Space agencies are working on several of the challenges astronauts face in space, such as reliable communications and fuel management, and a new threat has just been added to the list: anemia.
A study conducted by researchers in Ottawa found that astronauts’ bodies destroy 54 percent more red blood cells in space than when they’re on the ground.
On Earth, our bodies make and destroy 2 million red blood cells every second, but researchers found that during six months in space, they destroyed 3 million per second.
Doctors attributed it to red blood cell destruction or hemolysis, due to fluid shifts as astronauts’ bodies adapted to weightlessness and again because they re-adapted to gravity.
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A study conducted by researchers in Ottawa found that astronauts’ bodies destroy 54 percent more red blood cells in space than when they’re on the ground
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’re in space, you’re destroying more blood cells” than you create.”
But just as our bodies make red blood cells to compensate for the blood cells they destroy while on Earth, astronauts’ bodies do the same.
But, Trudel asked, how long can the body consistently make 50 percent more red blood cells?
A return flight 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 make all those extra red blood cells,” you could be in serious trouble,” Trudel said.
Doctors attributed it to red blood cell destruction or hemolysis, due to fluid shifts as astronauts’ bodies adapted to weightlessness and again because they re-adapted to gravity. Tim Peake had his blood drawn aboard the International Space Station for the study
Having fewer red blood cells in space isn’t a problem if your body is weightless, he added. But after landing on Earth, and possibly other planets, anemia can affect astronauts’ energy, stamina and strength.
A year after returning to Earth, the astronauts’ red blood cells were not quite back to pre-flight levels, his team reported Friday in Nature Medicine.
The new findings mimic what he sees in his patients, he said, suggesting that what happens in space could also happen in immobile patients.
“A solution for one person can also work for another,” he said.
Sulekha Anand, who studies human physiology at San Jose State University and was not involved in the study, agreed.
On Earth, our bodies make and destroy 2 million red blood cells every second, but researchers found that during six months in space, they destroyed 3 million per second. Experts wonder how long the body can consistently produce 50 percent more red blood cells. Pictured is David Saint-Jacques having his blood drawn aboard the International Space Station
“The findings have implications for understanding the physiological consequences of spaceflight and anemia in patients on the ground,” she said.
A separate March 2021 study revealed that long space flights can make the heart shrink, which could be a worrying finding for the next generation of astronauts.
Even a long-term program of low-intensity exercise in space isn’t enough to counteract the effects of prolonged weightlessness on the heart, say researchers at the University of Texas Southwestern Medical Center.
Both men lost mass in their left ventricle — one of the two large chambers on the underside of the heart — over the duration of their campaigns, despite significant amounts of exercise, the researchers found.
Microgravity in space means the heart doesn’t have to work as hard to pump blood around the body, causing atrophy — a reduction in tissue.
It poses a serious problem for astronauts during extended space flights because it decreases bone density, increases the risk of bone fractures and degrades muscles.
The study’s leader, Professor Benjamin D. Levine of the University of Texas Southwestern Medical Center, said in a statement, “The heart is remarkably plastic and responds primarily to gravity or its absence.
“Both the impact of gravity and the adaptive response to exercise play a role, and we were surprised that even extremely long periods of low intensity did not prevent the heart muscle from shrinking.”
HOW DOES SPACE RADIATION INFLUENCE THE HEALTH OF ASTRONAUTS?
Astronauts traveling to Mars would likely be bombarded with 700 times the radiation levels experienced on Earth.
Even on the International Space Station, astronauts are exposed to 200 times more radiation through their work than a pilot or a radiology nurse would experience.
As a result, NASA is constantly monitoring local space weather information.
If a burst of space radiation is detected, mission control in Houston, Texas, could instruct astronauts to abort spacewalks, move into more shielded areas of the orbiting lab, and even adjust the station’s elevation. to minimize any health effects.
The activity of solar flares can cause acute effects of radiation exposure — such as blood changes, diarrhoea, nausea and vomiting — that are reversible, and other effects that are irreversible and/or fatal.
Prolonged cosmic ray bombardments are of greater concern.
This can increase the risk of cancer, cause cataracts and cause sterility.
It can also damage the brain, central nervous system, and heart, paving the way for various degenerative diseases.
DNA changes from space radiation can even be passed on to subsequent children.