Nutrition of pregnant women
What are antioxidants?
Nutrition of pregnant women
Before the scientific revolution of the beginning and the middle of the 20th century, the population of the Earth lived relatively calmly, taking conception, birth, health, illness and aging as some kind of natural reality.
Elena Bondareva Biologist, Moscow
But after in the 1950s the Soviet academician N.N. Semenov received the Nobel Prize for the discovery of the so-called free radicals, the world literally went mad: almost every day scientists discovered new properties of free radicals, gradually moving away from pure chemistry to physics, biology and, most importantly, to medicine. Over the years, people have learned that the aging of the skin, the development of cancer, and sometimes infertility are associated with these aggressive structures.
At present, free radicals are considered as defective molecules that are deprived of one electron and are trying in every possible way to return it, taking away from other, "normal" molecules. From the "normal" molecules, all cells and tissues of the body are built, so when free radicals attack them, they oxidize (that is, they give their "native" electrons to "hungry" radicals) and trigger an irreversible process of tissue destruction.
Taking away the covenant electron from a normal molecule, the free radical turns into a stable compound, and the attacked molecule becomes a free radical. Each time more and more cells are affected, and the circle closes. As a result of free radical oxidation, molecules that used to be inert enter chemical reactions. For example, collagen molecules, when encountered with oxygen radicals, become so active that they are able to communicate with each other. Cross-linked collagen is less elastic than normal collagen, and the accumulation of such collagen dimers leads to skin aging, wrinkles.
The most obvious example of the reaction of free radical oxidation is the corrosion of metals. Under the action of free radicals, the human body also gradually "rusts" and wears out.
From cause to effect
Free radicals are constantly produced in the cells of the body under the influence of various factors. Earlier, the way of their formation under the influence of radiation radiation was established, but today in the areas that are safe in terms of the radiation level this reason goes to a secondary plan.
Another reason, not the most common among young and healthy people, is the formation of free radicals in the use of medicines. Exposing all possible enzymatic transformations in the body, the molecules of some drugs lose their electrons in these chemical reactions, turning into free radicals.
The influence of smoking is also widely discussed: nicotine and tar affect the cells of the body, triggering a number of free radical reactions.
However, the most common reasons for the formation of free radicals today are poor ecology, ultraviolet radiation and stress.
Tens of thousands of aggressive chemical molecules that pollute the environment get into the body when breathing, with food or through the skin, and it is impossible to protect themselves from their penetration in any physical way.
Our favorite sun, which brings joy to the warmth and beauty of a matt tan, is in fact almost the main "enemy" of the human body.
After all, ultraviolet rays cause the very photo-aging, which doctors and manufacturers of "sunburn" means so much in recent years have been talking about. The ultraviolet radiation of the sun penetrates into the skin cells, while it is so powerful that it literally knocks out electrons from the molecules that form the cell membranes and the internal environment of the cell. As a result, the "native" molecules are converted into radicals and begin to act against the host organism according to the mechanism described above.
It was also proved the powerful influence of stress on the activation of free radical processes. Hormones of stress, adrenaline and cortisol, in adverse life situations are produced in increased amounts, disrupting nutrition and normal breathing of the cell, which immediately leads to the accumulation and spread of radicals throughout the body. Aging and physiological deterioration of the body are the main consequences of free radical reactions.
Radicals and pregnancy
Naturally, speaking about the general danger of exposure to free radicals on the body, scientists could not avoid this problem in pregnant women, on whose health the future of a whole generation of children depends. As a result of the research, the following peculiarities of the formation of free radicals and their influence on the mother's organism and future child.
Immediately after conception, a powerful hormonal reconstruction occurs in the woman's body. "Without waiting" for such changes, tissues and organs experience a certain stress, as a result of which the number of free radicals sharply increases, attacking, among other things, the cells of the placenta and embryo.
The increase in the number of free radicals during pregnancy is associated with various causes:
- free radicals participate in the processes of synthesis of progesterone - a hormone responsible for the preservation and normal course of pregnancy. For the synthesis of progesterone in large quantities, more free radicals are needed;
- during pregnancy in a lack of calcium, the process of utilization of metabolic products in the cell is disrupted and, as a consequence, the concentration of free radicals increases;
- Excessive and uncontrolled enthusiasm for iron preparations can also cause an increase in the number of free radicals.
An increase in the number of free radicals during pregnancy would certainly lead to miscarriages if nature did not program a special "anti-radical" mechanism called the antioxidant system (AOC), whose mechanism of action is aimed at blocking the oxidation of cellular molecules by free radicals. The AOS contains a number of enzymes and substances that, as a result of a whole sequence of reactions, destroy free radicals. Antioxidants are the first to "meet" the radicals, contact them and give them their electrons, thus rendering them harmless. At the same time, the structure of antioxidants remains stable - they do not turn into radicals (as any other molecules would do).
Thus, as the number and activity of free radicals increase, the activity of the antioxidant system increases proportionally. There seems to be nothing to worry about; the body protects itself. However, unfortunately, AOS resources are not unlimited, and with excessive radical activity, they are quickly depleted and become insolvent. What can this lead to? The data indicate that excessive peroxidation can cause a premature pregnancy resolution.
The truth is somewhere near
Doctors for a long time have found a way of purposeful struggle against excessive oxidation by means of special substances - antioxidants, additionally entering the body with food or as part of special multivitamin complexes. Antioxidants give their radicals an electron, while remaining stable compounds. Thus, the continuous chain of destruction of molecules ceases.
The most important antioxidants for future mothers are the vitamins A, E and C known to everyone, as well as the widely studied mineral-selenium. All these components are included in the AOC.
Vitamin A. This name generalizes several groups of compounds; retinoids and carotenoids. Differences between them are associated, mainly, with completely different sources of intake and "places of application".
Retinoids enter the body mainly with animal food and freshwater fish. They are also found in optimal amounts in eggs and dairy products. In this case, the more foods contain fat, the higher the concentration of retinoids in them.
Retinoids играют исключительную роль в стимуляции роста и дифференцировки клеток (как у эмбриона, так и у взрослого человека), в развитии и функционировании костной и покровных тканей, а также обеспечивают нормальную работу зрительного анализатора: четкость, контрастность, цветовосприятие.
One of the most important functions of retinoids is a pronounced antioxidant activity. At the same time, activity in oxidation-reduction processes largely depends on the sufficiency in the body of zinc, iron and magnesium. Therefore, the food should be balanced absolutely for all substances.
If the retinoids are deficient, the activity of free radicals increases, the first visible result of which is the peeling and dryness of the skin. Later, this is accompanied by a decrease in vision in the evening and at night. At the same time, the development and differentiation of the tissues of a future child is slowed down, the normal functioning of the placenta is disrupted, which can lead to a delay in intrauterine development. In the most neglected cases left without correction by doctors, A-vitamin deficiency can lead to even an innate pathology - the cleavage of the upper palate of the fetus.
Unlike retinoids, carotenoids come into the body with plant food. The main food source of beta-carotene are carrots, pumpkin, apricots (and dried apricots), spinach. Other varieties of carotenoids are rich in tomatoes, broccoli, sweet peppers and zucchini.
Сочетание продуктов, содержащих carotenoids, с жирами значительно повышает их усвояемость. Вот почему рекомендуется есть морковь со сметаной, тыквенную кашу на молоке и со сливочным маслом, салат из томатов и перцев заправлять 10%-ной сметаной. Для повышения доступности каротиноидов необходимо присутствие пищевых жиров. Наиболее эффективно доступность витамина А повышается в присутствии молочных жиров, поэтому и рекомендуются сметанные заправки, а не заправки из растительных масел. Можно сказать, что carotenoids лучше усваиваются с расти-тельным маслом, чем без него, но лучше со сметаной, чем с растительным маслом. Дефицит каротиноидов в организме проявляется только с одновременным дефицитом ретиноидов, так как эти соединения могут взаимозамещать друг друга в условиях дефицита одного из них. Как только запасы обоих видов соединений истощены, появляются признаки их недостатка, известные под общим названием «признаки дефицита витамина А».
Vitamin E. The most popular and universal antioxidant for today, undoubtedly, is vitamin E, or tocopherol, the mechanism of its protective effect is as follows. Tocopherol is embedded in the cell membrane, thus preventing the attack of free radicals and the destruction of the cell. It also independently binds free radicals, stopping the chain reaction of oxidation.
In recent years, new data have appeared that, due to its antioxidant activity, vitamin E prevents premature aging, the development of atherosclerosis and tumor processes, and also normalizes respiration at the cellular level.
The main sources of tocopherol are vegetable oils and products containing them by nature (seeds, nuts, cereals) or by recipe (bakery products, pasta, mayonnaise). The most rich in vitamin E is rapeseed, cottonseed and soybean oil, as well as almonds (however, one should not abuse nuts because of their high allergenic potential).
Deficiency of vitamin E is extremely rare, due to its widespread distribution in food, but during pregnancy, when the total metabolism increases, there may be signs of relative E-vitamin deficiency. They include general weakness, decreased muscle strength, dry skin and some other nonspecific manifestations.
Vitamin C. By the number of simultaneously performed functions in the body, vitamin C is the undoubted leader. Firstly, considering its antioxidant qualities, it is worth noting that ascorbic acid fights free radicals and peroxides directly, providing reliable protection of proteins, fats, DNA and RNA (genetic material) cells. It protects against the oxidation of vital cellular enzymes, as well as restores the activity of vitamin E that has lost its activity. Secondly, vitamin C is responsible for the assimilation and exchange of most vitamins and minerals. Thirdly, it is involved in the synthesis of collagen fibers - the basis of connective tissue, norepinephrine (a stress hormone related to adrenaline) and serotonin (a biologically active substance that controls appetite, sleep, mood and emotions), bile acids and many hormones. In recent years, numerous confirmations of the participation of vitamin C in maintaining normal immunity have been received.
The main sources of vitamin C are herbal products. They are especially rich in wild rose, sweet pepper, sea-buckthorn, black currant, greens, potatoes and cabbage.
To increase the availability of vitamin C, you must remember the following features. The most saturated with ascorbic acid peripheral areas of plants (green leaves, peel of vegetables and fruits). However, even the highest concentration of vitamin C can be lost when cooking, due to its special instability. So, when cooking soup is lost up to 50%, and when fried - up to 90% of ascorbic acid. To prevent vitamin loss, there are some nuances that the expectant mother must take into account. To reduce the culinary loss will help to cook vegetables (such as potatoes) in the peel. In this case, vegetables should be added to already boiling water and cook in a saucepan closed with a lid.
With a deficiency of ascorbic acid, the walls of the vessels become thinner, bleeding gums appear, the fragility of the capillaries increases, which can lead to a small-scale rash on the surface of the skin. The skin itself becomes dry, on it appear "pimples", called "goosebumps". A similar condition of the vessels is also characteristic of the placenta, as a result of which the blood supply of the unborn child worsens.
Селен. It is the main microelement involved in the antioxidant defense of the body. As part of cellular enzymes, selenium provides for the destruction of free radicals in cells, protects the vessels from active oxidation with nitrogenous slags, and also ensures the activation of ascorbic acid and vitamin E. In addition, selenium participates in the regulation of thyroid hormones, has a detoxification effect on heavy metals entering in the body from the environment, prevents the development of tumors.
Food sources of selenium are very diverse. It enters the body with grains, nuts, meat and green onions. The greatest quantities of selenium are found in seafood, poultry meat, cheese and milk. In recent years, have learned how to grow selenium-enriched leeks and garlic.
Lack of selenium is relatively rare, mainly in people with diseases of the gastrointestinal tract, when the absorption of the village, as well as other components that a person receives with food, is disrupted. The manifestations of selenium deficiency include muscle weakness, weight loss, damage to the muscle tissue of the heart, soreness of the joints and decreased immunity.
Antioxidants in cosmetics
Studies have proven the high effectiveness of antioxidants in the fight against skin aging. In addition to the traditional vitamins A, E and C, the compounds that literally accomplished the revolution in cosmetology in the late XX - early XXI century are added to the creams:
Coenzyme Q-10, or ubiquinone, contained in natural vegetable oils and nuts, is a powerful antioxidant that prevents premature aging, increases skin elasticity and moisture content in cells. In addition, Q-10 promotes the recovery of tocopherol and increases the vital potential of cells.
Retinol, as the strongest antioxidant, prevents the exposure of the skin to ultraviolet rays, protecting it from the effect of photoaging.
Катехины (polyphenols) - antioxidants isolated from extracts of green tea. Catechins block the action of radicals, have anti-inflammatory and soothing effect on the skin, are used in anti-aging and sunscreen creams.
Antennian - substances isolated from grape seeds. They are able to block the action of enzymes that activate free radicals, and also to bind and remove toxins from the skin.
Moderation and accuracy!
Excessive levels of antioxidant substances in the body can be dangerous. This should be remembered for the future mother. Excessive desire to protect the future baby can lead to negative consequences:
The daily physiological norm of vitamin A is 0.8 mg. A significant drug excess of this dose can lead to a violation of embryo development, so the maximum intake of vitamin A should not be more than three daily rates.
The daily requirement for tocopherol varies from 8 to 12 mg. Hypervitaminosis of vitamin E is not accurately described, but there is evidence that with prolonged excessive intake of large amounts of tocopherol, immunity decreased and sluggish, antibiotic-resistant infectious processes developed. In addition, high doses of tocopherol reduce blood coagulability, which increases the risk of bleeding, including internal bleeding.
> Гипервитаминоз аскорбиновой кислоты не встречается: поступая в организм, она немедленно расходуется на различные нужды, а ее избыток выделяется почками. Суточная норма витамина С равна 50-70 мг. Однако превышение витамина С более чем в 10 раз, связанное с его дополнительным систематическим приемом, усиливает вероятность развития аллергических реакций. Кроме того, повышается проницаемость сосудов, ухудшается питание тканей, вследствие чего нарушается функция плаценты.
The norms and need for selenium are not exactly established. Safe intake is 50-200 mg / day, but this amount is strictly individual. With excessive enthusiasm for selenium supplements, a marked toxic effect can develop. Typical symptoms of selenium poisoning are increased hair loss and brittle nails, jaundice of the skin and its peeling, anemia, loss of appetite and decreased mood. With selenium it is necessary to be especially cautious to pregnant women, since the negative effect of its use for the unborn child can exceed the negative effect of the influence of free radicals: an excess of selenium can cause a pronounced teratogenic effect, that is, provoke the formation of malformations of the fetus, often incompatible with the child's life.
In order to avoid a lack of antioxidants, the first thing a young mother should do is to eat well and fully. Fresh fruits and vegetables, boiled meat, fish dishes, a sufficient number of dairy products - this is the basis of nutrition during pregnancy. Excessive intake of vitamins and trace elements and their subsequent negative effects when consuming food should not be feared, and in no case should you deliberately restrict yourself.
The need for a future mother in vitamin and mineral complexes can only be determined by the doctor who leads the pregnancy. He (and only he!) Has the right to prescribe antioxidant supplementation.