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Demographers study clearly show that the human lifespan depends primarily on social factors - quality of life and the state of medicine in the country where he lives.
In Japan, for example, life expectancy in the last 20 years has grown to 82.15, and in the kingdom of Swaziland also increased - to 32.3. Therefore calculate biologicheskiĭ "lifetime" of a person is difficult, especially since most of the elderly dying of lyudeĭ bolezneĭ, not of old age. Most, but not all.
In the XIX century, scientists discovered the law, carries the names kotoryĭ Gompertz and Meĭkhema and describes the dependence of mortality on age. Initially with increasing age mortality increases exponentially. It seems obvious that the 70-year-old died more than 60 years, and 80-year-olds - more than 70 years. But in opisyvayuscheĭ law krivoĭ is one mystery - after the turn of the 90 years it goes to the so-called plateau. This means that if a man has stepped over that age, the probability of death - 90, 100 years or more to him about the same. This phenomenon dolgozhiteleĭ scientists can not explain.
Likely to plateau out the lucky ones who managed to avoid senile bolezneĭ. and it can be assumed and that the aging process in old age, as it were stopped. However, aging gives researchers more mysteries than longevity. This is evident in the very first number theory aging.
SO, aging - it's ...
1. Program: "Better to die than to make a mistake"
This postulate is the basis of the theory of one of the main experts on aging in Russia Vladimir Skulachev. He introduced the concept of "phenoptosis" - the programmed death of an organism, similar to apoptosis, programmed cell death. It would seem, why a program to death? Then, it is beneficial populations and species. In the words of Skulachev, nature has a "Samurai law of biology", which states that "it is better to die than to make a mistake." This means that the body, which is no longer needed, but a hundred times-renie - a program that believes Vladimir Skulachev, means "you can cancel it." In support of his theory, he gives examples of non-aging organisms in nature, in which the death occurs without aging.
Other scientists - the adherents of evolutionary theories of aging emphasize that the body makes a choice between repair and reproduction. Repair of cells and tissues requires a lot of energy - cheaper, faster multiply.
2. Damage accumulation: with age, the body begins to work less
Because with age, the body begins to work less, then it's some spoils. The question is what it is. Some experts believe the most important thing that the port proteins. For example, in the molecules of collagen, which is about one third of the structural proteins in the body, between the long helical filaments crosslinking "bridges" that are stitched together the threads, resulting in tissue loses its elasticity.
At the level of the cell deteriorate mitochondria - cellular power substation. This can lead to the fact that the cell gets in the way of programmed death.
3. Spoilage genes body accumulates harmful mutations
Finally, in old age appear genetic damage. After the body has ceased to multiply, it accumulates harmful mutations. There is no transfer of risk to their offspring, then, can be "spoiled" as they want. Harmful mutations can lead
and impairment of protein synthesis, and to cancer, for example. To genetic factors, aging and many are still mysterious mobile elements - short sequences that move along the DNA molecule and affect genes. With age, they become more. And there are mutations that directly cause premature aging - progeria or, conversely, "forever young."
4. Razregulyatsiya: breaking mechanism of gene regulation
About ten years ago, American scientists have found out why the yeast aging - they break the mechanism of gene regulation. The new study showed that in mammals are all exactly the same. This is a universal cause, scientists say. Hence, the causes of aging can not be genetic and epigenetic, that is lying next to the genes.
5. Blight "packaging" of DNA sections: Getting Started unnecessary and harmful genes
In the cell nucleus the DNA molecule is wound on histone proteins. These proteins can be modified, which determines the density of packing. With age, the chromatin in the nucleus becomes more loose, and it leads to what is beginning to work unnecessary and harmful genes. The packing is dense - genes do not work, wrap loose - genes work.
In general, the body is too complex, consists of a large number of elements, and when some of the elements fails, the system crashes. There are even attempts to mathematically explain aging to the theory of fractals, this theory develops Russian researcher Alexey Moskalev.
This is only the basic theory. So scientists wishing to find the "elixir of immortality", increase life expectancy, or at least to slow aging is, where to roam. The main thing - to find the target, which can be affected. On this task beating gerontologists around the world, practicing approaches in laboratory animals: nematode worms, fruit flies, mice. Some things work.
So, to defeat aging, you can ...
1. Manipulate genes
Schmukler Robert Rees, professor at the University of Arkansas, switched off in the genome of the nematode C.elegans one gene - Age-1. And in this way he was able to increase the life of the worm in 10 times! Nematode rather simple organism, and expect such impressive results on other sites do not have. Russian researcher Alexey Moskalev way extended the life of the fly Drosophila by only 10%.
2. Build on telomeres
Overcome aging organs and tissues of mice by an add telomeres in stem cells have scientists from Harvard Medical School. True, they did not work with normal mice, and the mutants that are rapidly getting old. The enzyme telomerase, which builds telomeres to normal length, these mice did not work even in stem cells, where it should provide long division. And of mice themselves into quite a young age appeared signs of aging: degraded testes, spleen, brain, broken nose.
Degeneration was reversed when scientists biochemically restored telomerase activity in the cells. This led to a lengthening of telomeres and the resumption of cell division. In mice that have been restored in testis, spleen, and brain, and they again began to smell.
3. Arrange attack antioxidants
Antioxidants - these nutrients - found in green tea, grape seed, red wine and other products. But scientists, including Vladimir Skulachev, argue that the natural antioxidants is low, because this is not the most "hot spots" are not in the mitochondria. Skulachev invented their antioxidants, which in his honor called "Skulachev ions". This positively charged ions, the properties of which allow them to penetrate into the mitochondria. there is something they neutralize reactive oxygen species.
Skulachev ions are tested on animals. True, drastically extend the life of experimental mice is not possible - only 30%, but managed to push their old age. "Animals are active until shortly before his death, showing the typical signs of aging, - said Vladimir Skulachev. - We were able to struggle with aging, but not with mortality in very old age. "
4. Restrict caloric intake
This is a very popular way that many times been tested on animals. Reduction of rats and mice consumed calories by 30% on average 30% increase life expectancy.
Trying to explain this phenomenon, the researchers first decided that calorie restriction slows the aerobic respiration, which is a source of reactive oxygen species. But it turned out that the breath while limiting calories increases, and thus, increases the level of reactive oxygen species. Another hypothesis equates to a moderate calorie restriction oxidative stress, which, as it fits the body for subsequent high oxidative stress. That is, when the age of reactive oxygen species is much trained in small doses, the body easier to cope with them.
However, another study in mice showed that fasting does not prolong the life of all animals, but only in mice that were genetically prone to obesity and body which the observed energy imbalance. Scientists believe that it can be fully attributed to the people. They warn people with normal physique on to diet and otherwise limit myself, they do not need. But the fat man's dietary restriction will benefit.
5. Increase physical activity.
The experimental mice were forced to run on the treadmill and in the wheel longer retain youth and health than their sedentary counterparts. Scientists believe that physical activity increases the number and quality of mitochondria. Researchers at McMaster University (Canada), for example, worked with mice prone to premature aging due to high levels of mutations in mitochondrial DNA. One group of mice lived in normal conditions, and the other three times a week to play sports. Three months later, it was found that the mouse-athletes to preserve youth and health, comparable to that of wild animals. Their mitochondria remain functional full. The fate of the control group was sad.
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