What is it?
Selenium is one of the essential trace minerals required by the human body. It’s a nutrient with antioxidant properties which plays an important part in protecting cells against the effects of free radicals. The body has developed defences such as antioxidants to control levels of free radicals which damage cells and can contribute to a wide range of potential issues ranging in terms of skin health from acne and psoriasis through on a wider biological level to the development of some chronic diseases. Selenium is also essential for normal functioning of the immune system and thyroid gland, and can help lower the risk of joint inflammation. It’s therefore a nutrient which plays a very important role both in terms of your body functioning properly and as part of your skin care regime.
Where does it come from?
While the selenium content of food is highly variable because it depends so heavily on soil conditions, highly regarded sources of selenium include a variety of mushrooms, Brazil nuts, cod, tuna, halibut and calf's liver. Although the body doesn’t need huge amounts of selenium per day, the average "good" diet may contain only 35 to 60 mcg per day and many doctors advise taking 200 to 400 mcg per day for good health. Though a little is great, a lot can be toxic. However, excess intake is a rare problem in first world countries in which many people rely on diets rich in processed foods.
The role of Selenium
Although Selenium has a number of positive attributes in skin care, the key role relates to its antioxidant properties and ability to tackle free radicals. Free radicals are very unstable and react quickly with other compounds, generally attacking the nearest stable molecule, "stealing" its electron. When the "attacked" molecule loses its electron, it becomes a free radical itself, beginning a chain reaction. Once the process is started, it can cascade, finally resulting in the disruption of living cells such as skin cells.
Some free radicals arise as a normal product of metabolism and sometimes the body’s immune system’s cells purposefully create them to neutralise viruses and bacteria. However, environmental factors such as pollution, radiation, cigarette smoke and herbicides can also spawn free radicals.
Normally, the body can handle free radicals, but if antioxidants are unavailable, or if the free-radical production becomes excessive, cellular damage can occur. Of particular importance is that free radical damage accumulates with age. Antioxidants such as Selenium neutralise free radicals by donating one of their own electrons, ending the electron-"stealing" reaction. The antioxidant nutrients themselves don’t become free radicals by donating an electron because they are stable in either form. They basically act as scavengers, helping to prevent cell and tissue damage that could lead to cellular damage, and thereby helping to maintain the strength, health and elasticity of skin cells.
Selenium is indirectly responsible for keeping the body's supply of at least three other nutrients intact: these three other nutrients are vitamin C, glutathione, and vitamin E. Although the chemistry of these relationships is complicated, it centres around an enzyme (protein molecule in the body that helps "jump start" a chemical reaction) called glutathione peroxidase. This enzyme can’t function without selenium. Selenium also works synergistically with other antioxidants, in particular vitamin E, so together they provide an even stronger protection against free radical damage.