24 August 2009

Antioxidants: for cancer or for cancer?

Vegetables and fruits help cancer cellsAlexey Tymoshenko, GZT.RU
American scientists have found out that antioxidants can promote the spread of tumor cells.

Previously, it was believed that these substances reduce the risk of ordinary cells turning into cancer cells. Most antioxidants are found in vegetables and fruits.Scientists emphasize that their work does not negate the existing medical view of antioxidants as substances that can reduce the risk of cell-threatening defects.

The point is that if a tumor has formed, cancer cells are more likely to reach other organs with an excess of antioxidants. Antioxidants from everything?

There are many myths around antioxidants.
Manufacturers of biologically active additives (dietary supplements) claim that "additional intake of antioxidants in the form of biologically active additives should become the norm of life for any person." Such an offer can be found, for example, on the website of one of the companies distributing dietary supplements. Nevertheless, this statement is hardly true. The Law of the Russian Federation

"Advertising of biologically active additives and food additives should not create the impression that they are medicinal products and (or) have medicinal properties" – this is an excerpt from the federal law "On Advertising" (Article 25).
In other words, it is impossible to cure with the help of dietary supplements simply by definition.The fact is that a certain number of free radicals are constantly formed in the body.

A free radical is, roughly speaking, a fragment of a molecule with high chemical activity. Hydrogen peroxide, for example, forms a lot of free radicals, and their activity eventually leads to the death of a number of microorganisms – this property of peroxide is used to disinfect abrasions.

Free radicals can also damage healthy cells, even causing mutations in their DNA. Extremely rarely, such mutations remain uncorrected by natural defense systems and even less often turn out to be dangerous for the body as a whole, turning a healthy cell into a cancerous one.

Antioxidants against cancer?The mechanism of cell damage prompted doctors (long before the work of American scientists) to assume that if the body receives more antioxidants, then the likelihood of getting cancer will decrease.

To test this hypothesis, many studies have been conducted.

The results turned out to be very far from the rosy promises of manufacturers of dietary supplements with antioxidants. In the work that the British Dietetic Foundation conducted in 2003, it is said that the only scientifically sound and practice-confirmed recommendation remains the advice to eat more vegetables and fruits. But the effect of pills with antioxidants could not be obtained.

Later, during a large-scale study involving 13 thousand people, French doctors from more than ten different scientific centers managed to identify the effect of dietary supplements containing antioxidants and confirm that the probability of getting cancer is reduced by 30%, but only in men. Scientists explained this unexpected effect initially with a lower level of natural antioxidants in the male body.

Antioxidants in cancerBut when a tumor has already appeared, antioxidants play a different role.
As American biologists from Harvard Medical Center and three other research and medical organizations have managed to establish, antioxidants prevent not only damage to healthy cells – they prevent the death of cells that have broken away from a cancerous tumor, which does not lead to anything good. As laboratory experiments have shown, normally cancer cells often die when separated from the tumor. The loss of communication with neighbors leads to a shortage of energy, and then to an attempt to restore the energy balance – more often unsuccessful and eventually turns into self-destruction.

But the addition of antioxidants allows tumor cells to recover from the loss of neighbors and gain independence. After that, such a cell risks getting into other organs with the blood or lymph flow and starting to divide uncontrollably in a new place, forming metastases.

It should be noted:So far, no human studies have been conducted.
Exactly how diet or taking antioxidants affect the risk of metastasis formation in patients can be confirmed after a large (several thousand participants) study. However, if the harmful effect has already been shown in the laboratory, this is a serious reason for reinsurance, especially if the positive aspects of taking antioxidants remain in question.

Not all diets are equally beneficial

The study once again confirmed that the body and its functioning are too complex to obey simple rules like "the more useful ingredient, the better." Even eating fruits and vegetables, which is recognized by nutritionists as healthy, while ignoring meat is not so unambiguously useful. Recent work by doctors from the UK and New Zealand, for example, has shown that vegetarians are less likely to get stomach cancer, but cervical cancer is more common in them than in those who eat with vegetables and meat.

Portal "Eternal youth" http://vechnayamolodost.ru24.08.2009

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