Astronauts’ bodies undergo plenty of stress beyond just the extraordinary g-forces at launch. Microgravity, cosmic radiation, biological clock disruptions, and more all take a toll on space travelers. Now, new research is shedding light on how these invisible stressors can prematurely age astronauts—and how they can bounce back.
Scientists David Furman and Matias Fuentealba of the Buck Institute took blood samples from four astronauts before, during, and after a 10-day trip to low Earth orbit on the Axiom-2 mission. Working in concert with laboratories in New York City and Saudi Arabia, they developed what they call the “Epigenetic Age Acceleration” (EAA) formula to measure how gene expression and biological age are altered by spaceflight. They published their findings in Aging Cell.
Read more: “Physics Makes Aging Inevitable, Not Biology”
Overall, the team studied 32 different DNA methylation-based clocks and determined the astronauts’ epigenetic age had advanced almost two years by day seven of their trip, then quickly recovered once they were back on Earth. In fact, younger astronauts showed a biological age that had actually dropped below their pre-flight measurements.
“These results point to the exciting possibility that humans have intrinsic rejuvenation factors that can counter these age-accelerating stressors,” Furman explained in a statement. “Using spaceflight as a platform to study aging mechanisms gives us a working model that will allow us to move toward the ultimate goal of identifying and boosting these rejuvenating factors both in astronauts and in those of us planning on aging in a more conventional manner.”
In the meantime, Furman is studying the effects of microgravity on heart, brain, and immune cells in his lab on Earth, all in an effort to delay our inevitable trip to the final frontier. 
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