Harm of selenium deficiency
Like any other essential nutrient, selenium is necessary for human body to maintain normal function. Adults need to consume 55 micrograms of selenium every day, and the normal range of selenium content in blood is 70- 160 ng/ml (equivalent to micrograms/liter).
Glutathione peroxidase is an important peroxidase widely existing in the body. Its active center is selenocysteine, and its activity is affected by the selenium level in the body. Selenium can combine with sulfur-containing amino acid (cysteine) residues in protein to form selenoprotein, which transports selenium to various parts of the body, thus promoting the normal functions of various organs.
Plants can directly absorb selenium from soil, while humans mainly get selenium through food. When the selenium content in the living environment is too low, and when the selenium content in local crops is too low, people who live in selenium-deficient areas and have low selenium content in food are often prone to selenium deficiency.
There are two famous diseases that selenium deficiency does harm to the body, one is Keshan disease and the other is Kaschin-Beck disease.
Keshan disease, also known as endemic cardiomyopathy, is a special disease discovered by 1935 in Keshan area of Heilongjiang province. The selenium content in the environment and food in this area is low. Selenium deficiency is one of the important causes of this disease, but it is not the only cause. People in this area are generally deficient in selenium, but only a few people suffer from Keshan disease. Nutrition, flora and virus infection may also play an important role.
Kashin-Beck disease, also known as dwarf disease and abacus bead disease in China, is an endemic deformity osteoarthropathy, which occurs in eastern Siberia, northern Korea and mountainous areas in northeast and northwest China. This disease is related to the lack of selenium and iodine in living environment and diet.
The environmental selenium content in many parts of the world is very low, such as the northeast and northwest of China, eastern Europe, central Europe and parts of Africa. However, with the improvement of dietary awareness and the global circulation of food, this typical selenium-deficient endemic disease has been very rare.
At present, the lack of selenium in people's bodies is often due to excessive mineral loss or impaired selenium absorption capacity. For example, patients with inflammatory bowel disease (mainly including ulcerative colitis and Crohn's disease) are more prone to selenium deficiency due to frequent diarrhea; Patients with kidney disease, Alzheimer's disease, thyroid disease or HIV may be deficient in selenium; In addition, people who often take drugs, such as steroids, birth control pills, olanzapine and other psychotropic drugs, may lead to selenium deficiency.
Health benefits of 1 1 selenium
When the selenium content in human body is sufficient, it can obviously promote health. At present, it is found that selenium has at least the following 1 1 benefits to human body.
1. Antioxidant and anti-inflammatory effects
Selenium is a powerful antioxidant. Selenium protein and glutathione peroxidase play an important role in human redox system, which can help human body neutralize oxygen free radicals and decompose peroxides, thus reducing the damage of oxidative stress to cells.
Selenium can also inhibit the activity of NF-κB, an important pro-inflammatory mediator, and reduce the contents of pro-inflammatory cytokines (such as IL-6 and TNF-α) and pro-inflammatory mediators (such as C-reactive protein) in blood, thus reducing the level of inflammation in vivo.
2. Enhance immunity
Selenium is very important for maintaining the normal function of the immune system. Adequate selenium can not only reduce the damage of oxidative stress to immune cells, but also enhance the activity of immune cells and promote antibody synthesis. When selenium is deficient, the immune response will become dull, and the activation and differentiation of immune cells will be affected.
HIV infection can cause selenium deficiency, and selenium supplementation can help people better cope with the virus. Animal experiments and cell experiments show that selenium can inhibit virus replication. The risk of death of AIDS patients with selenium deficiency is 20 times higher than that of patients with selenium deficiency. Routine treatment and selenium supplementation can improve the quality of life of virus carriers.
3. Promote thyroid health
The most selenium-rich organ in human body is thyroid, and the selenium content in thyroid is higher than any other organ. Selenium can protect thyroid from oxidative stress and promote thyroid to maintain normal functions, such as regulating metabolism, growth and development; At the same time, selenium can also promote the number of regulatory T cells, reduce the production of anti-thyroid related antibodies, and reduce the attack of immune system on thyroid.
The selenium content of patients with thyroid diseases such as Hashimoto's disease, Graves' disease and hypothyroidism is often low. For patients with selenium-deficient thyroid diseases, selenium supplementation can often improve symptoms, mood and quality of life.
4. Prevention of cardiovascular and cerebrovascular diseases
Adequate selenium helps to maintain heart health and reduce the risk of heart disease, not only Keshan disease, but also other types of heart disease. By reducing the level of oxidative stress and inflammation, adequate selenium can also inhibit atherosclerosis, thus reducing the risk of cardiovascular and cerebrovascular diseases.
The study found that people with sufficient selenium content in their bodies have significantly lower risk of heart disease than those with insufficient selenium content. Selenium supplementation in patients with heart disease can also reduce the level of inflammation in the body.
5. Reduce cancer risk
Adequate selenium can protect cells from oxidative stress, promote DNA repair and reduce the risk of cancer. Selenium can promote the immune system to eliminate tumor cells, inhibit the growth of tumor cells and delay the progress of cancer.
Studies have found that adequate selenium can reduce the risk of breast cancer, lung cancer, prostate cancer and colon cancer, and improve the quality of life of patients with cervical cancer and uterine cancer.
6. Prevention of cognitive impairment
Oxidative stress is one of the main reasons for the occurrence and development of neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease and multiple sclerosis.
The study found that:
7. Increase the fertility rate
Infertility is a very common problem in modern society, which plagues more than 15% couples. Adequate selenium is helpful to improve the fertility of both couples.
For men, adequate selenium can improve sperm motility and quality; Women's demand for selenium increases during pregnancy and lactation, and adequate selenium is helpful to reduce the risk of miscarriage and preeclampsia.
8. Regulate emotions
Selenium deficiency may lead to emotional and psychological problems, such as depression, anxiety, fatigue and insanity.
The study found that:
9. Improve asthma
Adequate selenium is helpful to reduce the level of oxidative stress and inflammation in the lungs, improve lung function and improve asthma-related symptoms. Some studies have found that after selenium supplementation, the symptoms of asthma patients are alleviated and the frequency of medication is significantly reduced.
10. Adjust the biological clock
The physiological activities of human body have obvious rhythm, which is called biological clock. When the rhythm of life changes and the biological clock is disordered, abnormal symptoms and even diseases may appear in the human body. For example, people who often suffer from insomnia have a disordered circadian rhythm.
Selenium is a powerful timing factor, which can help the body adjust the disordered biological clock. Cell experiments show that selenocysteine can regulate the genes related to biological clock, promote their expression at appropriate time, and thus correct the biological clock. This substance is found in garlic, onions and cauliflower.
1 1. Reduce the harm of mercury poisoning.
Mercury is a heavy metal that is harmful to people. It can enter the human body through contact and inhalation, and has strong neurotoxicity, which can be life-threatening in severe cases.
Selenium can combine with mercury to promote the discharge of mercury, thus reducing the harm of mercury to human body; At the same time, due to the combination of mercury and selenium, the available selenium in the body may be reduced, and some symptoms of selenium deficiency may occur, but these are much less harmful than mercury poisoning.
With the popularization of selenium-enriched foods, most people know the benefits of selenium and the harm of selenium deficiency, so will selenium supplementation be toxic and harmful to human body?
Excessive selenium can lead to poisoning.
Of course there is! Selenium is an essential trace element for human body, which is beneficial to human body only within a certain range. Adults who consume more than 400 micrograms of selenium every day may be poisoned by selenium, whether through a large number of selenium-enriched foods or selenium supplementation.
When the selenium level in the body is too high, there will be hair loss, bad breath (metallic or garlic smell), diarrhea, vomiting, dermatitis, tachycardia, hypotension, tremor and other symptoms, and even damage organs such as liver, kidney, heart, thyroid, nerves and brain in severe cases, increasing the risk of diabetes, cancer and thyroid diseases.
At the same time, selenium may also interact with many drugs, such as acid inhibitors, chemotherapy drugs, cortisol-like hormones, nicotinic acid (vitamin B3), cholesterol-lowering statins, contraceptives and so on. , will affect the efficacy.
Food warm heart summary:
Selenium is an essential trace mineral for human health, which can promote the health of immune system, thyroid, heart, brain and other organs. Adequate selenium has many benefits to human body, while lack of selenium may lead to many diseases and symptoms; It should be noted that the more selenium is not the better, but it will lead to selenium poisoning, damage health and increase the risk of various diseases.
Reference materials:
1./blog/ Health-Benefits-Selenium/
2./ Nutrition/Selenium-Benefits
3./ Nutrition/Selenium-Benefits/