There is a long-standing assumption that astronauts somehow develop some type of “space anemia” that affects them as they venture out into space, mainly due to results from blood tests that are taken after they land back on Earth. However, there hasn’t been any comprehensive data on this phenomenon. And so, a team of researchers set out to clear things up on the matter once and for all.

The study, which was conducted by Dr. Brian Crucian and his colleagues at the National Aeronautics Space Agency (NASA), is titled, “Alterations in hematologic indices during long-duration spaceflight.” It focuses on finding out exactly how much change occurs in the blood of astronauts when comparing pre-flight, in-flight, and post-flight conditions. Once all of the data available was analyzed, the researchers were able to find some pretty interesting results.

According to Dr. Richard Simpson and associate professor at the University of Arizona and the University of Houston, the assumption about anemia in astronauts is quite a pervasive one, but that it may not be rooted on much real science. “There is an idea of ‘space anemia’ that is associated with space flight,” he explained. “However, this is based on blood samples from astronauts collected after flight, which may be influenced by various factors, for example the stress of landing and re-adaptation to conditions on Earth.” He said the new study allowed them to use unique blood samples that showed hematological parameters, like concentrations of red blood cells (RBCs), hemoglobin, or hematocrit – all from astronauts onboard the International Space Station (ISS).

In a somewhat surprising twist, the researchers found that going out into space increases the concentrations of RBCs in astronauts – at least initially – before it finally settles on a stable level after a while. Instead of dipping, in fact, the RBC counts and other factors that might be related to anemia were found to be more stable during spaceflight, according to the data the researchers gathered. This is great news for the astronauts as well as NASA, which is currently planning to send men into longer-duration flights out in space. The knowledge and information gathered from this research could even prove useful for interplanetary flights, like the one the agency plans for Mars.

According to Kathleen McMonigal, a co-author on the study and a pathologist and director of clinical laboratories at NASA’s Johnson Space Center, it’s important to make sure that astronauts are not going to be impaired during their missions out in space. “If our astronauts start landing other places like on the moon, or [on] Mars, if they get off the spaceship and they don’t have enough red cells, they’re going to get very winded and fatigued,” she said in a statement to Space.com. Astronauts should be in their absolute tip-top shape to go off and explore the surrounding terrain after landing to make the most out of their trips.

Dr. Crucian, the lead author of the study, also shared some of his thoughts: Although the results were surprisingly positive, he said that it would still be necessary to analyze blood plasma levels directly to put things into context better. It is said that the crew plasma volume during flight may be directly related with the levels of RBCs recorded, and that is why they need to clear that particular matter up first before drawing any real conclusions.

The idea that space anemia is just an old wives’ tale is highly encouraging and gives hope that NASA can indeed send humans out into the farthest reaches of space with minimal worries. But of course, other potential issues might arise, so it’s a good thing that they are continuing their research to make sure that they’ve got all their bases covered.

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Sources include:

SpaceRef.com

BMCHematol.BiomedCentral.com

Space.com