Antioxidants: what they are in simple words, real benefits and harms

Antioxidants and free radicals

Free radicals are molecules that are missing one or more electrons. Every day, every cell in the internal organs is attacked by 10,000 defective compounds. “Traveling” through the body, free radicals take away the desired electron from full-fledged molecules, which undermines human health. Damaged cells cease to function fully, and “oxidative stress” occurs.

The reasons for the appearance of free radicals in the human body are taking medications, radiation, poor ecology, smoking, and ultraviolet radiation.

The consequences of the destructive effects of aggressive oxidants on vital structures are tragic.

Under the influence of free radicals the following develop:

• cancer;
• atherosclerosis;
• heart disease, Alzheimer's, Parkinson's;
• phlebeurysm;
• cataract;
• arthritis;
• asthma;
• phlebitis;
• depression.

Defective compounds cause inflammation in tissues, brain cells, and the nervous system, accelerate aging, and disrupt immune function. They affect DNA, which leads to changes in hereditary information.

To date, no means have been invented to prevent the appearance of free radicals in the body. However, if it were not for antioxidants, a person would get sick much longer, more severely, and more often.

Biological antioxidants intercept the defective molecule, giving it its own electron, thereby protecting the cells of organs and systems from damage. At the same time, the antioxidants themselves do not lose stability after detachment of the negatively charged particle.

The compounds block the oxidative process, promote cleansing, cell renewal, and have a rejuvenating effect on the skin.

Antioxidants are an ecological landing force that stands guard over the human body.

What effect do antioxidants have on the body?

The primary form of antioxidants found in the tissues of the human body are enzymes. They remove reactive oxygen species from the body, turning them into hydrogen peroxide, less active radicals, useful oxygen or water. Vitamins act in the same way; they prevent the body's tissues from being destroyed by free radicals. The difference between the first and second groups of antioxidants is that enzymes are always contained in the tissues of the body, while the supply of vitamins must be replenished through food.

The role of vitamin antioxidants

The largest scavengers of free radicals in the body are vitamins C, , and A.

These antioxidants can be obtained from food, however, due to the highly polluted environment, the human need for these substances increases every year, as a result, it becomes more difficult to compensate for the deficiency using natural sources. In this case, vitamin supplements come to the rescue, which have a beneficial effect on the functioning of internal organs and improve a person’s overall well-being.

The role of antioxidants:

1. Vitamin E (tocopherol). It is embedded in cell membranes, reflects the attack of free radicals, and prevents tissue destruction and damage. In addition, vitamin E slows down peroxidation and stabilizes intracellular processes. Tocopherol stops premature aging of the skin, prevents the development of cataracts, strengthens the immune system, and improves oxygen absorption.
2. Vitamin A (retinol). This antioxidant can be partially synthesized from beta-carotene, which, in turn, mitigates the effects of chemical and radioactive pollution, electromagnetic radiation, and increases the body's resistance to stress. Vitamin A protects the mucous membranes of internal organs and skin from harmful environmental factors, helps the immune system neutralize bacteria and viruses. It destroys carcinogens that cause the growth of malignant tumors, lowers cholesterol levels, and prevents heart disease and strokes. With a chronic lack of retinol, the activity of free radicals increases, dry skin is noted, and vision deteriorates.
3. Vitamin C (ascorbic acid). Protects brain cells and other antioxidants (tocopherol) from free radicals. Vitamin C increases the synthesis of interferon, neutralizes toxins, and stimulates the functioning of nerve cells. Interestingly, one smoked cigarette destroys 100 milligrams of ascorbic acid.

Remember, vitamins by themselves exhibit insufficient antioxidant activity and, without the combined action of minerals, cannot completely protect the body from damaging factors (endogenous and exogenous).

How do antioxidants slow down aging?

Doctors are increasingly convinced that it is antioxidants that slow down the aging of the human body. American scientists are convinced that the higher the content of antioxidants in the body, the higher life expectancy. Observation of mice in whose bodies the production of antioxidant enzymes occurred at an accelerated pace revealed that their life expectancy increased by 20%. In addition, rodents were less likely to suffer from cardiovascular pathologies and age-related diseases.

If we transfer these indicators to a person, then the life expectancy of such people should be 100 years or more. After all, American scientists from the University of Washington confirm the hypothesis that free radicals provoke increased aging of the body. They are associated with cardiovascular, oncological and other diseases that affect human life expectancy.

A joint experiment by Peter Rabinovich and his colleagues on mice revealed that the influence of free radicals on the aging process is great. So, they bred mice in laboratory conditions, in whose bodies they artificially caused an increase in the production of the enzyme catalase. This enzyme works as an antioxidant and promotes the removal of hydrogen peroxide. It, in turn, is a source of free radicals and occurs during their metabolism.

Free radicals disrupt the normal course of chemical processes inside cells and provoke the appearance of new free radicals. As a result, the pathological process is repeated again and again. Antioxidants help break this vicious circle.

The importance of minerals - antioxidants

Macro- and microcompounds enhance the effect of vitamins, have antiallergic, immunostimulating, antitumor, anti-inflammatory, vasodilating and bactericidal properties.

Natural minerals - antioxidants contribute to the healing of body cells, protect membranes from destructive excess oxidation.

Let's look at what organic compounds “protect” the body from harmful radicals:

1. Selenium. This is an element of the glutathione peroxidase enzyme, which supports the health of the heart, liver, lungs, and blood cells. The mineral stimulates the antibody response to painful stimuli (infection) and protects membranes from damage. Selenium is a blocker of redox transformations of metals. A lack of nutrients can cause antioxidants to begin to support free radical processes in the body.
2. Zinc. Promotes the absorption of vitamin A, DNA and RNA repair, maintains normal tocopherol concentrations in the body, protects the human genome from free radicals, keeping it safe and sound.
3. Copper. Normalizes cellular metabolism, is a component of the enzyme superoxide dismutase, which resists aggressive oxidants. A lack of copper in the body leads to a decrease in resistance to colds and ARVI infections.
4. Chromium. Participates in carbohydrate and fat metabolism. Increases the body's reserve capacity, accelerates the conversion of glucose into glycogen, and increases endurance.
5. Manganese. The antioxidant is involved in the production of superoxide dismutase, which protects polyunsaturated fatty acids of cell membranes from attack by free radicals. Manganese improves the absorption of tocopherol, vitamins C and group B.

Powerful natural antioxidants are grapes, blueberries, ginseng, green tea, medicinal mushrooms (meitake, reishi, cordyceps, veselka, shiitake). Despite the abundance of these products on the human menu, people remain defenseless against the destructive effects of free radicals on cells.

According to the Scientific Research Institute of Food Hygiene, today 50% of people are deficient in vitamin A in the body, and 85% are deficient in ascorbic acid and minerals. The culprit is emotional and physical overstrain, which results in increased burning of nutrients, sharp depletion of soils, environmental deterioration, stress, and unbalanced nutrition.

Antioxidants, in the form of dietary supplements, fully cover the body's need for beneficial compounds, protect against oxidants, free radicals, block the formation of nitrosamines, neutralize the harmful effects of lead on red blood cells and the nervous system, increase immunity, destroy cancer cells, and increase life expectancy.

Antioxidants: instructions for use

Most dietary supplements are produced in capsule form - these drugs are the easiest to take. But sometimes antioxidants are found in powder form, which must be dissolved in water or other liquid before use (fresh juices are sometimes used instead of water).

Before use, you need to clearly find out why you need antioxidant drugs. Depending on the purpose of use, dietary supplements with different compositions are better suited. Indications for the use of antioxidants can only be determined by a doctor, but dietary supplements from the brands listed above will not cause harm if used correctly.

The number of doses per day and the duration of the course of administration are the most important elements of the correct intake of biologically active dietary supplements. Unfortunately, it is impossible to list universal rules for all antioxidants, since additives vary too much in composition and effect.

Important! Before using any additive, be sure to read the instructions from the manufacturer. You should not trust any online sources if they indicate different rules for taking dietary supplements.

Daily norm

For the normal functioning of the nervous system and maintaining the health of internal organs, it is recommended to consume daily antioxidant vitamins and minerals in the following dosage:

• zinc – 8 milligrams for women, 11 milligrams for men (if you follow a strict vegetarian diet or raw food diet, the daily intake should be increased by 50% of the indicated dose, since the body absorbs less compounds from plant foods than from animals);
• selenium – 55 micrograms;
• vitamin E – 15 milligrams;
• ascorbic acid – 75 milligrams for women, 90 milligrams for men (smokers are recommended to increase the dosage by 45%, to 110, 125 milligrams, respectively)
• vitamin A – from 1 to 1.5 milligrams;
• copper – 2.5 milligrams;
• chromium – from 100 to 150 micrograms;
• manganese – from 3.0 to 4.0 milligrams;
• beta-carotene – from 3.0 to 6.0 milligrams.

Remember, a person’s daily need for antioxidants depends on the state of health, the presence of concomitant diseases, gender and age of the person.

The best dietary supplements with antioxidant effect

Since antioxidants are a whole group of completely different chemical elements, there are many dietary supplements with antioxidant effects. To purchase an effective and useful drug, you need to pay attention to the brand and the composition of the product. It is better to buy only proven popular brands on specialized websites with dietary supplements or in sports nutrition stores - this ensures the least likelihood of receiving a counterfeit.

The American company Now Foods is considered one of the most reliable brands. It is one of the market leaders in the budget segment of dietary supplements. Now Foods combines high quality and reasonable prices, thanks to which it has many customers around the world. They produce antioxidants in the following forms:

1. Alpha Lipoic Acid
   is a vitamin-like substance with an antioxidant effect that helps neutralize free radicals and produce vitamins C and E.
2. Pyrroloquinoline quinone (PPQ)
   is a B vitamin-like compound that protects mitochondria from free radicals. In addition to pyrroloquinoline quinone, PQQ Extra Strength dietary supplement also contains alpha-lipoic acid.
3. Clinical Strength Ocu Support
   - a comprehensive dietary supplement for eye protection; it contains vitamins A, C, E, B6, B12, zinc, selenium, chromium, taurine and 13 other nutrients.
4. Turmeric & Bromelain
   is another complex dietary supplement designed to remove free radical compounds; The main goal of this dietary supplement is to ensure healthy joints, but it also has a general strengthening effect.
5. Green tea extract (EGCg Green Tea Extract)
   is a supplement containing directly green tea extract and ascorbic acid - both elements have a good antioxidant effect.
6. N-Acetyl Cysteine ​​(NAC)
   is a supplement consisting of three antioxidants: N-Acetyl Cysteine, Molybdenum and Selenium. The first element has the largest percentage in the capsules - this is a sulfur-containing amino acid that protects the protein structures of our body from free radical compounds.
7. Pycnogenol
   is an extract of French maritime pine bark that is a powerful antioxidant that can strengthen the health of the cardiovascular system and the entire human immune system.
8. Curcumin extract (CurcuBrain)
   is an antioxidant that primarily protects cells of the nervous system and thereby improves human cognitive functions.

It is quite difficult to describe all antioxidant preparations, but Now Foods also has the following dietary supplements with antioxidants: Natural Resveratrol, Bromelain, Astaxanthin, Acerola 4:1 Extract Powder, Ubiquinol, curcumin, glutathione, quercetin with bromelain and indole-3-carbinol. But in addition to Now Foods, reliable brands Natrol, Solaray, Solgar, Maxler, Doctor's Best, California Gold Nutrition and others produce antioxidants.

Causes and signs of deficiency

With insufficient intake of antioxidants into the body, people lose clarity of thinking, decrease efficiency, weaken the immune system, deteriorate vision, and develop chronic diseases. Antioxidants speed up the healing process, help increase life expectancy, and reduce tissue damage.

Let's consider the reasons for the depletion of carotenoids, minerals, vitamins in the human body and what enhances the formation of free radicals:

1. Exposure to heat.
2. Stress.
3. Pollution of the atmosphere, water, pesticides, household chemicals.
4. Tobacco smoking.
5. Ultraviolet rays of the sun, radiation.
6. Injuries and wounds.
7. Excessive physical activity.
8. Infection with parasites, viruses, bacteria.
9. Lack of natural antioxidants in the diet.
10. Hypoxia.

Symptoms of antioxidant deficiency in the body:

• apathy;
• dry skin;
• fast fatiguability;
• increased irritability, nervousness;
• decreased visual acuity, sexual function;
• bleeding gums;
• muscle weakness;
• frequent infectious diseases;
• goose bumps on the elbows;
• low performance;
• poor sleep;
• depression;
• loss of teeth, hair;
• the appearance of premature wrinkles, rashes;
• growth slowdown.

In case of individual intolerance to vitamins and minerals - antioxidants, the need for compounds is reduced.

Who benefits from taking Synergin?

Synergin contains antioxidants that penetrate all cells and tissues of the body, as it contains both fat-soluble and water-soluble components. This means that Synergin will act on all fronts and eliminate excess beneficial radicals in the body.

Synergin will be useful:

• For men and women who are about to become parents.
• Men and women during therapy or recovery from infectious diseases.
• Women taking oral contraceptives.
• Women over 45 years old.
• Residents of big cities.

Synergin can be purchased in pharmacies.

Please note that one package of Synergin is enough for 1 month of use.

THIS IS NOT AN ADVERTISING. THE MATERIAL WAS PREPARED WITH THE PARTICIPATION OF EXPERTS.

Excess: why does it occur and how to determine it?

Reasons for increased concentration of antioxidants in the body:

• long-term use of medications high in vitamins E, C, A;
• abuse of foods that have high antioxidant capacity;
• taking the compound for individual intolerance.

Excess natural antioxidants obtained from food do not pose a threat to human health and are easily excreted from the body. An overdose of synthetic antioxidants (vitamin-mineral complexes) can cause hypervitaminosis, which is accompanied by disruption of the functioning of internal organs and systems.

Characteristic signs of excess antioxidants in the body:

• headache, dizziness;
• increased breathing;
• disturbance of visual perception;
• painful sensations in the heart, stomach;
• cramps, spasms;
• fatigue, weakness, apathy;
• muscle pain;
• nausea;
• heartburn;
• digestive disorders;
• insomnia;
• menstrual irregularities (in women);
• skin irritation;
• increased intracranial pressure;
• joint pain.

Despite the undeniable benefits of antioxidants, excess amounts of synthetic compounds in the body cause harm to the body.

An overdose leads to the formation of kidney stones, gall bladder stones, heart problems, adrenal atrophy, damage to white blood cells, allergic reactions, and enlargement of the liver and spleen. To avoid these consequences, strictly control the level of consumption of synthetic vitamins, minerals - antioxidants.

Antioxidant vitamins in the prevention and treatment of cardiovascular diseases

About the article

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Regular issues of "RMZh" No. 11 dated June 11, 2005 p. 780

Category: General articles

Authors: Polosyants O.B. , Aleksanyan L.A.

For quotation:

Polosyants O.B., Aleksanyan L.A. Antioxidant vitamins in the prevention and treatment of cardiovascular diseases. RMJ. 2005;11:780.

Why does a person grow old, what is the cause of his fatal diseases? These questions have always worried scientists of various specialties all over the world, and only now the veil of secrecy over some of them began to be lifted.

It has been established that one of the important processes occurring in the body associated with the functioning and damage of cells is determined by the so-called free radicals. For many years their existence was denied, and only with the development of more subtle and advanced research methods was their role in the body demonstrated, which sometimes turned out to be quite dramatic. In the early 70s of the last century, several works were published on free radicals, the mechanism of their formation, the problem of aging and the importance of free radical oxidation, which laid the foundation for the study of both the role of free radicals and substances that block their activity, called antioxidants. Then the scientific nomenclature included such terms as free radical, oxidative stress, free radical cascade, peroxidation, antioxidants, antioxidant protection. A free radical is a particle, atom or molecule that has one or more unpaired electrons in its outer shell. This makes radicals chemically active, since the radical seeks to either regain the missing electron by taking it away from surrounding molecules, or get rid of the “extra” electron by giving it to other molecules [8]. The most common source of free radicals in the body is oxygen, which is widely used by the body during respiration, in its normal state, the nucleus of which is surrounded by 8 paired electrons. Chlorine and nitrogen molecules can also act as sources of free radicals. Free radicals are formed in the body as a result of many redox reactions. The physiological role of free radicals is the transfer of electrons by flavins, necessary for the renewal of the phospholipid layer, cell membranes, they are integral components of the oxidative phosphorylation reaction in mitochondria, mitogenesis, they are necessary for signal transmission in the processes of intercellular interaction and in the processes of lipid peroxidation, arachidonic acid and docosohexaenoic acid. acids necessary for the implementation of natural cytotoxic reactions. Some of them, in particular, superoxide, hypochloric acid and nitrogen monoxide, have bactericidal and antitumor effects, and nitric oxide, in addition, is a specific factor for vascular relaxation. The regulatory functions of free radicals in a healthy person can be transformed into their damaging effects, primarily when their quantity changes [10]. The number of “extra” free radicals not involved in physiological processes in the body progressively increases with age, with physical activity, with sudden changes in temperature, various types of radiation, with infections and intoxications (for example, alcohol), during such physiological and pathological processes , such as apoptosis, inflammation, immune response. Among the external factors that actively convert stable oxygen into a free radical can be ultraviolet radiation, combustion products formed during smoking, human industrial activity, many chemicals, etc. Trying to compensate for the loss of an electron, the free radical takes it away, for example, from a molecule that is part of the bilayer of the cell membrane, turning it into a new free radical, the so-called secondary one. Subsequently, a pathological chain reaction occurs that violates the integrity of cells and causes their death, called the free radical cascade and determining the so-called oxidative stress. The destructive effect of free radicals manifests itself in accelerating the aging process of the body, provoking inflammatory processes in various tissues and systems of the body, including cells of the brain, heart, hematopoietic, immune system and many others. Currently, the role of free radical oxidation in the pathogenesis of diseases such as atherosclerosis, Alzheimer's disease, angiopathy in diabetes mellitus, degenerative diseases of the joints and spine, cataracts, some types of malignant tumors, and systemic diseases has been proven. The constant formation of free radicals during the aging process of a person leads to a decrease in the functional activity of his organs [10,11]. The mechanism of damage caused by free radicals may vary in different pathologies. Thus, in atherosclerosis, lipid peroxidation (LPO) becomes more important, in degenerative diseases - damage to proteins, and in carcinogenesis, the leading factor is the structural disruption of DNA and RNA nucleic acids. Naturally, in all cases, the processes of peroxidation do not occur in isolation, and a sharp activation of one of the directions affects the others - like a chain reaction. Nevertheless, it can be said that in various diseases, various links in the free radical oxidation process will have a leading role in the development of pathological changes, and certain substances will be more effective, the targets of which are precisely those links to which they have a greater affinity [11]. An antioxidant is understood as a chemical substance that can, in low concentrations, reduce or completely stop free radical oxidation in tissues [3]. The antioxidant neutralizes the free radical by donating its own electron, thereby breaking the chain reaction. By interacting with free radicals, antioxidants themselves become oxidized, so-called tertiary radicals, and can no longer perform their functions, so the supply of antioxidants must be constantly replenished. The body has a natural antioxidant system consisting of antioxidant enzymes: superoxide dismutase, which binds reactive oxygen species to form hydrogen peroxide; catalase, which destroys peroxides into lipid hydroperoxides, glutathione peroxidase, which reduces lipid hydroperoxides due to the oxidation of glutathione, glutathione reductase, which reduces glutathione by oxidizing NADPH (the latter is reduced through the cytochrome chain). The body's endogenous antioxidant system, controlling the damaging effects of free radicals, plays a huge role in normalizing metabolic processes, maintaining natural metabolic balance. In addition to it, there is a system of natural antioxidants, represented primarily by vitamins (tocopherol, vitamin A and carotenoids, ascorbic acid), flavonoids - natural plant pigments, ubiquinone, etc. Artificial substances - antioxidants - are also synthesized, the activity of which is sometimes many times higher than the activity natural antioxidants (probucol, dibunol, acylcysteine, emoxypine, dimethyl sulfoxide, selenium compounds) [4,10]. One of the most discussed topics on oxidative stress and the protective role of antioxidants is lipid peroxidation in the development of atherosclerosis. Large epidemiological studies have established a connection between low levels of natural antioxidants in the body and a significant increase in the risk of cardiovascular diseases. Experimental studies of the process of atherogenesis have established the role of free radical oxidation in the process of formation of atherosclerotic plaque. The literature presents many studies - from studying the chemistry and enzymology of the oxidation process of low-density lipoproteins (LDL) in vitro, the biological effects of oxidized LDL in cell culture and in laboratory animals, to determining the role of antioxidants in atherosclerosis in humans in large multicenter studies [2]. It is known that during lipid peroxidation, so-called modified (oxidized) LDL are formed, which are poorly recognized by hepatocyte receptors and do not participate in the normal physiological pathway of LDL catabolism. Oxidized lipoproteins are captured by macrophages, which are transformed into foam cells, which, when destroyed, release lipid crystals that are part of atherosclerotic plaques. In addition, modified LDL causes damage to the vascular endothelium, triggering a cascade of pathological reactions on the part of the vascular wall. In addition, factors associated with the antioxidant system, such as damage to the vascular endothelium by free radicals, impaired hemostasis, its shift towards hypercoagulation, changes in platelet mobility, and immune disorders, may play a role in atherogenesis. The increased development of such a risk factor as arterial hypertension is also important. The decrease in the synthesis of endogenous nitric oxide that occurs during oxidative stress due to its binding by secondary lipid radicals reduces endothelium-dependent vasodilation, while not only an increase in blood pressure occurs, but also the activity of many antihypertensive and antianginal drugs decreases [5,7,9,12]. In experimental models, it was shown that the simple addition of antioxidants to blood plasma increases the stability of HDL, and in cell culture there is a decrease in lipid accumulation, macrophage migration and a decrease in the proliferation activity of intimal cells. Experiments on animals have shown the ability of antioxidants to prevent the development of experimental atherosclerosis and stabilize existing atherosclerotic changes in blood vessels. These data pave the way for studying the effects of antioxidants in humans. Currently, there are many different studies on the use of various natural and synthetic antioxidants, the results of which are far from clear. Table 1 lists several studies showing the beneficial effects of antioxidants. It can be seen that despite the seemingly positive results, the expected and actual effects differ significantly. Thus, virtually no studies show a reduction in the incidence of fatal myocardial infarction and other fatal endpoints, and there is no effect in women. In other clinical studies, the therapeutic and preventive effect of antioxidants was even more modest [4]. With what it can be connected? Several reasons can be considered. Firstly, the effect of antioxidants on atherosclerosis is mainly preventive. And since the process of formation of an atherosclerotic plaque begins in youth, during its formation and the manifestation of coronary artery disease it is unlikely that significant success can be achieved using means that primarily affect the early pathological stages. Secondly, as has already been proven, there is an entire antioxidant system with its own easily disturbed balance. The use of one or more exogenous antioxidants can upset the balance, and most likely for the worse. As a third reason, genetic defects leading to fermentopathy in the body's antioxidant system cannot be ruled out. In this case, the existing disorders simply cannot be eliminated by the drugs that we use due to the specificity of these disorders. So to use or not to use antioxidants? Despite everything, most scientists still recommend using them as preventative agents from an early age, in addition to other medications for the development of diseases, as one of the components of a healthy lifestyle. Among the many antioxidants that differ in their mechanism of action, origin, points of application, chemical structure, etc., from a practical point of view, natural exogenous antioxidants—vitamins—are of great interest due to their availability, prevalence in nature, better study and proximity in essence to the body person. Almost 450 years have passed from the discovery of vitamins to the study of their mechanism of action, their role in homeostasis and understanding of their importance in the oxidative defense of the body. And now their role in the development of atherosclerosis, carcinogenesis, and the differences in their effects in experiments and clinical studies are not completely clear. Currently, vitamins A, E and ascorbic acid have proven antioxidant activity among vitamins. Vitamin A is a fat-soluble vitamin that, together with other carotenoids, provides a powerful natural antioxidant defense for the body. There are varieties of vitamin A, the most physiologically important of which is vitamin A1, which has several precursors - a, b and g-carotenoids, among which b-carotene has the greatest vitamin and antioxidant activity (by the way, it does not give symptoms of hypervitaminosis). The mechanism of action of vitamin A and b-carotene as antioxidants is to participate in the exchange of thiol compounds, inhibit the conversion of sulfhydryl groups into disulfide groups, and normalize the functional and structural properties of membranes. According to the membrane theory of action of vitamin A, retinol is able to penetrate into the hydrophobic zone of biomembranes and interact with lecithin-cholesterol monolayers at the phase boundary, causing restructuring of cell membranes, lysosomes and mitochondria. b-carotene performs antioxidant functions due to the presence of isoprenoid sites in its formula. Vitamin A is widely distributed. The liver of cattle and pigs, egg yolk, whole milk, butter, sour cream, liver of sea bass, cod, and halibut are especially rich in it. Vegetables and fruits colored red and orange (carrots, tomatoes, peppers, etc.) are rich in carotenoids. The recommended antioxidant dose of vitamin A is from 3300 to 5000 IU, but large doses can lead to symptoms of hypervitaminosis; consumption of b-carotene is advisable in doses corresponding to the upper level of physiological norms (6–10 mg/day). Vitamin E - there are several chemically different compounds related to tocopherols, of which a-tocopherol has the greatest biological activity. It is found in the membranes of living cells. Its natural sources can be cereals, cold-pressed vegetable oils, green parts of plants, and caviar. Vitamin E activates the synthesis of heme and hemoglobin, myoglobin, catalases, peroxidases, tissue respiration enzymes - coenzyme Q and cytochromes, including cytochrome P-450. It controls not only energy (energy formation in mitochondria), but also synthetic processes in tissues. Due to its lipophilicity, the tocopherol molecule is able to integrate into the lipid layer of cell membranes and thereby exert a membrane-protective and membrane-stabilizing effect, maintaining the functional stability of the outer plasma membrane of the cell, including erythrocyte membranes, lysosome membranes, helps normalize tissue respiration in mitochondria, stabilize cell enzyme systems that interfere with activity FLOOR. When interacting with lipid peroxide radicals, vitamin E reduces them to hydroperoxides, turning into a tocopherol-quinone complex excreted by the kidneys. Vitamin E is the most potent natural antioxidant, playing an incompletely understood role in selenium metabolism. By binding to polyunsaturated fatty acids (primarily arachidonic acid) in biological membranes, vitamin E prevents the formation of prostaglandins, reducing inflammatory reactions. The reducing agent for the antioxidant properties of tocopherol is ascorbic acid. The potentiation of the antioxidant effect of a-tocopherol when combined with ascorbic acid, retinol, flavonoids and selenium preparations has been experimentally and clinically observed. With vitamin E deficiency, a pronounced development of atherosclerosis and premature aging is noted. Thus, an inverse correlation between the amount of tocopherol in the diet and the incidence of coronary artery disease and fatty hepatosis was noted. Studies in patients with various forms of coronary artery disease have revealed the most clear trend towards a decrease in the plasma levels of vitamins E and A in patients with acute coronary syndrome and less pronounced in patients with stable angina. These data demonstrate increased oxidation and lower antioxidant activity in these conditions. The dosage of vitamin E as an antioxidant is 400–800 IU and can be safely increased if necessary. Vitamin C (ascorbic acid) is a water-soluble vitamin widely found in nature. Vitamin C is involved in almost all types of metabolism; its biosynthesis is carried out by plants and most animals, with the exception of humans and other primates. Ascorbic acid is found in significant quantities in products of plant origin: citrus fruits and other fruits and berries, rose hips, cabbage, pine needles, etc.; however, it is easily destroyed during cooking and storage, which may lead to its deficiency. For medical purposes, vitamin C is obtained synthetically. Ascorbic acid is a unique vitamin and a unique antioxidant, since being water -soluble easily penetrates all the tissues, many reactions occurring with its participation are reversible, it actively interacts with other antioxidants and vitamins in metabolism. Vitamin C, together with its metabolite - dehydroacorbic acid, forms an oxidizing and restorative system that transports hydrogen ions. Ascorbic acid is involved in the synthesis of collagen, hyaluronic acid, steroid hormones, norepinephrine, carnitine, iron absorption from the intestines and its inclusion in gem, activation of metal -focuses, the formation of vitamin D active metabolites, being its synergist. Vitamin C is able to increase the amount of nitrogen oxide in endothelia, preventing its destruction and increasing its synthesis [6]. Vitamin C, interacting with tocopherol and glutation, is one of the leading components of the biological antioxidant system. The stimulating effect of vitamin C on the activity of the cytochrome P -450 - a key enzyme of hydroxylation and peroxide oxidation is proved. Vitamin C in the form of Ascorbata -Ion is the most important endogenous antioxidant of blood plasma, it protects lipids from oxidation with peroxidal radicals. Vitamin C refers to immediate antioxidants, which is called a "trap of radicals." In addition, ascorbic acid prevents the oxidation and destruction of other important antioxidants - vitamins E and A. High concentrations of ascorbic acid are determined in metabolically active organs and tissues: adrenal glands, lens, cornea, kidneys, brain, pancreas, as well as in thrombotcytes and leukocytes [1]. Regarding the doses of ascorbic acid, there is no unequivocal opinion. It is known that one of the propagandists of its application as a means of extending life L. Polling recommended dose up to 10 g per day. Academician of the Academy of Medical Sciences of the USSR A.L. Myasnikov also advised to take ascorbic acid in large doses (2-3 g) per day for the prevention and treatment of atherosclerosis. However, these doses, as you know, can have a toxic effect on the pancreas, contribute to the formation of stones in the urinary tract, and show the effect of hypercoagulation. Therefore, the WHO committee introduced the concept of an unconditionally permissible daily dose of vitamin C, which does not exceed 2.5 mg/kg of body weight, which with an average weight of 80 kg is 200 mg. This dose by many doctors seems optimal for preventive and antioxidant purposes. The market currently presents a drug containing 200 mg of ascorbic acid - asvitol (pharmaceutical, Russia) in the form of hardening tablets (included in a new list of drugs of preferential leave). Asvitol is indicated for the use of both preventive purposes and as part of the complex therapy of diseases of the gastrointestinal tract, cardiovascular system, pathologies of the respiratory system, prolonged infectious diseases. For adults, for the purpose of prevention, 1 tablet is prescribed 1 time per day; For therapeutic purposes - 1-2 tablet 1-2 times a day. The duration of administration depends on the nature of the disease. Literature 1. Carr, A. C, Frei, B. Toward a New Recommoded Dietary Allowance for Vitamin with Based on Antioxidant and Health Effects in Humans. // am. J. Clin. Nutr.– 1999.– Vol. 69.– P. 1086–1107. 2. Chisolm GM, Steinberg D. Oxidative Modification Hypothesis of atherogenesis: an overview. // Free Radic Biol Med.– 2000.– Vol. 28 (12) .– p.1815–1826. 3. Halliwell B., Gutteridge JM The Antioxidants of Human Extracellular Fuids. //Arch. Biochem. Biophys.– 1990.– Vol. 280.– P. 1–8. 4. Kris --etherton pm, lichtenstein ah, Howard BV, et al. Antioxidant Vitamin Supplements and Cardiovascular Disease. //Circulation.– 2004.– Vol. 110.– P. 637–641. 5. Levy Ap, Friedenberg P., Lotan R., et at. The Effect of Vitamin Therapy On the Progression of Coronary Artery Atherosclerosis Varies by Haptoglobin Type in Postmenopausal Women // Diabetes Care.– 2004.– Vol. 27.– P. 925–930. 6. Padayatty, SJ, Katz, A., Wang, Y., ECK, P., Kwon, O., Lee, J. - H., Chen, S., Corpe, C., Dutta, A., Dutta , S. K, Levine, M. Vitamin C as an Antioxidant: Evaluation of Its Role in Disease Prevention. //J. Am. Coll. Nutr.– 2003.– Vol. 22.– P. 18–35. 7. Steinberg D., Witztum Jl is the Oxidative Modification Hypothesis Relevant to Human Atherosclerosis? Do the antioxidant trials conducted to data refuse the Hypothesis? //Circulation.– 2002.– Vol. 105.– P. 2107–2111. 8. Vladimirov Yu.A. Free radicals and antioxidants. Bulletin of the Russian Academy of Medical Sciences. - 1998.– No. 7.– S. 43–51. 9. Golikov A.P., Boytsov S. A., Mikhin V.P., half -magicians V. Yu. Free radical oxidation and cardiovascular pathology: correction with antioxidants. // attending physician. - 2003.– No. 04. 10. Zaitsev V.G., Ostrovsky O.V., Zakrevsky V.I. The relationship between the chemical structure and the target of the action as the basis for the classification of direct -action antioxidants. // Experience. wedge. Pharmacac. - 2003.– T.66.– No. 4.– S.66–70. 11. Captured S.V. Clinical pharmacology of antioxidants. // Farmindex: Practice. - 2001. - Issue 5. 12. Free -radical oxidation and antioxidant protection in diabetes. A manual for doctors. Edited by the director of the ENC RAMS Academician RAMS Professor I. I. Dedov, Moscow, 2001.

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Natural springs

The greatest amount of antioxidants is concentrated in fruits and vegetables of bright colors - red, orange, yellow, purple, blue.

To get the maximum amount of nutrients and biological antioxidants, these foods should be eaten raw or lightly steamed.

Any heat treatment (boiling, frying, baking) of fruits and vegetables for 15 minutes or more kills beneficial compounds and reduces the nutritional value of the product.
Table No. 1 “Antioxidant capacity of products”

According to research from Boston University in the USA, plant products, in particular spices, exhibit the greatest antioxidant capacity.
Table No. 2 “Ten best antioxidant foods”

Other natural sources of antioxidants: tomatoes, pumpkin, carrots, grapefruit, nectarines, persimmons, apricots, mangoes, peaches, papaya, strawberries, zucchini, whole grains, freshly squeezed juices from pomegranate, grapes, apples, cherries, chokeberries.

These products neutralize free radicals, increase immunity, activate enzyme activity and reduce the risk of developing degenerative diseases.

Negative effects of antioxidants

Antioxidants (like any biologically active compounds) should be prescribed only after appropriate laboratory and/or instrumental diagnostic methods have been carried out and certain indications for their use have been identified. Of course, this applies to a greater extent to additives and medications: those compounds contained in food products, during the process of enzymatic breakdown and exposure to certain conditions in the gastrointestinal tract, are not completely absorbed due to partial destruction.

It is also necessary to take into account their pharmacokinetics: for example, we have already written earlier that vitamins A and E, which have a fat-soluble nature, should be prescribed only under the supervision of tests and not for a long period. Otherwise, this is fraught with their accumulation.

The symptoms of hypo- and hypervitaminosis are often similar, which makes their differentiation somewhat difficult. Below we will present several signs that accompany excessive intake of tocopherols and retinol into the body, and will try to demonstrate that sometimes antioxidants (if used incorrectly and/or not indicated) have significant side effects.

Excess vitamin A leads to:

• nausea;
• vomiting;
• migraine;
• visual impairment;
• liver damage;
• alopecia;
• congenital fetal defects.

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Tocopherol hypervitaminosis is associated with:

• nausea;
• diarrhea;
• bleeding.

In addition, it is necessary to take into account the effect of some antioxidants on microsomal liver enzymes that carry out the first phase of detoxification. So, say, grapefruit juice can suppress the work of CYP3A4

- cytochrome, which converts estrogens into a very proliferative 16-OH-estrone.
On the other hand, curcumin inhibits the activity of SUZ1A2
, which metabolizes coffee and some drugs.

Medicines – antioxidants

Unfavorable environmental conditions, bad habits (smoking), and work in hazardous industries cause an increased need for antioxidants in the body.

As a result, natural biological antioxidants supplied with food become insufficient, which leads to depletion of carotenoids, minerals, and vitamins. In order to prevent a deficiency of beneficial nutrients in the body, the use of synthetic forms of the compound (in tablet or capsule form) becomes necessary.

The most useful medicinal antioxidants:

1. Lipin. Belongs to the category of natural phosphatidincholines. It exhibits a pronounced antihypoxic effect, increases the rate of oxygen tissue diffusion, and stimulates the activity of epithelial cells. Lipin inhibits the peroxidation of triglycerides in tissues and blood plasma, and acts as a detoxifying agent. It is used as an immunomodulatory drug that can affect general metabolism and the digestive system.
2. Coenzyme Q10. This is a coenzyme that has strong antioxidant activity and optimizes the process of oxidative phosphorylation. Thanks to these properties, coenzyme Q10 improves the energy supply to cells. In addition, the drug restores the activity of tocopherol to fight free radicals and helps neutralize their harmful effects on the body. As a result, the substance protects DNA and cell membranes from damage. Ubiquinone, which is part of the coenzyme, slows down the aging process and activates blood circulation.
3. Glutargin. The compound is a combination of glutamic acid and arginine salt. The main role of the drug is to neutralize and remove toxic ammonia from the human body. Glutargin has hepatoprotective properties and has antihypoxic, membrane-stabilizing, antioxidant effects. Used to relieve symptoms of alcohol intoxication and treat liver diseases.
4. Dibikor, Kratal. The drugs exhibit stress-protective, hypoglycemic, neurotransmitter, antioxidant and antiarrhythmic effects on the body. They improve myocardial contractility, reduce blood pressure, eliminate mood lability, and manifestations of intoxication with cardiac glycosides. Recommended for use in heart failure, endocrine disorders, vegetative neuroses, and treatment of neurocirculatory dystonias.
5. Asparkam, Panangin. The drugs contain potassium and magnesium, which regulate metabolic processes in the human body, providing an antiarrhythmic effect. They help restore electrolyte balance. Asparkam is involved in muscle contractions, transmission of impulses along nerve fibers, RNA synthesis, and maintaining normal heart function. It is part of the DNA structure, stimulates the intercellular synthesis of phosphates, and prevents excessive release of catecholamine during stress. Panagin triggers the motility of the digestive tract, promotes the penetration of potassium and magnesium ions into the intracellular space, and strengthens the immune system. The drugs are used to treat ventricular extrasystole, coronary insufficiency and cardiac arrhythmia, caused by electrolyte disturbances, digitalis drug intoxication. In addition, panangin and asparkam are prescribed as an adjuvant for shock, coronary heart disease, hypokalemia and hypomagnesemia, and chronic circulatory failure.
6. Essentiale. The active substance of the drug is essential phospholipids, which are similar in chemical structure to endogenous membrane phospholipids. However, they surpass them in their functional properties due to the high level of linoleic acid in the composition.

Phospholipids are the main structural element of cell membranes, organelles. The compounds are involved in cell division, regeneration, and differentiation. Essentiale improves membrane function, biological oxidation, ion exchange, intracellular respiration. In addition, the drug affects oxidative phosphorylation in the energy metabolism of cells, increases the detoxification ability of the liver, and restores membrane-bound enzyme systems.

Thus, free radical oxidation substrates (lipin, essentiale), biooxidants (coenzyme Q10) and drugs of peptides, nucleic acids, amino acids (glutargin, panangin, asparkam, dibikor, kratal) exhibit powerful antioxidant properties, protect, reactivate cells from damage and have a strong immunomodulatory effect. action.

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Antioxidants from freshly squeezed juices

Antioxidants from freshly squeezed juices are the same antioxidants from food, but in much higher concentrations. One glass of juice is enough to satisfy the body's daily need for various antioxidants. Such a volume cannot be obtained by consuming raw vegetables and fruits, since a person simply physically cannot eat them in such quantities (meaning, in their raw form). In addition, most vitamins and minerals are destroyed during heat treatment of food products, and freshly squeezed juices are not subject to any heat treatment.

It is healthy to drink almost any freshly pressed juice: berries, fruits and vegetables. Naturally, the higher the level of antioxidants in a fresh vegetable or fruit, the higher their concentration will be in fresh juice.

Dark berries contain a record amount of antioxidants. The leader among vegetables is beets (which can only be drunk in combination with other juices, for example, carrot).

Do not overuse fruit juices, as they greatly increase blood sugar levels and stimulate the production of the hormone insulin!

Antioxidant-rich foods[edit | edit code]

Antioxidants in foods and supplements (equivalent content)
Antioxidants are primarily found in various fresh fruits, as well as in products made from them (freshly squeezed juices, infusions and tinctures such as iced tea, fruit juice, etc.). Antioxidant-rich fruits include: blueberries, grapes, cranberries, rowan, chokeberry, currants, and pomegranates. All of them have a sour or sweet-sour taste and a red (reddish-blue, blue) color. The Brazilian (South American) acai fruit is a champion among other well-known antioxidant fruits: acai contains 10 times more antioxidants than cranberries. Among the drinks, red wine, green tea and, to a lesser extent, black tea stand out.

Content

• 1 Antioxidants 1.1 Mechanism of action

Efficacy studies[edit | edit code]

Do antioxidant supplements help improve performance and/or recover faster?

Almost all studies examining the effects of antioxidant supplements on athletic performance have found no benefit. Thus, vitamin E has been shown to have no effect on the endurance of swimmers, professional cyclists, marathon runners, student-athletes and sedentary people. Additionally, studies using vitamin E complex, vitamin C, coenzyme Q10, and other vitamins and mineral salts have also found no effect on the performance of runners, triathletes, soccer players, endurance athletes, and ultra-endurance athletes.

Moreover, some studies have shown that antioxidant supplements may be harmful for athletes. Vitamin E has been shown to reduce muscle strength, vitamin C has been shown to slow down the speed of running dogs and impair the effectiveness of exercise. Additionally, because they reduce the production of ROS (reactive oxygen species), vitamin C supplements interfere with the recovery process after exercise, which can have a negative impact on future athletic performance.

Various studies have produced conflicting results regarding the effects of antioxidant supplements on recovery processes.

Some researchers have reported that supplementing with vitamin C and/or E may protect cells from exercise-induced damage, reduce the inflammatory response to exercise, and prevent the loss of muscle strength. However, other studies have found no significant effects of antioxidant supplementation on markers of muscle damage, inflammation, and post-exercise muscle soreness. It is likely that the increased amount of ROS generated in the days after intense exercise is not involved in the mechanisms of decreased muscle function and muscle soreness. On the contrary, ROS may play an important indirect role in the repair and protection of cells from future damage.

This may mean that the use of antioxidant supplements during this period may limit the body's adaptation to physical activity. This is an interesting area for future research.

Do antioxidant supplements improve the health of athletes?

Although there is evidence that consuming antioxidant supplements can reduce exercise-induced oxidative stress, there is no evidence to support the health benefits of such supplements. An important issue in this discussion is the difficulty of determining the level of oxidative stress and then interpreting the results of these measurements in relation to human health. Indeed, measuring oxidative stress is a difficult process that is not universally available. For example, a doctor cannot request a measurement of oxidative stress levels in the clinical department of his hospital. Such measurements are usually carried out in research laboratories. Such studies involve a variety of techniques that assess the level of oxidative stress. These include measuring the concentration of by-products of lipid, protein and DNA oxidation, as well as assessing the body's antioxidant capacity. There are also doubts about the accuracy and reliability of many of these techniques. In addition, the use of oxidative stress biomarkers is not universally accepted. Most prospective studies examining the relationship between oxidative stress levels and disease onset have not shown a strong association between the two. So while antioxidants may reduce exercise-induced oxidative stress, we don't currently know whether this will provide future health benefits.

Two recent studies have shown that antioxidants may suppress the health benefits of exercise. Ray et al (2009) demonstrated that a combination of vitamins C, E, and α-lipoic acid blunted the beneficial effects of exercise on vasodilation (vasodilation) and blood pressure reduction in older adults with moderate hypertension. Ristous et al (2009) found that supplementation with vitamins E and C had a negative effect on the beneficial effects of exercise on insulin sensitivity. Given that blood pressure and insulin sensitivity are risk factors for cardiovascular disease, these studies showing that antioxidants reduce the benefits of exercise fall far short of proving that antioxidants are beneficial for athlete health. These two studies provide the strongest arguments against the use of antioxidants in sports, positioning them as beneficial dietary supplements for athletes.

Current recommendations for optimizing nutrition

In summary, there is currently insufficient evidence to recommend antioxidant supplementation for athletes who consume recommended amounts of dietary antioxidants in their daily diet. Antioxidant supplements do not improve physical performance. There is evidence that they may be beneficial in post-workout recovery, although more research is needed in this area. There is also no evidence to suggest that antioxidant supplements will benefit an athlete's health. Moreover, we have research evidence that antioxidants can seriously interfere with health-promoting processes in which ROS are involved, such as lowering blood pressure and increasing insulin sensitivity, so it would be prudent to use antioxidant supplements with caution. Physically active people should optimize your food. They should consume foods rich in natural antioxidants, such as fruits, vegetables, whole grains and nuts. The listed products, unlike tablets and capsules, contain antioxidants in the required quantities and proportions. They also work together to optimize the antioxidant effect.

Antioxidant supplements may be needed in situations where a person is unable to supplement their diet with dietary antioxidants. In such cases, a person may have a specific diet that can lead to a deficiency of antioxidants in the body. And since there are currently no adequate laboratory tests to determine antioxidant requirements, a qualified sports nutritionist can provide some assistance.

Source:

Peternelj TT, Coombes JS. Exercise and oxidative stress: Is antioxidant supplementation beneficial? Sport Health. 2009, vol.27, no.2, pp.25-28.