Why astronauts get space anemia – New research shows

Travel to space destroy many more red blood cells or red blood cells than on Earth, causing prolonged space anemia which may prove to be a serious problem in future manned space missions. This emerges from a new Canadian scientific research, the first of its kind in the world, which took place in the body 14 astronauts and showed that they had lost 54% more red blood cells than their normal expected cell losses if they had not traveled in space.

The researchers, led by Professor Guy Trindell of the University of Canada and the University of Ottawa, who published the paper in the journal Nature Medicine, said that space anemia was systematically detected when astronauts returned to Earth. their first space missions, but until today we did not know why it happened. Our study shows that once astronauts reach space, more of their red blood cells are destroyed and this continues throughout their mission. “

Prior to this study, according to the Athenian-Macedonian News Agency, it was believed that space anemia it was simply a rapid adaptation to the displacement of fluids in the upper part of the astronauts’ bodies when they reached space. Astronauts thus lose 10% of the fluid in their blood vessels. The scientists thought that a corresponding 10% of their red blood cells (hemolysis) were rapidly destroyed in the astronauts’ bodies in order to restore fluid balance, which is estimated to happen after 10-15 days.

But the new research, funded by the Canadian Space Agency, found that the destruction of erythrocytes – which carry oxygen from the lungs throughout the body thus playing a vital role – is not caused by fluid imbalance in the body, but is a primary consequence of the very fact that the body is suddenly in space. This was confirmed because the destruction of red blood cells in 14 astronauts was monitored and measured during their entire six-month stay on the International Space Station.

On Earth, the human body creates and destroys nearly two million red blood cells every second, but over time the rate of destruction increases to about three million per second (an increase of 54%). The same is true of both male and female astronauts, who feel equally weak and tired due to space anemia.

“Fortunately, having fewer red blood cells in space is not a problem when the body is experiencing a lack of gravity. But when it returns to Earth or in the future is likely to land on other planets or satellites, anemia will affect the energy, endurance and strength of the astronauts, which could jeopardize the goals of a mission. “The effects of anemia are only felt when one lands and has to deal with gravity again,” said Dr Trindel. As he said, space anemia is reminiscent of the condition of patients who have been in the ICU for a long time due to Covid-19 or another disease.

The MARROW study of 14 astronauts showed that space anemia is reversible, but on Earth it takes three to four months for red blood cells to gradually return to normal levels. But again, one year after returning to Earth (a worryingly long time for an astronaut on another planet), the destruction of astronaut red cells remained 30% above levels before they went into space. It has been found that the longer the stay in space, the worse the space anemia, which concerns in particular future missions to the Moon and, even more so to Mars, a return journey that will take at least two years.

The impact of the new findings also affects future space tourists, especially if they suffer from anemia or other blood disorders. Both they and the astronauts will need a special diet, with more iron and more calories, to increase their red blood cell production both during and after space travel. On the other hand, according to scientists, it remains unknown for how long the body can undergo this faster destruction and production of blood cells in the blood, in order to self-repair.