When we’re on Earth, our our bodies create and destroy 2 million of those cells per second. In house, astronauts skilled 3 million purple blood cells destroyed per second, leading to a lack of 54% extra cells than folks on Earth experience, in keeping with a brand new examine.
Lower purple blood cell counts in astronauts is named house anemia.
“Space anemia has persistently been reported when astronauts returned to Earth because the first house missions, however we did not know why,” stated examine creator Dr. Guy Trudel, a rehabilitation doctor and researcher at The Ottawa Hospital and professor on the University of Ottawa, in an announcement.
Researchers took breath and blood samples from 14 astronauts earlier than their six-month stays on the International Space Station. The astronauts additionally took samples 4 instances throughout their flights. The researchers additionally collected blood from the astronauts as much as a yr after their spaceflight.
A stunning discover
When astronauts are in house, they experience a shift of bodily fluids towards the higher physique as a result of lack of gravity. This leads to elevated strain on the mind and eyes, inflicting cardiovascular points and a lack of 10% of the liquid of their blood vessels.
Researchers believed that house anemia was the physique’s method of adapting to the fluid shift, ensuing within the destruction of purple blood cells to revive the stability. They additionally thought that the purple blood cell loss was solely momentary, restoring itself after the astronauts adjusted after spending 10 days within the house surroundings.
Trudel and his staff found a stunning end result — the house surroundings is the precise perpetrator.
“Our examine exhibits that upon arriving in house, extra purple blood cells are destroyed, and this continues for all the length of the astronaut’s mission,” he stated.
The analysis staff developed methods to measure purple blood cell destruction, together with measuring the quantities of carbon monoxide detected in breath samples from the astronauts. Each time one molecule of heme, or the signature purple pigment in purple blood cells, is destroyed, it creates a molecule of carbon monoxide.
The staff was unable to straight measure the manufacturing of purple blood cells within the astronauts, however they count on that the astronauts skilled the technology of additional purple blood cells in response to elevated destruction. If this had not occurred, all the astronauts would have suffered the results and well being points related to extreme anemia whereas in house.
“Thankfully, having fewer purple blood cells in house is not an issue when your physique is weightless,” Trudel stated. “But when touchdown on Earth and probably on different planets or moons, anemia affecting your vitality, endurance and energy can threaten mission targets. The results of anemia are solely felt when you land, and should take care of gravity once more.”
After returning to Earth, 5 of 13 astronauts have been recognized as clinically anemic. One of the astronauts didn’t have a blood draw after touchdown.
Follow-up samples taken from the astronauts confirmed that house anemia is reversible as a result of their purple blood cell counts progressively returned to regular between three to 4 months after their return.
However, samples collected a yr after the astronauts landed on Earth confirmed that the speed of purple blood cell destruction was nonetheless elevated, about 30% above what they skilled earlier than their spaceflight.
The researchers imagine this means that long-duration house missions might lead to structural modifications that influence purple blood cells.
For now, it is unsure how lengthy the human physique can help an elevated price of each destruction and manufacturing of purple blood cells.
In order to fight this danger, the researchers recommend that astronaut diets be modified to help higher blood well being.
The classes realized from this analysis may be utilized to anemia sufferers on Earth, particularly those that experience it after sickness and extended mattress relaxation. While the direct reason for this sort of anemia is unknown, it could be much like what occurs in house.
“If we will discover out precisely what’s inflicting this anemia, then there’s a potential to deal with it or stop it, each for astronauts and for sufferers right here on Earth,” Trudel stated. “This is the most effective description we have now of purple blood cell management in house and after return to Earth. We have been shocked and rewarded for our curiosity.”