antioxidants: how their sources work, the effect of antioxidants on the body
The main role of the antioxidant system is to protect against free radicals. To do this, the body uses antioxidants. which are synthesized independently and obtained from food. That is why the lack of antioxidants can be dangerous to health. follow this article to know Antioxidants: how their sources work, the effect of antioxidants on the body
Antioxidants: what are they
Antioxidants are chemical compounds of various classes that can protect the body from free radicals. Considering how closely these two ideas are connected. Let's start by defining free radicals.
Free radicals are a by-product of metabolism or a consequence of exposure of tissues to solar or ionizing radiation, and tobacco smoke. These are chemically unstable compounds that have lost an electron and seek to remove the missing electron from the surrounding molecules to restore the electron pair.
Free radicals are dangerous for the body:
when interacting with them, molecules lose an external electronic shell, which changes their properties. As a result, substances lose their normal functions and turn into free radicals,
which causes damage to other molecules:
breaks occur in DNA. low-density lipoproteins become more susceptible to the formation of atherosclerotic plaques in blood vessels. the ability of cell membranes to regulate the flow of substances is disrupted. Free radical-induced oxidative stress and cancer have been connected. cataracts, atherosclerosis, diabetes, Alzheimer's disease. and the aging process.
How are antioxidants classified?
There are natural antioxidants made by living organisms,. and synthetic ones. substances created in the laboratory. such as allopurinol.
Part of the natural antioxidants to protect against oxidative stress - enzymes or complex molecules
the body makes on its own, among them:
- Enzyme Q10 (ubiquinone).
- Alpha lipoic acid
- Glutathione.
Some antioxidants are ingested through food.
Some micronutrients, plant-derived chemicals, and many vitamins have antioxidant properties:
- Vitamin C
- Vitamin E
- Beta-carotene
- Selenium
- Manganese.
- Flavonoids.
- Phenols and polyphenols.
According to the type of action, primary antioxidants are distinguished, which directly neutralize free radicals and secondary ones that prevent their occurrence.
The main antioxidant gives the free radical an electron. which leads to its inactivation, but after that, the antioxidant molecule does not become radical and does not acquire the ability to take electrons - chain reactions with the loss of electrons by molecules and the loss of their proper structure stop.
Secondary antioxidants protect the body from oxidative stress by affecting metabolic processes: they reduce the activity of oxidase enzymes that produce free radicals. inhibit inflammation, and affect the synthesis of enzymes.
Sources of antioxidants
Antioxidants, which the body must receive from food, are present in sufficient quantities in the diet of a resident of developed countries. The recommendation is to take vitamins and dietary supplements. for the Prevention of antioxidant deficiency is unfounded since good nutrition allows you to get all the substances. that the body needs to avoid developing a deficiency in healthy people.
Vitamin C is found in large quantities in broccoli, oranges, lemons, Kiwi, tomatoes, and sweet peppers.
Vitamin E in greens, avocados, spinach, and sunflower seeds.
Carotenoids in carrots, broccoli, and mangoes. peaches, tomatoes, and pumpkins.
Selenium and zinc are obtained from fish and beef. brown rice, shellfish, and nuts.
Antioxidant phenolic compounds can be found in apples, berries, grapes, tea, and cocoa.
Of course, some foods contain more antioxidants than others.
The database of foods and their antioxidant properties published on the USDA website, which was later removed due to the changed understanding of antioxidant functions, even caused the term superfood or superfood to appear, which marketers immediately began to use, and. as statistics show. very successful: 80% of respondents consider that such products as medicines - sales are growing. In 2015 alone, there was a 36% increase in the frequency of labeling food as superfoods and superfoods on the world market. Blueberries, broccoli, green tea, avocado. salmon - the list of foods with this label is growing. The attention of buyers is attracted by the promise of high content of the best natural antioxidants.
Meanwhile
experts believe that building a diet around a small selection of advertised products is not useful (you can always find the same nutritional value. but not as fashionable substitutes on store shelves). and dangerous: one of the criteria of a healthy diet is dietary diversity. its restriction can lead to a lack of vitamins and minerals.
The effect of antioxidants on the body: is there a benefit from taking them
Most of the promises made by manufacturers of dietary supplements, cosmetics, and food with a high content of antioxidants have no scientific basis - this is the opinion of the World Health Organization today.
Of all the proposed effects, the ability of vitamin C in large doses to lower blood pressure and cholesterol levels. as well as in alleviating the course of colds, but not their Prevention, has been proven. Taking antioxidants in normal daily doses, which are usually presented in dietary supplements. and vitamin complexes, cannot reduce the likelihood of developing cardiovascular. and Infectious Diseases.
There is not enough evidence to support the ability of antioxidant supplements to reduce the likelihood of developing diabetes, and cataracts, too. and neurological degenerative conditions. Dietary supplements are not able to prevent the development of cancer.
for the antioxidant effect of food
in reducing the likelihood of cancer and metabolic diseases, it is impossible to say whether the positive effect of eating vegetables and fruits is caused by antioxidants since vegetables and fruits contain vitamins in addition. And the minerals necessary for the body, fiber. and slow carbohydrates contribute to normal digestion and provide a gradual increase in glucose in the body.
But on the other hand
Who said that free radicals are necessarily bad Free radicals are not always a dangerous by-product of metabolism-many processes in the body cannot do without them: immune cells use free radicals to neutralize bacteria. viruses, and cancer cells. Does this mean that too active consumption of synthetic antioxidants will lead to a violation of these functions?
As it turned out
yes: long-term studies have shown that taking beta-carotene, vitamin A and vitamin E increases the likelihood of lung cancer and mortality in smokers and those who have worked with asbestos. Women supplemented with vitamins C, and E, beta-carotene, selenium, and zinc were more likely to develop skin cancer. and men taking vitamin E increased the risk of prostate cancer. To date, the dangers of antioxidant dietary supplements are still one of the few fully proven effects.
Antioxidant dietary supplements interact with medications:
vitamin E enhances the effect of blood thinners. the probability of bleeding rises. and antioxidants can reduce the effectiveness of anticancer therapy - therefore, during drug therapy. it is necessary to consult with your doctor before taking any medications and dietary supplements.
In addition, under certain conditions, antioxidants can also act as oxidizing agents:
they can take electrons from other molecules. causing them to become free radicals
Physiological processes in the body are interrelated. and interfering in this fragile system without indications is dangerous:
there is no conclusive evidence of the benefits of antioxidants. but there is convincing evidence of the dangers of taking dietary supplements containing them. A healthy diet provides the body. with all the necessary trace elements. vitamins, and antioxidants without health risks.