On July 11, 2021, Virgin Atlantic founder Branson entered space in his own space plane, becoming the first person in the world to travel commercially in space. A few days later, Amazon founder Bezos followed suit on his first commercial trip to space. Two months later, The spaceX of Musk, the world's richest man, also made its commercial debut.
The success of the first flight of these three private companies has made it possible for non-professional astronauts to enter space and open the first year of commercial travel in space. Scientists, however, warn that the human body has not yet evolved to the point where it can cope with the environment in space.
According to foreign media reports on the 17th, since human beings first opened up outer space life, researchers have noticed that astronauts have a "strange and continuous" red blood cell loss phenomenon. They call this phenomenon "space anemia," the cause of which has remained a mystery. Some experts believe that space anemia is only a short-term phenomenon, a temporary compensation for the body's fluid changes in microgravity.
Six-month follow-up studies of 14 astronauts on missions to the International Space Station showed that the rate of human red blood cell destruction was 54% higher in space. Image according to NASA
However, a new study published in the journal Nature Medicine points out that the space environment can cause the human blood to "self-destruct," a more destructive and persistent mechanism. To solve the puzzle, Canadian researchers followed 14 astronauts on missions on the International Space Station for 6 months, and to their astonishing results, astronauts destroyed 54 percent more red blood cells in six months in space. The results were not related to the gender of the astronauts.
These data were obtained through tests for iron levels in the blood and carbon monoxide respiration tests. Since human red blood cells produce carbon monoxide every time they are destroyed, astronauts are required to exhale regularly against jars and bring all of them back to Earth. Subsequently, the researchers tested this carbon monoxide and found that up to 3 million red blood cells were destroyed every second in the astronauts' bodies, 54% higher than the average rate when they were on Earth.
Even a year after returning to Earth, the rate of red blood cell destruction in astronauts is still 30 percent higher than before the spaceflight. Research has also shown that the longer a person stays in space, the longer they can anemia after returning to land.
This is reportedly the world's first scientific study on this issue. However, despite understanding the extent to which the space environment can damage blood, researchers are still not sure why this confusing phenomenon occurs.
In microgravity, blood accumulates in the head and chest, and about 10% of the fluid flowing through the blood vessels is lost. That's why astronauts sometimes look bloated in videos shot at the International Space Station. For years, scientists believed that this was the cause of "space anemia," the idea that the loss of red blood cells could be a way for the body to compensate for the loss of blood volume.
However, this latest study overturns this hypothesis, because the loss of red blood cells throughout the space flight did not keep the composition of human blood in balance, but continued to increase unabated. Even after 120 days, when all the red blood cells in the astronaut's body were produced in space, the loss of red blood cells continued at the same rate.
The space environment may cause human blood to "self-destruct."
In space, the loss of astronauts' red blood cells appears to cause iron serum circulation in their blood to be higher than normal. Without enough red blood cells to transport iron throughout the body, astronauts gradually began to develop mild and moderate hemolytic anemia.
The researchers suspect that bone marrow or spleen may be to blame and are ready to embark on further research. They also plan to conduct a longer-term experiment to see what happens to the blood after astronauts have been in space for a year.
They write in the paper that as humans plan to travel extraterrestrially, understanding the impact of space life on human health is critical to travel safety. Because red blood cells are so important for maintaining energy levels and healing wounds, these findings could also help space agencies decide how long to go on a space mission and how to treat wounds or diseases in space.
Red Star News reporter Xu Huan
Edited by Guo Yu
(Download Red Star News, there are prizes for the newspaper!) ）