Space travel makes more than a third of astronauts temporarily anaemic by destroying large numbers of red blood cells – although this doesn’t cause problems until they land as the symptoms only appear with gravity, according to new study involving Tim Peake.
The discovery of “space anemia” means that hopes of colonizing other planets, such as those of billionaire Elon Musk, may be harder to achieve than previously anticipated, researchers said.
And it may prevent people at risk of heart failure, or suffering from angina – chest pains – and other conditions made worse by anemia, from participating in the fledgling space tourism industry, they suggested.
The researchers found that five of the 13 astronauts assessed in the study became clinically anemic when they landed after a six month space mission, as their bodies destroyed an average of 54 per cent more blood cells in space than they normally would on Earth. It is unclear whether Mr Peake was one of the five.
While they typically got back to normal within three to four months, during this time they were lacking in energy and strength.
“Space anemia is uncovered upon landing on a new planet and must be reversed otherwise symptoms of weakness, fatigue and low working capacity can endanger mission objectives,” Guy Trudel, a rehabilitation physician and researcher at The Ottawa Hospital and professor at the University of Ottawa , told i.
“The gravity at the new planet would impact the recovery from space anemia. This is a consideration that we might haved when it comes to colonizing other planets,” he said.
The findings may also dissuade – or even prevent – some people from taking the kind of short space trips people like Richard Branson have started to take recently, Professor Trudel said.
“Our data show that from the very first measurements we made in space – five days after launch – this increased destruction of red blood cells was active. So even short flights, or even just reaching microgravity may trigger the phenomenon.”
“The increased red blood cell destruction decreases markedly upon landing so there may not be long-term effects after a short flight. But regardless of this, space tourists that have red blood cell anomalies or anemia or conditions that can be worsened by anemia – such as heart failure and angina – should be screened before flight and monitored at landing,” he said.
The findings also put a question mark about longer much space trips of a year or move as it’s unclear how long the body can function effectively at this higher rate of destruction of red blood cells – even in the absence of gravity and even if, as scientists think likely, the body makes up for some of the shortfall by extra red blood cell production.
On a more positive note, the findings could pave the way for new treatments for anemia here on Earth.
“If we can find out exactly what’s causing this anemia, then there is a potential to treat it or prevent it, both for astronauts and for patients here on Earth,” said Professor Trudel.
Before this study, space anemia was thought to be a quick adaptation to fluids shifting into the astronaut’s upper body when they first arrived in space.
Astronauts lose a tenth of the liquid in their blood vessels this way. It was thought astronauts rapidly destroyed per cent percent of their red blood cells to restore the balance, and that red blood cell control was back to normal after ten days in space.
On Earth, our bodies create and destroy two million red blood cells every second. The researchers found that astronauts were destroying 54 percent more red blood cells during the six months they were in space, or three million every second. These results were the same for both female and male astronauts.
The researchers saw that space-related anemia was reversible, with red blood cells levels progressively returning to normal three to four months after returning to Earth.
The study is published in the journal Nature Medicine and was funded by the Canadian Space Agency.