When we talk about nutrition and health, macronutrients (i.e., fats, carbohydrates, and proteins) typically get most of the attention, leaving most of the public unfamiliar with many of the smaller essential nutrients known as micronutrients. Micronutrients refer to our vitamins and minerals. These differ from macronutrients in that they are required by the body in smaller quantities than macronutrients. They are, however, just as important because they are essential for a large variety of bodily functions.
You may be familiar with some of the major minerals such as calcium, sodium, potassium, etc., but selenium may be one you haven’t heard too much about. Selenium is one of the nine essential trace minerals, meaning that it is needed in even smaller amounts than our major minerals. But don’t let its small requirement fool you! Selenium has many important roles in the body.
Functions of Selenium
The primary function of selenium is to act as an antioxidant, meaning that it can help to protect body cells and tissues from damage caused by free radicals. These free radicals are formed continuously from normal body functions such as metabolism and immune system responses, or lifestyle activities such as smoking and alcohol consumption. If the body is deficient in antioxidants such as selenium for long periods of time, these free radicals can build up and cause progressive damage to cells and tissues.
Selenium is also involved with other protective functions in the body such as DNA repair, and programmed cell death (apoptosis). Selenium assists in DNA repair by helping to increase the activity of DNA repair enzymes, which can prevent fatal cell damage and potential mutations. Apoptosis is a function that sounds seemingly bad at first, but is actually very important in the body to destroy and ultimately replace abnormal, dysfunctional, or infected cells. This helps to prevent disease and keep the body healthy.
Potential Health Benefits of Selenium
Due to these functions, selenium is linked to a large variety of health benefits when consumed adequately through your regular diet. Some of these potential benefits include:
Cancer prevention. Cancer is primarily caused by damage to DNA within cells that results in genetic mutations. By preventing DNA damage, assisting in the repair of DNA, and assisting in apoptosis, selenium can help prevent and slow the spread of cancer. The benefits on selenium have been reported in a number of cancers including colorectal, prostate, lung, bladder, skin, esophageal, ovarian, and stomach cancers.
Reduces risk for heart disease. Selenium is protective against heart disease mostly due to its antioxidant effects, which can protect the heart and blood vessels from inflammation, damage, and dysfunction.
Reduces risk for thyroid disease. The thyroid gland is vital for normal metabolism and growth and development. Selenium is more concentrated in the thyroid than in any other organ in the body and an association has been found between healthy selenium levels and decreased risk of thyroid damage, especially in women.
Improves fertility and protects against birth-related issues. Selenium is vital for the metabolism of certain sex hormones like testosterone, and in the production of healthy sperm and ovarian follicles. Selenium also helps to protect reproductive organs against inflammation and damage caused by oxidation.
Are You Getting Enough Selenium?
Optimal selenium intake is different based on factors such as age, pregnancy, and lactation. The best natural sources of selenium are Brazil nuts, seafood, meats, poultry, and organ meats. However, moderate amounts of selenium can also be found in many dairy products, cereals, and grains. It is recommended that people try to get most, if not all, of their daily selenium from food. Selenium supplements may be approved by a dietitian or physician if necessary. Specific conditions that may warrant selenium supplementation include HIV and hemodialysis.
However, selenium supplementation for most individuals is generally not recommended because of the possible health risks of excessive intake. Supplements generally contain very concentrated amounts of selenium, and if selenium supplements are taken on a regular basis for a long period of time, this may result in toxicity. Indicators of excessive selenium intake are:
Garlic odor on breath
Metallic taste
Nail/hair brittleness or loss
Nausea
Vomiting
Overall, selenium is an essential trace mineral with a large variety of health benefits if consumed adequately through the diet. Selenium is also beneficial for many individuals who are at risk for or have certain chronic diseases such as heart disease, thyroid disease, and certain cancers. It is best to always consult with your dietitian if you suspect that you may be deficient in selenium or if you plan on starting selenium supplementation.
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Written by: Dustin Hoenig, Wellness Workdays Dietetic Intern
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