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Abstract: Throughout the ages, exploring the mysteries of life, protecting human health and prolonging life have become the beautiful wishes that human beings dream of. At present, it has been found that the content of many elements in human body is less than one thousandth of human body weight, and the total amount is less than one thousandth of human body weight, so it is named trace elements. Trace elements are the core components of enzymes, hormones, vitamins and other active substances in human body, which play an important role in normal metabolism and health of human body. Modern medicine has proved that the amount of trace elements contained in human body is closely related to cancer, cardiovascular diseases and human life span. This paper aims to explore the relationship between trace elements and human health.
Keywords: trace elements, human body content, human health
At present, it is determined that there are 14 kinds of trace elements that are beneficial to human body and must be ingested, including: iron, copper, zinc, manganese, chromium, cobalt, vanadium, tin, nickel, molybdenum, iodine, fluorine, tin and silicon. When various physiological activities are carried out in the body or people participate in external sports, they all play different roles and are very important for maintaining human health.
I. Types and contents of trace elements in human body
The so-called trace elements refer to a large number of elements. There are 1 1 macro elements in human body, which are arranged according to the required amount: oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus, potassium, sulfur, sodium, chlorine and magnesium. Among them, oxygen, carbon, hydrogen and nitrogen account for 95% of human body mass, the rest is about 4%, and trace elements account for about 1%. Among the essential elements for life, there are 14 kinds of metal elements * *, in which the contents of potassium, sodium, calcium and magnesium account for more than 99% of the total metal elements in human body, and the contents of the other 10 kinds of elements are very small. Traditionally, elements with content higher than 0.0 1% are called macro elements, and elements with content lower than this value are called trace elements. If the human body lacks some constant elements, it will cause human dysfunction, but this rarely happens. The general diet contains enough macro elements. Although the content of trace elements in the body is very small, their role in the process of life cannot be underestimated. Without these essential trace elements, the activity of enzymes will be reduced or completely lost, and the synthesis and metabolism of hormones, protein and vitamins will be hindered, making it difficult for people to continue their lives.
Chart 1 human trace element content and daily demand
microelement
Iron, manganese, fluorine, chromium, zinc, copper, cobalt, molybdenum, iodine, selenium and vanadium.
Human body content mg/g
60 0.2 37 0.2 33 1.0 0.02 0. 1 0.2 0.2 0.3
Daily requirement of mg
13 3 3 0.5 13 5 0.3 0.2 0. 1 0.00 1 13
As can be seen from the above table, trace elements are very low in human body, but they are indispensable. These trace elements must have a certain amount in daily diet.
There are also two possible essential trace elements, nickel and arsenic, and their contents in the body are 0. 1ug/g respectively.
The main functions of trace elements in human body are: 1. Carry macro elements and bring a large number of elements to various organizations. 2. Act as the active center of various enzymes in organisms and promote metabolism. Enzymes are essential catalysts for many chemical reactions in organisms, but many trace elements are components or activators of enzymes. For example, zinc is related to the activity or structure of more than 200 enzymes.
Participate in the role of various hormones in the body. For example, zinc can promote the function of sex hormones, and chromium can promote the function of islets.
Second, the specific introduction of trace elements
At present, the function of some trace elements is not completely clear, so the following is just a brief introduction.
1. iodine
Iodine mainly exists in the form of inorganic iodide in food, and other forms of inorganic iodine are absorbed first and then reduced to iodide. Iodine in digestive organs is quickly and almost completely absorbed. The content of iodine in human body is about 25mg, half of which is distributed in thyroid gland. The function of thyroid gland is to synthesize and secrete a thyroid hormone, which is an important hormone for promoting human growth and metabolism, especially for the development of brain cells. Therefore, iodine is called "intellectual element".
2. Iron
Iron belongs to Group VIII transition metal in D region of the periodic table of elements, and the most common oxidation states are Fe (Ⅲ) and Fe (Ⅱ). The electronic configuration of Fe (Ⅲ) is 3d5, which is paramagnetic. The electronic configuration of Fe (Ⅱ) is 3d6, and its high spin state is paramagnetic and its low spin state is diamagnetic. Fe (Ⅲ) and Fe (Ⅱ) are both strong Lewis acids, which are easy to form octahedral complexes. Generally, the iron in an adult's body is about 3~5g, which is equivalent to the weight of a small nail and mainly exists in the blood. These iron mainly exist in the form of complex ions, which can form hemoglobin and myoglobin with heme and protein, and play the role of transporting and storing oxygen. When the human body is short of iron, it will affect the formation of hemoglobin and myoglobin, thus reducing the number of red blood cells or hemoglobin content in the blood, affecting the oxygen carrying capacity and causing physiological disorders of the whole body. This is anemia. According to the survey of the World Health Organization, iron deficiency anemia is a common disease in the world, and the root of infant anemia lies in iron deficiency. Many children are bean sprouts, and iron deficiency is also an important reason. The most convenient way to prevent iron deficiency in human body is to adjust diet, eat more iron-rich viscera such as animal liver, followed by lean meat and egg yolk. Some vegetables and fruits also contain more iron. In addition, the use of iron pot cooking can also supplement human iron. Under acidic conditions, human intestines and stomach are conducive to the absorption of iron, so acidic vitamin C in food is conducive to the absorption and utilization of iron.
3. Zinc
Zinc is located in group Ⅱ b of the periodic table of elements. Zinc in the compound exists in +2 valence oxidation state and has a full 3d electronic shell, so it has strong stability. Zinc can be used in many biological processes. This is a strong Lewis acid. Zinc is about 200 components of human body, and it is also a lot of catalysts. After zinc deficiency, various zinc-containing activities decreased, the synthesis of DNA, RNA and protein decreased, and amino acid metabolism was disordered. Because zinc is closely related to the synthesis of many nucleic acids and protein, it can promote the absorption and synthesis of protein and promote cell division, growth and regeneration through the polymerization of DNA and RNA. Therefore, zinc is of great nutritional significance to the growth and development of infants and adolescents.
4. Copper
Copper is one of the essential trace elements for human body. The content of copper in adult normal people is about 60~ 120mg, which is distributed in all parts of the body and has a high concentration in liver, brain, heart and kidney. In blood, copper mainly exists in red blood cells and serum. Similar to iron, copper also participates in the process of human hematopoiesis, catalyzes the synthesis of hemoglobin, and is also a component of some metalloenzymes in human body.
5. Fluoride
Fluorine is a halogen element with valence electron configuration of 2s22p5 and the highest electronegativity (4. 10). It is the most active nonmetal. It exists in the form of F- ion in aqueous solution. Element fluorine (F2) is a yellow-green gas with strong irritation. Its typical chemical properties are strong oxidation: it can react with many substances at room temperature and almost all substances at high temperature. Modern medicine has confirmed that fluorine is an essential trace element for human body and plays an important role in teeth and bones. The fluorine content in normal bones is about 0.0 1%~0.02%, and that in teeth is about 0.0 1%~0.03%. Trace fluorine in human body is beneficial to the utilization of calcium and phosphorus and its deposition in bones, which can accelerate the formation of bones, increase the hardness of bones and stimulate the proliferation of osteoblasts. Trace fluorine can be adsorbed by hydroxyapatite in enamel to form a hard and dense protective layer, thus inhibiting the activity of acidophilic bacteria and protecting teeth. When the fluorine content in drinking water decreases, dental caries will occur, which will not only harm teeth, but also lead to other oral and brain diseases. The World Health Organization has listed dental caries as the third largest disease after cardiovascular diseases and cancer. In order to prevent dental caries, oxygen-increasing measures can be taken, such as adding fluoride to drinking water, using fluoride toothpaste, and eating fluoride-containing foods and drinks, such as shellfish, jellyfish, wine and tea drinks.
6.molybdenum
Molybdenum is the second transition element of group ⅵ b in D region of periodic system. The valence electron configuration of Mo is 4d55s 1, and there are many oxidation states from -2 to +6. The low oxidation state is unstable, and the common oxidation states are +4, +5 and +6. The formation of polybasic acid complexes is a characteristic of highly oxidized molybdenum. Trace element molybdenum is widely distributed in human body. The total amount of molybdenum in adults is about 9mg, and the highest content is in the liver, followed by the kidney.
7. Vanadium
Normal adults, * * * contains about 25mg of vanadium, and the content of vanadium in blood is very small. Most of the vanadium in human body is concentrated in bones and teeth. Vanadium can stimulate human hematopoietic function, increase hemoglobin and red blood cells, and improve human hematopoietic function. Vanadium can also inhibit the synthesis of cholesterol and reduce the degree of arteriosclerosis.
8. Selenium
In the periodic table of elements, Se is a group VI A element, just like oxygen and sulfur. The valence electron configuration of Se is 4s24p4, and there are many oxidation states (-2, 0, +4, +6). The high oxidation state often exists in the form of oxyacid radical, and the low oxidation state of -2 valence is H2Se or-SeH. These forms of existence are very similar to the corresponding oxidation state of S, and selenium is one of the essential trace elements for human body, which is closely related to human health. In human body, selenium has the highest content in the heart and has a protective effect on myocardium.
9. Chromium
Chromium is an essential element to participate in the sugar or fat metabolism of insulin and to maintain normal cholesterol. Chromium can help insulin to play its role, prevent arteriosclerosis, promote protein metabolism and synthesis, and promote growth and development. But when the chromium content increases, such as long-term inhalation of chromate powder, lung cancer can be induced.
10. cobalt
In the periodic table of elements, cobalt and iron are adjacent and belong to the transition metals of Group VIII in D region. Price electron configuration 3d74s2. There are many kinds of oxidation states, and the common important oxidation states are Co (Ⅱ) and Co (Ⅲ). Under normal circumstances, Co2+ ions are stable and Co3+ ions are highly oxidized. They all have strong coordination ability and can form complexes with various ligands, and their three-dimensional geometric configuration is mainly octahedron. Cobalt is an essential component of vitamin B 12, and B 12 is an essential component of red blood cell formation. Cobalt plays an important role in protein, fat, carbohydrate metabolism and hemoglobin synthesis, and can dilate blood vessels and lower blood pressure.
1 1. manganese
Manganese participates in many enzyme-catalyzed reactions and is inseparable from all living things.
Third, the human body lacks trace elements.
With the development of social industrialization and the change of people's lifestyle, it also affects the balance of trace elements in human body, leading to many diseases.
Iodine deficiency will do great harm to human body, especially to children, infants and pregnant women. If iodine deficiency is serious in infants, bone growth and brain development will be seriously affected, and dementia will occur, which is characterized by short stature, slow movement, loss of appetite and mental retardation. In addition, medical research in recent years shows that human iodine deficiency can also induce breast cancer, ovarian cancer, uterine cancer and thyroid cancer. The most convenient and economical way to prevent iodine deficiency is to add iodine to salt, and at the same time, you can often eat seafood rich in iodine such as shrimp, hairtail, kelp and laver.
Zinc deficiency can cause zinc deficiency dwarfs, and zinc supplementation can eliminate zinc deficiency dwarfs. Zinc promotes appetite and digestive function through the medium of amino acid B, and also affects taste and appetite through the protein taste body containing zinc in saliva. After zinc deficiency, the taste and appetite of people and animals decrease, and zinc supplementation can improve them. At present, the early manifestations of zinc deficiency in infants have been classified as anorexia, migraine hardness, eating and pica. Some people think that abnormal taste and smell in early pregnancy are also related to zinc deficiency. Zinc deficiency impairs immune function and reproductive function.
Without copper, the oxidative metabolism in nerve, muscle and liver can not be regulated, and the human body will have symptoms such as dyskinesia and nervous disorder. If there is a serious shortage of copper in infancy, it will lead to stunting, hepatosplenomegaly, anorexia and other diseases. If adults are seriously short of copper, there will be diseases such as blood vessel rupture, internal bleeding and bone brittle. When people are short of copper, they can eat more copper-rich foods such as meat, eggs, beans, coarse grains and vegetables or take copper preparations.
Molybdenum deficiency can lead to neurological abnormalities, mental retardation and affect bone growth. More seriously, the reduction of molybdenum content in human body can increase the incidence of esophageal cancer. As we all know, nitrosamine carcinogens are an important factor in inducing esophageal cancer. The precursors of nitrosamines are nitrite and amine, and nitrosamines are synthesized under appropriate acid-base conditions. Nitrite mainly comes from NO3- in the environment. Reducing the source of NO3- is an effective measure to prevent the high incidence of esophageal cancer. Molybdenum is a useful anticancer element, which can effectively reduce the precursors NO3-and NO2-of nitrosamines and inhibit the formation of nitrosamine carcinogens. Molybdenum intake is related to diet. Animals' liver and kidney, grains and beans are rich in molybdenum, which is really a good product for molybdenum supplementation.
Vanadium deficiency leads to abnormal bone development, slow growth and impaired reproductive function. In addition, both enamel and dentin belong to hydroxyapatite, and vanadium can replace hydroxyapatite to prevent caries. Japanese scholars' research shows that diabetic patients have a certain relationship with the decrease of vanadium content in the body.
Selenium-deficient human cells will lack self-protection function, so the tissues and organs of the whole body will lack function. Cardiovascular and cerebrovascular manifestations are particularly prominent: cerebral arteriosclerosis is aggravated, cerebral thrombosis and cerebral embolism will also increase, and cerebral arteriosclerosis, cerebral thrombosis and cerebral embolism are usually ineffective; In the acute and chronic inflammatory stage of the liver, due to the lack of selenium, the liver will also lack self-protection function; In the digestive system, due to selenium deficiency, peptic ulcer and celiac disease with unknown causes may occur. At the same time, after selenium deficiency, the immune function of the whole immune system is low, the anti-infection ability is reduced, and even cancer may occur. Seafood, wheat, rice, garlic, mustard and meat are rich in selenium. Therefore, healthy and normal people can generally meet the body's demand for selenium by adjusting their diet reasonably every day.
Excessive cobalt deficiency can cause polycythemia, gastrointestinal dysfunction, deafness and myocardial ischemia.
Fourth, summary.
Trace elements are closely related to human health. Excessive intake, insufficient intake or lack of them will cause different degrees of physiological abnormalities or diseases. The most prominent role of trace elements is closely related to vitality, and only the amount as large or smaller as matchhead can play a huge physiological role. It is worth noting that these trace elements must be supplied directly or indirectly by soil. According to scientific research, up to now, it has been confirmed that there are 18 kinds of essential trace elements related to human health and life, namely iron, copper, zinc, cobalt, manganese, chromium, selenium, iodine, nickel, fluorine, molybdenum, vanadium, tin, silicon, strontium, boron, rubidium and arsenic. Every trace element has its special physiological function. Although they are very rare in the human body, they are necessary to maintain some decisive metabolism in the human body. Once these essential trace elements are lacking, the human body will suffer from diseases and even life-threatening. It has been reported abroad that the reduction of the total amount of iron, copper and zinc in the body can weaken the immune mechanism (disease resistance), reduce the disease resistance, promote bacterial infection, and the mortality rate after infection is also high. Trace elements also play an important role in disease resistance, cancer prevention and longevity.
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