Scientists have learned more about how space travel increases anemia in astronauts after they return to Earth.
Canadian researchers say that 50% more red blood cells are destroyed in space, and that this continues no matter how long the mission takes.
As a result, long trips to the Moon, Mars and beyond may present a challenge, according to the researchers.
But their findings could benefit patients who are bedridden on the floor with the same condition.
Scientists have been aware of “space anemia” since the first missions returned to Earth, but exactly why it occurred has remained a mystery.
Now, more has been learned, thanks to a small study at the University of Ottawa of 14 astronauts, who each spent six months on the International Space Station.
Using blood and breath samples taken during their expeditions, the researchers were able to measure the amount of red blood cell loss. These cells are the key to life, carrying oxygen from the lungs to all parts of the body.
“Our study shows that upon reaching space, more red blood cells are destroyed, and that this continues for the duration of an astronaut’s mission,” said lead author Dr. Guy Trudel.
And it’s not a problem while in space, because of the weightlessness, but on Earth, it means that astronauts lose bone density and muscle strength, and they feel very tired.
Three million red blood cells are destroyed per second in space, compared to two million red blood cells on Earth. Fortunately, the body can compensate, or else the astronauts would fall ill.
But researchers aren’t sure how long the body can stay in this persistent state of repairing itself, especially if it’s in space on a long mission.
Even when the astronauts involved in the study came back to life in the presence of gravity, there was no quick fix. A year after they returned to Earth, it was found that they were still losing red blood cells at a higher rate.
Despite this, they were able to function normally. Both male and female astronauts have been affected.
“If we can figure out the exact cause of this anemia, there is potential to treat or prevent it, both for astronauts and for patients here on Earth,” Trudel said.
The researcher believes that the anemia caused by space travel is “similar” to that suffered by patients who spent inactive months in the intensive care departments due to diseases such as Covid-19.
The results of the study may mean that people who participate in space missions to distant planets will need to adjust their diets to include more iron, in addition to increasing the amount of calories for energy.
The researchers say that it may become necessary to examine astronauts and space tourists before flights to ensure that they do not have health conditions affected by anemia.