production of antibodies, strengthens the function of T-cells and macrophages and increases the activity of the thymus (thymus gland) where T-cells mature. T-cells are part of the adaptive immune system that is formed in response to a specific pathogen. After infection, it takes about 1 week for the adaptive immune system to fully develop. Should we then encounter the same pathogen again, the T-cells recognise it and can act quickly and effectively.

Selenium deficiency

Selenium is found in both plant and animal foods in varying amounts. Some examples of foods that contain selenium are fish, seafood, eggs, butter, brown rice, nuts and seeds. According to the National Food Administration, adults consume an average of 40-50 µg of selenium per day, which is just below the recommended daily intake of 50-60 µg. This is largely due to the fact that foods no longer contain as much selenium as they used to. Soils are depleted and selenium-poor, which has reduced our selenium intake over time, particularly in Sweden. Selenium can usefully be taken as a supplement to the daily diet to ensure an adequate and optimal intake.

Selenium deficiency may also be linked to higher infectiousness and more negative disease outcomes in viral infections such as influenza.

Selenium for normal thyroid function

The thyroid gland is an organ that affects almost all functions of the body, but its most important task is to regulate the body's metabolism. The thyroid gland produces so-called thyroid hormones on the order of the hypothalamus in the brain, which detects when hormone levels in the blood drop. The hypothalamus then sends a signal to the pituitary gland, which in turn produces a hormone called TSH. TSH is sent to the thyroid gland and asks it to produce the prohormone T4 as well as the active thyroid hormone T3. To make T3, the thyroid gland depends on selenium. A large proportion of T4 is converted in the liver to T3 and then transported into the cells where the hormone regulates the cell's metabolism such as energy and heat production.