Astronauts traveling to Mars may develop anemia

By Mark Waghorn

Astronauts traveling to Mars may develop anemia, warns new research.

The life-threatening condition makes sufferers feel tired and weak - and could affect the success of missions.

Being in space kills more than three million red blood cells - a second. They carry oxygen around the body.

Lead author Professor Guy Trudel, of the University of Ottawa in Canada, said: "Our study shows upon arriving in space, more red blood cells are destroyed."

He added: "This continues for the entire duration of the astronaut's mission."

The findings are based on blood samples collected from 14 astronauts aboard the International Space Station (ISS).

Participants included Chichester-born Major Tim Peake from the European Space Agency.

On Earth, our bodies create and annihilate 2 million red blood cells - every second.

Astronauts were losing 54 percent more red blood cells during the six months they were on the ISS.

It applied to both female and male crew members, say the Canadian team.

Anemia is also known as low haemoglobin. The protein transports oxygen to organs. Without enough, the skin can turn pale.

The study, published in the journal Nature Medicine, is a world-first, explaining a mystery that has puzzled scientists for 65 years.

Dr Trudel said: "Space anemia has consistently been reported when astronauts returned to Earth since the first space missions - but we didn't know why."

It was believed to be a quick adaptation to fluids shifting into the upper body upon arrival in zero gravity.

Astronauts lose 10 percent of liquid in blood vessels this way. It was thought 10 percent of red blood cells also quickly disappeared - and returned to normal after 10 days.

But the researchers found the destruction was a primary effect of being in space - not just fluid shifts.

Tiny amounts of carbon monoxide in breath samples from astronauts were also measured.

They are produced every time a single molecule of heme, the pigment in red blood cells, is destroyed.

Dr Trudel said: "Thankfully, having fewer red blood cells in space isn't a problem when your body is weightless.

"But when landing on Earth and potentially on other planets or moons, anemia affecting your energy, endurance and strength can threaten mission objectives.

"The effects of anemia are only felt once you land, and must deal with gravity again."

In the study, five out of 13 astronauts were clinically anaemic when they landed. The other did not have blood drawn on landing.

The researchers saw space-related anemia was reversible, with red blood cells levels progressively returning to normal three to four months after returning to Earth.

But the same experiments a year later found red blood cell destruction was still 30 percent above preflight levels.

Structural changes may have happened that changed control for up to 12 months after long-duration missions.

The discovery that space travel increases red blood cell destruction has several implications.

It could lead to the screening of astronauts or space tourists for existing blood or health conditions that are affected by anemia.

A recent study by Dr Trudel's team found the longer the space mission, the worse the anemia.

This could impact long missions to the Moon and Mars. Increased red blood cell production will require an adapted diet for astronauts.

Anemia affects more than a quarter of the world's population. It is caused by iron deficiency.

It is also unclear how long the body can maintain this higher rate of destruction and production of red blood cells.

As a rehabilitation physician, most of Dr Trudel's patients are anaemic after long illnesses with limited mobility.

It hinders their ability to exercise and recover. Bedrest has been shown to cause anemia, but how it does this is unknown.

Dr Trudel thinks the mechanism may be like space anemia. His team plan to investigate the hypothesis.

He said: "If we can find out exactly what is causing this anemia, then there is a potential to treat it or prevent it, both for astronauts and for patients here on Earth."

The study in Nature Medicine is the first from MARROW, a project funded by the Canadian Space Agency.

Dr Trudel added: "This is the best description we have of red blood cell control in space and after return to Earth.

"These findings are spectacular, considering these measurements had never been made before and we had no idea if we were going to find anything. We were surprised and rewarded for our curiosity."

Last year a study of ISS astronauts found going to Mars could change fluids in the brain - increasing the risk of Alzheimer's.

A round trip to the Red Planet will take 21 months - including 18 months there and back.

It is known being in space weakens bones and muscles, harms vision and alters gut bacteria that boost the immune system.

The race to Mars is hotting up. China hopes to beat the US with the first manned mission planned for 2033. It wants to build a base there.

It is rich in iron, silicon and other metals and minerals that governments across the world want to plunder.

NASA has been developing technology to get a crew to Mars and back sometime in the 2030s.