A long stay in space reduces the efficiency of immune cells in cancer

Space is a dangerous place. Earlier studies have shown that a long stay in microgravity leads to loss of muscle mass and decrease in bone density can have negative effects on the gastrointestinal tract, and can affect the psyche. National and private space agencies around the world are working to one day send man to Mars. However, the flight to the red planet will be, apparently, quite a ride. At least for the first people who go there. In the new study, researchers from Arizona state University found at least one negative effect of a long stay in space. This can lead to the development of cancer.

Experts have studied eight blood samples of astronauts who spent aboard the International space station from 6 or more months and compared them with control samples of blood taken from people who are in space never flew. It turned out that for a long space travel to reduce the effectiveness of the immune system in the fight against leukemia.

In the course of funded aerospace Agency NASA study, whose results were recently published in the Journal of Applied Physiology, it was found that the effectiveness of NK cells or so-called natural killer cells with cytotoxicity against tumor cells and cells infected by viruses differed significantly among the astronauts. After 90 days in space, the astronauts had observed a 50 percent reduction of the effectiveness of this type of cells in leukaemia.

Despite the fact that scientists have had the connection between long-duration space flight and an increased risk of developing cancer, a new study has for the first time able to demonstrate this by comparing the effectiveness of NK-cells of astronauts during and not after space flight.

“NASA and other space Agency is concerned whether the human immune system be at greater risk during long space missions. Our study shows that the risk of developing cancer during a very long space flights is higher because the body is increased and more prolonged exposure to radiation,” — says the head of research Professor of trophology at the Arizona state University Richard Simpson.

Experts note that their next task is to study the probability of a direct link between the decrease in the function of NK cells and susceptibility of individual astronauts to increased risk of developing cancer. In addition, scientists are going further explore other factors that can also contribute to this risk, such as excessive stress, microgravity and radiation, as well as the relationship between the complex influence of all these factors on the organism and the risk of developing cancer.

During earlier research it was already established that physical activity and a specialized diet can improve the effectiveness of the immune system at least in earthly terms. Simpson with colleagues hope that a similar approach will allow to achieve the same positive results and in microgravity.

The understanding of what leads to the reduced efficiency of the immune system during prolonged space flight is a critical step forward in our ability to conquer the far reaches of space, summarize the researchers.