The essential nutrients for human body mainly include vitamins, water, protein, carbohydrates, fats and minerals.

In minerals, besides major elements such as potassium, calcium, sodium and magnesium, trace elements such as iron, zinc, copper and selenium are also indispensable. Although they account for less than one tenth of the total weight of human body, they are essential elements to maintain health.

In recent years, with a series of selenium-enriched agricultural products and selenium-enriched health products such as selenium-enriched rice, selenium-enriched eggs, selenium-enriched tea, selenium-enriched fruits and selenium-enriched health products selling well, the relationship between selenium and human nutrition and health has gradually attracted people's attention.

Is selenium the most expensive thing?

Selenium, 18 17, was discovered by Swedish chemist Joens Jacobs. It is named Selene (Greek means moon), and its chemical symbol is selenium. It is a nonmetal of VIA group in the fourth period of the periodic table of chemical elements.

Selenium exists in nature as inorganic selenium and organic selenium. Inorganic selenium generally refers to sodium selenite and sodium selenate, while organic selenium is a combination of selenium and amino acids through biotransformation, and generally exists in the form of selenocysteine and selenomethionine.

Selenium has many values and can be used as a catalyst for glass coloring, photosensitive materials and electrolytic manganese industry in industry. However, more important is the value of selenium in biomedicine.

It is an essential nutrient for all kinds of living things, including bacteria, plants and animals. In the medical and nutritional circles at home and abroad, selenium is known as "the kindling of life", "the element of longevity", "the king of cancer", "the natural antidote" and "the protector of health". Studies have shown that selenium may have great potential in anti-oxidation, anti-aging, anti-cancer, enhancing immune function, preventing cardiovascular diseases and antivirus [1].

Anti-oxidation and anti-aging

The existence of life depends on oxygen, and various oxidation processes can help life obtain the energy needed for life activities. On the other hand, oxygen may also cause oxidative damage to life.

In the process of metabolism, human cells will constantly produce free radicals, which can combine with oxygen-containing substances with strong activity to form "active oxygen free radicals" and become killers of health and longevity. At present, the world medical community has recognized that free radicals are one of the chief culprits of human aging, and are closely related to cardiovascular diseases, cancer, diabetes and other diseases 100. Faced with such a serious threat of free radicals, the human body has formed a whole set of anti-oxidation defense system, and selenium is an important member of this system.

DuntasLH of the University of Athens in Greece and others summarized many epidemiological studies related to selenium in recent years. They found that many previously damaged physiological functions would be significantly improved by supplementing a certain amount of selenium to selenium-deficient people [2].

The reason may be that after selenium is ingested by human body, it can participate in the synthesis of antioxidant selenoproteins in important organs and eliminate excessive free radicals in the body, thus having a potential role in resisting the damage of free radicals to tissues and organs.

cancer anticancer

Selenium is an effective killer of cancer cells, which can block the important energy source of cancer cells, improve the level of cyclic adenosine monophosphate in cancer cells, and form an internal environment to inhibit the division and proliferation of cancer cells in the body.

In an epidemiological study in 2008, Polish scientists found that the incidence of cancer was negatively correlated with the selenium content in blood, and the incidence of cancer in countries and regions with low selenium content in soil and food was significantly higher than that in countries and regions with high selenium content [3]. The incidence and mortality of prostate cancer, intestinal cancer, liver cancer, lung cancer, breast cancer and other malignant tumors in selenium-deficient and selenium-deficient areas are significantly higher than those in selenium-enriched areas, and the blood selenium content of cancer death patients is obviously low.

Preventing cardiovascular diseases?

Selenium is an important element to maintain the normal function of the heart, which can protect and repair the heart.

Researchers such as BenstoemC in Germany have conducted in-depth research on the relationship between selenium and the normal function of cardiovascular and cerebrovascular systems and related diseases in recent ten years. They believe that the decrease of selenium content in human blood will lead to the decrease of free radical scavenging function in the body, which will lead to the increase of harmful substance deposition, the thickening of blood vessel wall, the decrease of blood vessel elasticity, the increase of blood pressure, the slow blood flow and the decrease of oxygen transport function, thus inducing various cardiovascular and cerebrovascular diseases [4]. Therefore, scientific selenium supplementation may have a good effect on preventing cardiovascular and cerebrovascular diseases such as hypertension and arteriosclerosis.

In addition to the above potential, HoffmannPR of the University of Hawaii also found that selenium can stimulate the production of immunoglobulins and antibodies, improve the immune function of the body, and enhance the disease resistance of the body [5].

Selenium may also be a "good hand" for detoxification, detoxification and resistance to heavy metals. Selenium has a strong affinity for heavy metals, can combine with harmful metal ions to form a metal selenoprotein complex, and can be directly excreted to reduce the toxicity of heavy metal ions, thus having the potential of detoxification, detoxification and anti-pollution.

In addition, selenium may have many other physiological functions, such as improving the oxygen carrying capacity of red blood cells, lowering blood sugar of diabetic patients, and regulating insulin metabolism.

Although the research on the physiological function of selenium and its application in biomedicine has attracted much attention, scientists have made some important achievements. However, up to now, the main molecular mechanism of selenium maintaining human health and its complex relationship with the occurrence and development of diseases are not completely clear, and a lot of basic and clinical scientific research is still needed in the future. We look forward to further exploring and verifying the "wild power" of selenium through more and more selenium-related biological experiments and clinical practices, so as to serve the healthy life of human beings.

Now, back to the topic. Is it meaningful to supplement selenium?

Two sentences:

1. If you lack selenium, you really need to supplement selenium, but don't blindly supplement selenium! !

2. Normal people have been able to get enough selenium from their diet, but the demand for selenium in human body is actually only one step away from the amount of selenium poisoning.

Specifically,

Although selenium plays an important role in maintaining human health, there is no organ for long-term storage of selenium in human body, and selenium needed for metabolism needs to be continuously supplemented from diet. ?

There are many natural foods with high selenium content in daily life, such as meat, eggs, fish, seafood, heart, liver, kidney and other organs of animals, among which eggs contain more selenium than meat? [6]。 Vegetables such as shepherd's purse, asparagus, peas, Chinese cabbage, pumpkin, onion and tomato also contain a certain amount of selenium. Eating more of these foods can safely and effectively supplement selenium.

However, it is worth noting that although selenium is important, it is not necessary to supplement it as much as possible? [7]。

According to the Reference Intake of Dietary Nutrients for China Residents (version 20 16), the recommended daily intake of selenium for adults is 60 micrograms, and the maximum tolerable intake is 400 micrograms.

Normal people can get enough selenium as long as they are not partial to food and picky eaters, pay attention to balanced nutrition and do not need special supplements. However, adding 50 micrograms of selenium to the daily food of selenium-deficient adults has a health care effect.

Selenium supplementation needs to be accurate to microgram, and the demand for selenium in human body is actually only one step away from the amount of selenium poisoning. A little carelessness may lead to bad consequences.

Some people think that they lack selenium, so they take selenium-enriched food as nutrition for a long time, which makes the human body in a state of high selenium, and selenium poisoning may occur in a state of high selenium for a long time. Once selenium poisoning occurs, human body will have a series of symptoms, such as dull skin pain, numbness of limbs, dizziness, loss of appetite, hair loss, thick nails, rash, itchy skin, pale face, gastrointestinal dysfunction, indigestion, etc., and even life-threatening.

Therefore, although selenium should be supplemented, it cannot be supplemented more!

If you are not sure whether you need selenium supplementation, it is recommended to go to the hospital for detailed testing to confirm.