A study has revealed how space travel cause lower red blood cell counts. This is known as space anemia. Scientists have analysed 14 astronauts and showed us that their bodies destroyed 54 percent more red blood cells in space. This study has been published in Nature Medicine.
Scientists previously thought space anemia is a quick adaptation to fluids shifting into the astronaut’s upper body when they are in space. In this way astronauts lose 10 percent of the liquid in their blood vessels. Scientists thought astronauts destroy 10 percent of their red blood cells to keep balance. Red blood cell control is back to normal after 10 days in space.
But now scientists found that red blood cell destruction is a primary effect of being in space. This is not just caused by fluid shifts. Scientists measured the red blood cell destruction in 14 astronauts while they were in a six-month space mission.
Our bodies create and destroy 2 million red blood cells every second, on Earth. Scientists found the astronauts were destroying 54 percent more red blood cells while they were in space. This was same in both male and female astronauts. Scientists have used techniques and methods which they have developed to measure red blood cell destruction.
They have collected samples aboard the International Space Station by those methods. They have measured the tiny amounts of carbon monoxide in the breath samples. Every time one molecule of the deep-red pigment in red blood cells is destroyed, one molecule of carbon monoxide is produced.
Scientists did not measure red blood cell production directly. They thought that astronomers might produce extra red blood cells to compensate for the destroyed cells. Otherwise, they will suffer from severe anemia.
5 out of 13 astronauts were clinically anemic when they came back to Earth. 1 astronaut did not have blood drawn on landing. Scientists found that space-related anemia was reversible. Red blood cells levels progressively return to normal three to four months after their landing.
The scientists have experimented with the same astronauts one year after their returning. They found that red blood cell destruction was 30 percent above preflight levels. This suggest that structural changes have happened while the astronauts were in space. This have changed red blood cell control for up to a year.
This finding has many implications. It will support screening astronauts for existing blood conditions that are affected by anemia. Scientists have also found that the longer the space mission, the worse the anemia. This will impact long missions to the Moon and Mars. Increased red blood cell production is going to need an adapted diet for astronauts.
Scientists did not find how long the body can maintain this higher rate of destruction and production of red blood cells. This finding will also be useful for the people of Earth as well. Most patients become anemic after being very ill for a long time with limited mobility. Anemia prevents their ability to exercise and recover. Bedrest is a cause for anemia. But scientists do not know how this happens. Now scientists think that it is the same as space anemia. Scientists is going to test this hypothesis in their future research.