Discovered by a Swedish chemist in 1817, selenium became the subject of scientific interest in the 1950s. It is an essential trace element in the human body and contributes to the maintenance of various bodily functions.
Trace elements are minerals present in small amounts in living tissues. There are a total of 14 known trace elements including iron, zinc, iodine, copper, manganese, aluminum, lead and others. Selenium is not synthesized in the human body naturally and can only be procured through diet or supplement intake. Acting as a powerful antioxidant, it protects the human body from the damaging effects of free radicals and thus supports the body’s defenses.
Types of selenium
Selenium exists in two forms: inorganic and organic. The inorganic compounds are known as ‘selenate’ and ‘selenite’, while the organic compounds are known as ‘selenomethionine’ and ‘selenocysteine’. Plants usually contain an inorganic form that is converted to selenocysteine and can be used by the human body. The human body absorbs the mineral most readily when it is in the presence of fat-soluble vitamins such as A, D and E.
Dietary sources that are rich in selenium
- Seafood (oysters, tuna, sardines, crab, etc.)
- Meat (kidney, liver)
- Brazil nuts
The best way to take selenium is through a diet that is rich in this important mineral. However, in some cases it may be necessary to resort to supplemental selenium intake through dietary supplements, especially when it is not possible to achieve optimal levels through diet.
These supplements come in two forms – organic and inorganic. Studies have shown that the organic form of selenium is more easily absorbed and utilized by the body than the inorganic form. If you need additional selenium intake, the organic version is preferable – this will ensure better bioavailability and higher effectiveness of the mineral.
Selenium Deficiency: Symptoms
When a person does not consume enough selenium, the following signs and symptoms may be present:
- Muscle weakness
- Chronic fatigue
- Hair loss
- Impaired immunity
- Impaired digestion
The recommended intake depends on a person’s age and gender, but in general the daily dose for adults is 55 mcg daily and for children 20 mcg daily.
Health benefits of selenium intake
Selenium and immunity
A strong and healthy immune system is an integral part of the body’s fight against infections caused by bacteria or viruses. Closely related to selenium are over 30 selenoproteins, which act as powerful antioxidants and are key to immune function
Antioxidants play an important role in preventing cell damage that can occur due to excess free radicals in the body. When oxidative stress is lowered, the risks of developing diseases and infections decrease because the number of damaged cells is reduced.
In addition to this important antioxidant effect, selenium is also associated with anti-inflammatory, antiviral and antibacterial properties. These properties play an essential role in regulating inflammatory processes and the body’s immune response.
In conclusion, selenium is essential for maintaining a healthy immune system and protection against various types of infections. This mineral has a dual role as an antioxidant and a regulator of inflammatory processes, which gives it extreme importance for the body’s overall health and resilience.
Selenium and viral infections
Selenium deficiency is directly linked to an increased risk of viral infections. Decreased levels of selenium in the body can cause increased oxidative stress, which in turn can lead to increased levels of inflammation in the body. The most convincing evidence relating to the harmful effects of selenium deficiency comes from certain regions in China where the soil is poor in selenium. These areas have seen an increase in diseases, including a specific type of cardiomyopathy caused by a virus. It has been found that this disease can be prevented with selenium intake.
A 2013 study in the Journal of Nutrition studied the relationship between selenium and two viruses, coxsackie virus and influenza. In this experiment, which lasted four weeks, mice were divided into two groups: one was fed a selenium-deficient diet and the other was fed foods rich in selenium. After this period, both groups were infected with coxsackie virus and influenza virus. The results of the experiment showed that the selenium-deficient group had a fivefold greater risk of developing the serious heart disease myocarditis. In addition, the selenium-deficient mice that were infected with influenza virus also had severe lung inflammation. These results highlight the important role of selenium in the immune system and protective functions against viral infections.
Selenium and thyroid health
Due to selenium’s antioxidant properties, research has shown that it plays a key role in thyroid function and thyroid hormone production. In fact, in the elderly, the thyroid is the organ with the highest amount of selenium per gram of tissue. Low selenium levels have been found to contribute to autoimmune thyroid diseases including Hashimoto’s thyroiditis, hypothyroidism, thyroid cancer, and also an enlarged thyroid gland.
A popular study in 2002 looked at a group of patients with autoimmune thyroid disease. Some received a placebo, while others received 200 mcg of selenium for three months. The group that took selenium had reduced antibodies to thyroid peroxidase from 100 percent to 63.6 percent, and ultrasounds showed less thyroid inflammation. This study provides compelling evidence that selenium has a significant impact on thyroid health.
Selenium and cardiovascular disease
Cardiovascular disease is one of the leading causes of death among people worldwide. Selenium plays an important role in maintaining cardiovascular health. Here’s how selenium is related to cardiovascular disease:
- Antioxidant protection: selenium is a component of antioxidant enzymes in the body, such as glutathione peroxidase, which protect cells from oxidative stress. Oxidative stress can contribute to the development of atherosclerosis, inflammation and other cardiovascular problems.
- Inflammation: selenium has anti-inflammatory properties that are important for heart health. Chronic inflammation in the blood vessels can contribute to the development of heart disease, and selenium can help in reducing inflammatory processes in the body.
- Preventing oxidative damage: Selenium can prevent oxidative damage to lipids (fats) in blood vessels, and this can reduce the risk of atherosclerotic plaque formation.
- Heart function: Selenium plays an important role in maintaining normal heart and muscle function. Selenium deficiency can lead to problems with heart function.
Selenium is an essential mineral with powerful antioxidant, anti-inflammatory and immunostimulant properties. This trace element helps reduce thyroid hormone levels in autoimmune thyroid diseases. It is useful in cardiovascular diseases and has a general strengthening effect on the whole organism.