A team of scientists from Russia and Canada analyzed the effect of microgravity on the protein make-up in blood samples of 18 Russian cosmonauts who lived on the International Space Station for six months. They were interested particularly in their immune system’s health.
The alarming changes to the cosmonaut’s immune systems suggested that even fighting off a simple cold virus would be dangerous. The study’s conclusions were published in the journal Nature – Scientific Reports.
Professor Evgeny Nikolaev, of Moscow Institute of Physics and Technology and the Skolkovo Institute of Science and Technology, said, “The results showed that in weightlessness, the immune system acts like it does when the body is infected because the human body doesn’t know what to do and tries to turn on all possible defense systems.”
What we do know from previous studies
The effects of weightlessness or microgravity on the human body have been studied extensively since man has been going into space. We have learned that microgravity influences metabolism, heat regulation, heart rhythm, muscle tone, bone density, and the respiration system.
A study conducted in 2016 by NASA found that astronauts who traveled into deep space on lunar missions were five times more likely to have died from cardiovascular disease than those who went into low-Earth orbit or never left Earth.
Most important is that we are beginning to understand that like all organisms on Earth, we have evolved and adapted to specific living conditions. And that makes perfectly good sense. But as ZME Science points out, now we want to leave the Earth and explore an environment that is hostile to Earth-bound organisms.
Yet, with all we have learned about the environmental factors involved in space flight and their effects on the human body, it wasn’t until now that the molecular mechanisms which drive physiological changes caused by space flights have been studied.
The study – Protein expression changes
To get a better picture of the changes in human physiology during space travel, the research team quantified concentrations of 125 proteins in the blood plasma of the cosmonauts who had spent six months aboard the International Space Station (ISS).
Blood proteins are the underpinning for almost all the tasks going on inside our bodies, so we need them to be working well. So by looking at these proteins, specifically, we can tell a lot about our immune systems because the proteins change as our immune systems are altered.
In preparation for the study, blood samples were taken from the cosmonauts 30 days before they left Earth to establish a baseline, and then again, on their immediate return to Earth. A third blood sample was taken seven days after their return. Individual proteins from all three samples of each cosmonaut’s blood were then counted using a mass spectrometer.
”When we examined the cosmonauts after their being in space for half a year, their immune system was weakened,” said Dr. Irina Larina, the first author of the paper, a member of Laboratory of Ion and Molecular Physics of Moscow Institute of Physics and Technology. “They were not protected from the simplest viruses. We need new measures of disorder prevention during a long flight.”
While the effects of microgravity were manageable after only being in space for six months, the study does raise some important questions about longer journeys into space and colonizing the moon or Mars. A one-way journey to Mars could take 6-8 months, and colonists would not have the medical infrastructure available to them if needed. This means they would have to rely on their immune systems.
This is why the researchers believe we must work to further understand this problem and find some corrective measures if we are to continue to explore space.
“We must understand the mechanism that causes disorders. If we find the pathways that are affected by the weightlessness, we will be able to find the target for the remedy and we’ll be able to offer new pharmaceutical products that will prevent these negative processes,” said Dr. Larina.
