(August 22, 2015) Scientists
at MIPT have revealed that weak doses of gamma radiation prolong the life of
drosophila flies (fruit flies), and that the effect is stronger in females than
in males. These findings could reveal the genes that enable the prolongation of
life and in the future lead to the creation of a means to prevent aging in
humans. The results of their study can be found in an article recently
published in the prestigious scientific journal PLOS ONE
A group of scientists from the Laboratory of the Genetics of
Aging and Longevity at MIPT, the Engelhardt Institute of Molecular Biology at
the Russian Academy of Sciences, the Komi Research Center and Syktyvkar
University under the leadership of Alexey Moskalev is studying the mechanism of
radiation hormesis, the effect by which moderate stress has a stimulating
effect on an organism and enables the prolongation of life. This effect was
first observed at the end of the XIX century by the German pharmacologist Hugo
Shulz who discovered that small doses of poison speed up the growth of yeast
cells. The effect was later found in many other organisms, in particular in peppermint
and roundworms.
“Small doses of poison or the moderate influence of other
stress factors affect the organism in such a way that the stimulation effect
overcomes the harm. As a consequence, this can lead to an increase in life
expectancy,” explains Svetlana Zhikrivetskaya, lead author of the article.
In recent years scientists have been actively studying the
influence of radiation hormesis, observing beneficial effects of weak doses of
ionizing radiation. It is a commonly accepted view that there can be no safe
doses of radiation, as any radiation will damage the molecules of DNA. An
acceptable background is considered to be that at which the risk of cancer is
negligibly small.
However, a number of experiments have demonstrated an
improvement “under radiation” of indicators of life expectancy in mice and cell
cultures. Indirect confirmation of radiation hormesis can be seen in cases of
accidental irradiation of large groups of people over extended periods of time.
In particular, in 1982 in Taiwan, during smelting, 20 tonnes
of steel were accidentally contaminated with cobalt-60. This steel was then
used as construction material and, for about 20 years, about 10 thousand people
were subjected to the effects of irradiation at a level of approximately one
thousand times that of the natural background. Scientists who have investigated
these people have drawn the conclusion that the number of cases of cancer in
this group of unwilling experimental subjects is lower than normal. This
conclusion has, however, been criticized and the very idea of radiation
hormesis has remained debatable.