The next ‘giant leap’ for humans could be a trip to Mars, but having enough red blood cells to carry oxygen for the journey could be a challenge, new research suggests. .
Even space tourists queuing for short trips may have to stay home if they are at risk for anemia or a shortage of red blood cells, the researchers say.
Astronauts are known to experience “space anemia” but until now it was thought to be temporary. One NASA study called it “15-day pain.”
Doctors think it causes the destruction of red blood cells, or hemolysis, due to fluid changes as astronauts’ bodies adapt to weightlessness and again when they become weightless. back with gravity.
In fact, anemia is “the main effect of going into 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’re in space, you’re destroying more blood cells” than you’re generating. “
Normally, the body destroys and replaces nearly 2 million red blood cells every second. Trudel’s team discovered the astronauts’ bodies were losing 3 million red blood cells every second during their six-month mission.
“We thought we knew about space ischemia, but we didn’t,” Trudel said.
The astronauts created extra red cells to compensate for the damaged cells. But, Trudel asked, how long can the body continuously produce 50% more red blood cells? NASA estimates that a round-trip mission to Mars will take about two years.
“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.
He added: “Having fewer red blood cells in space is not a problem when your body is weightless. But after landing on Earth and potentially on other planets, anemia can affect astronauts’ energy, endurance, and strength.
A year after returning to Earth, the astronauts’ red blood cells have yet to fully return to pre-flight levels, his team reported Friday in the journal Nature Medicine.
Trudel also studied the effects of immobilization on patients who were bedridden for weeks or months.
The new finding, he said, mimics what he sees in his patients, which suggests that what happens in space can also happen in immobile patients.
“A solution to one may also apply to the other,” he said.
Sulekha Anand, who studies human physiology at San Jose State University and was not involved in the study, agrees.
“These findings have implications for understanding the physiological consequences of space flight and anemia in patients on the ground,” she said.
Trudel’s team is working on how to solve the problem, he said.
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