We Finally Know The True Extent of Space Destroying Astronauts' Red Blood Cells - ScienceAlert

Since our species first started to spend extended periods of time beyond our planet, researchers have noticed a curious and consistent loss of red blood cells among astronauts.

During a six-month space mission flight, researchers found the human body destroys about 54 percent more red blood cells than it normally would.

When the astronauts were in space, the loss of red blood cells appears to have led to a higher-than-normal circulation of iron serum in their blood. Without as many red blood cells to transport iron around the body, the astronauts gradually approached anemia, which can be classified into mild, moderate, and severe.

When they returned to Earth, five out of 13 astronauts (one didn't get blood drawn on landing) had reached clinically diagnosable levels of anemia, defined as the condition where the body doesn't have enough red blood cells for its physiological needs.

But even a year after their space flight was done, the astronauts' bodies were still destroying 30 percent more red blood cells than before their trip to space.

The study didn't measure red blood cell production, but given that no astronaut suffered severe anemia, despite the significant losses of red blood cells, their bodies may also have been producing more red blood cells than normal while in space.