Humanity’s next “giant leap” could be a trip to Mars, but getting enough oxygen-carrying red blood cells for the journey could present challenges, new research suggests.
Even space tourists lining up for short trips may have to stay home if they are at risk for anemia or a lack of red blood cells, the researchers said.
Astronauts have been known to experience “space anemia,” but until now it was considered temporary. A NASA study called it “the 15-day disease.”
Doctors attribute it to the destruction or hemolysis of red blood cells, which is caused by changes in fluids as the astronaut’s body adapts to weightlessness and readjusts to gravity.
In fact, anemia is “the main effect of going to space,” said Dr. Guy Trudell 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 destroy more blood cells than you make.”
Normally, the body destroys and replaces nearly 2 million red blood cells every second. Trudell’s team found that astronauts’ bodies destroyed 3 million red blood cells per second during the six-month mission. “We thought we knew about space anemia, but we didn’t,” Trudell said.
Astronauts produced extra red blood cells to compensate for the destroyed red blood cells. But, Trudell asks, how long can the body continue to produce more than 50 percent of its red blood cells? NASA estimates that the mission to and from Mars will take about two years.
“If you’re on your way to Mars…you can’t keep up” with the need to produce all these extra red blood cells, “you could be in serious trouble,” Trudell said.
When your body is weightless, the reduction in red blood cells in space isn’t a problem, he added. But after landing on Earth, and possibly on other planets, anemia could affect astronauts’ energy, stamina and strength.
A year after returning to Earth, the astronauts’ red blood cells had not fully returned to their pre-flight levels, his team reported Friday in the journal Nature Medicine.
Trudell also looked at the effects of immobility in patients who were bedridden for weeks or months.
He said the new findings mimic what he sees in patients, suggesting that what happens in space can also happen to patients with reduced mobility.
Complete News Source : India Today
