Anemia could be a challenge for astronauts, says new Canadian study
The next “giant leap” for humans could be a trip to Mars, but getting enough oxygen-carrying red blood cells for the trip could present a challenge, new research suggests.
Even space tourists queuing for short trips might have to stay home if they are at risk of anemia or red blood cell deficiency, the researchers said.
Astronauts are known to suffer from “space anemia”, but until now it was thought to be temporary. A NASA study called it a “15-day illness.”
Doctors have attributed it to the destruction of red blood cells, or hemolysis, resulting from the movement of fluids as astronauts’ bodies have adapted to weightlessness and again to gravity.
In fact, anemia is “a primary effect of going to space,” said Dr. Guy Trudel of the University of Ottawa, who led a study of 14 astronauts funded by the Canadian Space Agency. “As long as you are in space, you destroy more blood cells” than you make. “
Normally, the body destroys and replaces nearly two million red blood cells per second. Trudel’s team found that astronauts’ bodies destroyed three million red blood cells per second during their six-month missions.
“We thought we were experiencing space anemia, and we didn’t know it,” Trudel said.
The astronauts generated extra red blood cells to make up for those destroyed. But, asks Trudel, how long can the body consistently produce 50% more red blood cells? A round-trip mission to Mars would take about two years, NASA estimated.
“If you’re on your way to Mars and you can’t keep up with ‘the need to produce all those extra red blood cells,’ you could be in serious trouble,” Trudel said.
Having fewer red blood cells in space is not a problem when your body is in zero gravity, he added. But after landing on Earth, and potentially on other planets, anemia could affect the energy, stamina, and strength of astronauts.
A year after returning to Earth, astronauts’ red blood cells had not fully returned to pre-flight levels, his team reported in Nature Medicine on Friday.
Trudel is also studying the effects of immobility on patients who are bedridden for weeks or months.
The new findings mimic what he sees in his patients, he said, suggesting that what happens in space can also happen in immobile patients.
“A solution to one could also apply to the other,” he said.
Sulekha Anand, who is researching human physiology at San Jose State University and was not in the study, agreed.
“The results have implications for understanding the physiological consequences of spaceflight and anemia in patients on the ground,” she said.
Trudel’s team is looking at ways to fix the problem, he said.