Humans as a species have not been exploring space for so long. We also do not know exactly the possible repercussions that space travel can have on our health . A new study has concluded that the prolonged periods astronauts spend outside of Earth could increase the risk of brain damage.
The study is small and has been carried out with only five astronauts, who underwent a blood test before and after spending a prolonged stay on the International Space Station (ISS), an average of 169 days in orbit each cosmonaut. In blood samples taken after returning to Earth, the researchers observed elevated concentrations of three biomarkers related to brain damage : NFL, GFAP, and the amyloid beta protein Aβ40.
“This is the first time that concrete evidence of damage to brain cells has been documented in blood tests after spaceflight,” says neuroscientist Henrik Zetterberg of the University of Gothenburg (Sweden). In previous studies on the same subject, space travel has been linked to decreased cortical volume or brain shrinkage, further evidence of a problem that requires further investigation. “You have to keep exploring and preventing this if space travel is to become more common in the future ,” Zetterberg said.
The biomarkers that have been analyzed have been light neurofilament (NFL), glial fibrillar acidic protein (GFAP), total tau (T-tau) and two beta amyloid proteins. NFL, GFAP, and amyloid beta protein Aβ40 were the biomarkers that rose after a prolonged stay in orbit on the ISS. It is not known to what extent, if any, the brains of the astronauts studied will be damaged, but it is known that these biomarkers have been extensively and in multiple studies linked to neurological disorders.
MRIs and clinical tests of cosmonauts’ brains support the idea that brain function could be affected by space travel, but the research is still in an early stage. More data from more people will be needed to find out exactly how and why time in space negatively affects the brain.
“If we can figure out what is causing the damage, the biomarkers we have developed could help us find the best way to remedy the problem,” says Zetterberg. The astronauts did not present the same maximum amount of biomarkers, but their elevation was common to all of them. That three biomarkers show similar changes indicates an increased risk.
This very limited study does not explain why these changes occur in the brain . No general conclusions can be drawn from data obtained from just five astronauts who were on the ISS at any given time. However, it is possible to continue research on Earth and not necessarily in astronauts since scientists can create conditions that would occur in space, such as the most stressful of a space trip. “We need to help ourselves figure out why the damage is occurring,” says Zetteberg. “Is it weightlessness, changes in brain fluid, or stressors associated with launching and landing, or is it caused by something else? Here you can do a lot of exciting experimental studies in humans on Earth. “
Fuente: zu Eulenburg P, Buchheim J, Ashton NJ, et al. Changes in Blood Biomarkers of Brain Injury and Degeneration Following Long-Duration Spaceflight. JAMA Neurol. Published online October 11, 2021. doi:10.1001/jamaneurol.2021.3589
