The selenium content in the soil is very specific, which sometimes results in large regional differences. In Germany, people tend to have a smaller amount of selenium, around 6.6 mg, which is why it is not uncommon for selenium deficiency symptoms to occur in this country. Things are different in the USA, where every citizen can enjoy up to 20 mg of selenium in their body.
Many organs could not function without selenium
The selenium concentration is by no means evenly distributed in the body. The highest concentrations of selenium are in our kidneys and the lowest in the brain. In order to understand this better, we would like to briefly discuss the element selenium.
The chemical element selenium
The non-metal with the chemical symbol Se was discovered in 1817 by the Swedish chemist Jens Jakob Berzelius, who based the name on the Greek moon goddess Selene. The properties of chalcogen, which can be translated as an ore former, are similar to those of tellurium or sulfur. In 1957, it was discovered that selenium is an essential trace element, and in the 1970s, selenium deficiency symptoms were first recognized as such by medicine.As a component of the amino acid selenocysteine, selenium is incorporated into proteins. The fact that selenium is very important for our health is also shown by the fact that, as of November 2020, there are more than 36,000 publications on the mechanisms of action of selenium.
Why is selenium so important for us?
Selenium primarily has antioxidant functions. In addition to superoxide dismutase and catalase, the selenium protein glutathione peroxidase is one of the three essential components of the antioxidant defense. In addition, selenium is essential for our thyroid, immune system and brain. Cardiomyopathy is one of the particularly dangerous symptoms of selenium deficiency. In men, selenium deficiency can limit sperm production to such an extent that it can lead to infertility.
Selenium deficiency symptoms related to the immune system
There is usually a balance between the TH1 and TH2 immune responses. If there is a selenium deficiency, this gets mixed up, which can lead to allergies and autoimmune diseases. This is accompanied by a loss of resistance of the immune system against viruses, bacteria, fungi and tumor cells. One could also say that a selenium deficiency has the effect of pathogenic germs becoming more aggressive.
As a first measure against such selenium deficiency symptoms, high doses of sodium selenite are recommended because this immediately strengthens the TH1 immune response.
Selenium and vaccinations
In order for a vaccination to have the hoped-for success, there must be an intact immune response. Several studies have shown that the effectiveness of flu vaccinations in older people can be lower if there is a weakening immune response. It is very likely that this finding can be directly transferred to vaccinations against COVID-19.
Another double-blind study examined the effect of low selenium status in polio vaccinations. 66 adult participants were divided into three groups. In group 1, the test subjects received 100 μg of sodium selenite per day, in group 2 only 50 μg and group 3 received placebos.
The result was clear. The sodium selenite boosted the immune system so that poliovirus clearance was significantly improved after vaccination. The stronger immune response of the Th1 lymphocytes even applied to a later polio vaccination with a live vaccine.
Selenium is also important for the thyroid
This organ needs and contains particularly high levels of iodine and selenium. Therefore, a relative selenium deficiency is very noticeable here. Selenium proteins are for education
the active thyroid hormone T3 is essential. Selenium also supports the recycling of the resulting hydrogen peroxide.
The hormones produced by the thyroid control many processes in the body, such as:
- Energy and bone metabolism
- digestion
- Cardiovascular system
- mental or psychological condition
Therefore, many very different selenium deficiency symptoms are triggered by inadequate thyroid function, whose tissue is even destroyed if there is a permanent selenium deficiency.
Infertility in men due to selenium deficiency
Our body has remarkable dynamics in every respect. This is expressed, among other things, in the fact that he goes to great lengths to ensure selenium supply where it is absolutely necessary. The brain and testicles are given a particularly high priority in this regard.
Sperm production is unthinkable without selenium when it comes to sperm that are supposed to function. Their quality depends on the selenium supply. If the latter is not sufficiently guaranteed, infertility can occur in men. Anyone faced with such a scenario should definitely consider taking an appropriate dietary supplement as a simple first step. If the infertility has another cause, additional selenium definitely won't do any harm.
Selenium as a brain booster
Our brain only contains around 2.3 percent of the selenium in our body. If some of this small amount is deprived of it, the brain withdraws this important substance from other organs that also urgently need selenium. As a result, the activity of glutathione peroxidase, a selenium protein that makes an important contribution to the reduction of oxidative stress in the liver, immediately decreases by 90 percent. This ensures that the activity of glutathione peroxidase in the cells in the brain, which are very sensitive to oxidative stress, is reduced by a maximum of around ten percent.
In fact, cognitive tests on older people always gave poor results when they had low selenium status. A similar effect can be seen on the other side of the age scale. The fetus needs active thyroid hormone from its mother for brain development because it cannot yet produce these substances itself. Certain selenium proteins are needed to activate thyroid hormones. It is therefore very important that pregnant women are provided with sufficient selenium to ensure that the cognitive development of their babies can follow a normal course.
Which foods contain a relatively high amount of selenium?
It is primarily the composition of the soil that determines whether the plants and animals that live there absorb sufficient amounts of selenium. In addition, it can be roughly stated that protein-rich foods provide more selenium than, for example, a purely vegan diet, since the element selenium is essentially found in protein fractions. For this reason, foods such as meat, offal, fish and nuts contain relatively high amounts of selenium. At this point it is important to refer to the Brazil nut ; each individual nut of this variety already contains 70 to 90 µg of selenium. Yes: Brazil nuts contain selenomethionine, a compound that is stored in the tissue in exchange for our amino acid methionine. In other words: The selenium contained in Brazil nuts is difficult to make available for the metabolism. It is therefore cheaper to take a selenium compound that is 100% available to the metabolism: sodium selenite is therefore the selenium of choice.
But the edge areas of cereal grains are also valuable sources of selenium. However, when they are processed into white flour, most of the selenium is lost.
Summary of the findings on physiological cell protection through selenium
- Cell protection: As a component of glutathione peroxidase, selenium plays an important role as an antioxidant. Selenium protects cell membranes, erythrocytes and DNA from oxidative damage.
- Thyroid: Selenium is an important cofactor for the formation of active thyroid hormones, which control basal metabolism, cell activities, their differentiation and growth.
- Immune System: Selenium supports humoral and cellular immunity by contributing to antibody production, lymphocyte proliferation, interferon synthesis, cytokine production, and regulation of cytotoxic NK and T cells.
- Tumor prevention: Strengthening the immune system has an anti-carcinogenic effect, as selenium has a growth-inhibiting and at the same time cell death-promoting effect on emerging tumor cells.
- Detoxification: Selenium helps to bind heavy metals, which can then be more easily removed from the body. Selenium also protects liver cells particularly effectively.
- Hair and nails: Selenium is a driving force for the protection, maintenance and growth of hair and nails.
Selenium can protect against severe COVID-19 courses
Selenium deficiency must be avoided at all costs, especially in the case of an infection with Sars-CoV-2, which can lead to acute respiratory failure, Acute Respiratory Distress Syndrome (ARDS). It has now been scientifically proven that a selenium deficiency is associated with an increased risk of mortality, especially in the case of COVID-19.
