Part 1 of 2 Parts
I have written before about the negative effects on the human body that result from living in space. Researchers have been exploring how spaceflight can have a serious impact on human physiology and human health. The groundbreaking Twins study found a number of ways that space travel changes human bodies. It can even have an impact on gene expression. It has been shown that the heart, eyes, and bones can be damaged. Much less attention has been paid to the effect of space travel on the human brain.
Since the days of the U.S. space shuttle missions, astronauts have reported problems with vision after time is spent in orbit. Medical evaluations of returning astronauts have reveals that astronauts’ optic nerves swell and some subjects have experienced retinal hemorrhage and other structural changes to the eyes. Scientists suspect that these vision issues are caused by increased “intercranial pressure” or pressure in the head during time in orbit.
This research team used magnetic resonance imaging (MRI) on eleven astronauts before and after they traveled in space for up to year after their return. These MRI images indicated that during long exposure to microgravity the brain swells and cerebrospinal fluid which surrounds the brain and spinal chord increases in volume.
Recently, researchers tracked the physical well-being of five Russian cosmonauts that spent about five months on the International Space Station. Elevated levels of particular proteins in the blood of the cosmonauts that serve as a marker for damage to their brains were found.
This research was documented in the October 11th edition of the journal JAMA Neurology. The number of occupants was small for a medical study and the amount of damage caused to their brains was not a major threat to their health. However, this study was sufficient to raise warning flags and it will likely be repeated with larger groups as people begin to spend longer times in space.
Henrik Zetterberg, is a neurochemist at the University of Gothenburg in Sweden and one of the authors of the brain damage research article. He said, “It's not like major traumatic brain injury or anything like that. But still, all of the cosmonauts have this pattern of biomarker change." He compared the damage to that suffered as a result of a concussion.
The researchers took blood samples from five Russian male cosmonaut twenty days before they were launched to rendezvous with the ISS in order to establish a baseline for targeted blood proteins. Then they collected additional blood samples one day, one week and three weeks after the cosmonauts returned from orbit. The team analyzed the blood samples for the quantities of five different biomarkers association with brain damage on Earth. Among the monitored proteins were two types of amyloid-beta proteins which build up and form clumps in the brains of people with Alzheimer disease. Zetterberg said, “It's a sticky protein. It is important to get rid of it from the brain tissue. In young and healthy people, it is rapidly cleared from the brain.”
Please read Part 2 next