- Antioxidants: the truth about the notorious benefits
- Mechanism of action
Trillion cells that comprise a human body during the life faces a multitude of dangers from a lack of nutrients to viral and other infections. One of the constant threats to the cells of the body are chemicals known as free radicals. They can damage the cells and genetic material. The body itself generates free radicals - they are the inevitable by-product of processing food into energy. Free radicals are also found in foods that people eat and in the air he breathes. Some of them are formed under the action of sunlight on the skin and eyes.
Free radicals are omnipresent, but we have effective protection against them - antioxidants. At the free radicals, whatever they may be different in shape, size and chemical composition, have one thing in common - they rob electrons from any substances which appear next to them and thereby destroy any tissue. They can even change the instructions encoded in the DNA. Antioxidants generously share electrons to free radicals.
There are hundreds, perhaps thousands of substances that act as antioxidants. Virtually every known antioxidants such as vitamin C, vitamin E, beta-carotene, selenium, manganese. In addition, they include glutathione, coenzyme Q10, lipoic acid, flavonoids, phenols, polyphenols, phytoestrogens.
The use of the term "antioxidant" to substances may be misleading. Means a chemical antioxidant properties, in particular, the ability of a substance to act as an electron donor. Some antioxidants to a certain chemical environment can act as pro-oxidants - that is the substance that fills up electrons from molecules.
Another common misconception with regard to antioxidants is believed that they are interchangeable. This is not true. Each of them has its own unique chemical and biological properties.
It is believed that antioxidants evolved as part of a complex system in which each substance or group of substances playing specific roles. This means that no one antioxidant will do the work for the rest - that is, other antioxidants.
Antioxidants and Health
The focus of public attention antioxidants were in the 1990s, when scientists began to realize that free radicals contribute to the development of diseases such as atherosclerosis, cancer, vision loss, and many other chronic disorders. Some studies have shown that people who ate little of foods rich in antioxidants (especially fruits and vegetables), often ill various chronic diseases than those who ate fruits and vegetables in sufficient quantities. In clinical trials tested the effect of individual antioxidants, especially beta-carotene and vitamin E, to the development of cardiovascular disease and cancer.
Even before the final results were known studies of media in different ways began to extol the beneficial properties of antioxidants. Frozen berries, green tea, and many other products have received the title of richest sources of antioxidants, and their sales have increased rapidly. Coming soon appeared supplements containing antioxidants - their manufacturers enthusiastically talked about how these wonderful tools to help prevent many serious diseases and ensure a long healthy life.
Research results were mixed, but most of them did not find the expected beneficial properties of antioxidants. Most reports on the results of the study suggest that vitamin E and other antioxidants are not able to protect against heart disease, cancer and other diseases. According to one study, beta-carotene even increases the likelihood of developing lung cancer in smokers.
Some researchers have found benefits of antioxidants. For example, it was found the ability of beta-carotene reduces the risk of mental activity in the elderly.
These mostly are not very optimistic results have not prevented many producers and traders earn on antioxidants.
- Heart disease and antioxidants
Vitamin E, beta-carotene and other antioxidants are not silver bullet against heart disease.
In one study of women's health attended by 39 876 initially healthy women; for ten years after the day they took 600 IU of vitamin E or a placebo. In ten years the number of women with heart disease (and cancer) among those who took vitamin E, there were lower than those taking placebo. However, in the first group of mortality from cardiovascular disease was 24% lower than in the second group - among women taking placebo.
Other studies, however, showed no benefit of vitamin E. For example, in one study, the number of cases of serious cardiovascular diseases including taking vitamin E and placebo
Placebo - an effective tool for self-hypnosis
It was almost the same - 21.5% and 20.6%, respectively. The first group was a marked increased risk of heart failure hospitalization and result in heart failure.
The role of antioxidants in cancer prevention is also not entirely clear. In one study found no difference in the incidence of cancer in men taking beta-carotene or placebo. According to the results of another study, antioxidants may reduce the risk of cancer in men, however, have taken part in the study, women were observed similar results.
Participants in another study, long-term taking selenium significantly decreased risk of death from a variety of cancers, including colon cancer
Colon cancer: creeps imperceptibly
, Lung and prostate. The effect was especially pronounced in subjects who initially have low selenium levels in the body.
- Age-related eye diseases and antioxidants
In this area is more or less bright spot information field relating to antioxidants. In the course lasted for six years, the study found that the combination of vitamins C and E, beta carotene and zinc provides a degree of protection against the development of macular degeneration, but not cataract
Cataracts - how to solve the problem completely?
In people at risk for the disease. Lutein, an antioxidant contained in green, for example, spinach, may also help to preserve vision. However, reliable information about the effects of this antioxidant is too small.
The potential danger of antioxidants
If antioxidants are harmless, there would be nothing wrong with that many people take them just in case. However, some scientific evidence suggests that antioxidants may be hazardous to health.
In Finland, a large-scale study of the effect of beta-carotene in the group of active smokers - and therefore, people with an increased risk of developing lung cancer. The tests were stopped early when researchers noticed a significant increase in the incidence of lung cancer among those who took beta-carotene compared to the group receiving placebo.
In another study, smokers and people who are regularly exposed to asbestos took beta-carotene and vitamin A. And again, those taking anti-oxidants, it was noted an increase in the incidence of lung cancer compared with those who took a placebo. However, another study, which lasted 18 years, showed no such action of beta-carotene (however, it was attended not so much active smokers).
Another alarming sign: among female subjects who were taking the same antioxidants, like vitamins C and E, beta-carotene, selenium and zinc, there were more cases of skin cancer than among placebo.
Free radicals contribute to the development of many chronic diseases, including - cancer, heart disease, vision loss, Alzheimer's disease. This does not mean that a substance having antioxidant properties can cope with the problem. The research results are contradictory and do not allow to draw definitive conclusions, but it is quite obvious that the antioxidants are not a magic bullet against disease. At the same time for professionals no doubt that the fruits and vegetables that contain, besides other mineral substances and antioxidants have a beneficial effect on health. You can most likely assume that eating natural sources of antioxidants, without overuse of food additives containing them
Food additives - basic classification
Maybe not much use, but not hurt.