Long stay in space reduces the effectiveness of immune cells in the fight against cancer

Cosmos is a dangerous place. Earlier studies have shown that a long stay in microgravity leads to loss of muscle mass and a decrease in bone density, can have negative effects on the work of the gastrointestinal tract, and can also affect the psyche. National and private space agencies around the world are working to send a man to Mars one day. However, the flight to the Red Planet will, apparently, still be that little ride. At least for the first people who go there. In the course of a new study, scientists from the University of Arizona discovered at least one more negative effect of a long stay in space. This can lead to cancer.

Experts have studied eight blood samplesastronauts who spent on board the International Space Station from 6 months or more and compared them with control blood samples taken from people who never flew to space. It turned out that long space travel reduces the effectiveness of the immune system in the fight against leukemia.

In the course financed by aerospaceNASA research, the results of which were recently published in the Journal of Applied Physiology, found that the effectiveness of NK cells, or so-called natural killer cells, possessing cytotoxicity against tumor cells and cells infected with viruses, differed significantly among astronauts. After 90 days spent in space, astronauts observed a 50 percent decrease in the effectiveness of this type of cell in the fight against leukemia.

Despite the fact that scientists have previously carried outthe connection between long space flights and an increased risk of cancer, the new study was able to demonstrate this for the first time by comparing the effectiveness of NK-cells of astronauts during, and not after, space flight.

"NASA and other space agencies are concernedwhether a person’s immune system will be at increased risk during long space missions. Our study shows that the risk of developing cancer during very long space flights is indeed higher because the body has an increased and more prolonged effect of radiation, ”says the head of research professor of trophology at the University of Arizona Richard Simpson.

Experts point out that their next taskis the study of the probability of a direct relationship between the decline in the functions of NK-cells and the individual susceptibility of astronauts to an increased risk of developing cancer. In addition, scientists are going to investigate in more detail other factors that may also affect the increase in this risk, such as excessive stress, microgravity conditions and radiation, as well as the relationship between the complex effects of all these factors on the body and the risk of developing cancer.

In the course of earlier research has already beenIt has been established that physical activity and a specialized diet can improve the efficiency of the functions of the immune system, at least in terrestrial conditions. Simpson and colleagues hope that a similar approach will help achieve the same positive results in microgravity conditions.

Understanding what exactly leads to a decreaseThe effectiveness of the immune system during long space flights is a crucial step towards our ability to conquer deep space, the researchers conclude.

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