The news: The NASA Twins study famously compared changes in the body of astronaut Scott Kelly while on the International Space Station for a year with that of his twin brother Mark who stayed on Earth. It provided evidence for what we already suspected—that in space the immune system takes a hit, and muscle and bone mass drop—but it also showed some surprising effects, like slower cognitive abilities, certain genes switching off and on, and changes in the gut microbiome. New research published this week reanalyzed the data from that study, and provided comparisons with other astronauts.
What it found: Across 19 new studies, which incorporate results from cell-profiling and gene-sequencing techniques that have become easier to run only recently, the researchers highlight six biological changes that occur in all astronauts during spaceflight.These are: oxidative stress (an excessive accumulation of free radicals in the body’s cells), DNA damage, dysfunction of the mitochondria, changes in gene regulation, alterations in the length of telomeres (the ends of chromosomes, which shorten with age), and changes in the gut microbiome.
What does it mean? Ultimately, the data highlights just how much havoc and stress even the healthiest bodies face during space missions—which should have an impact on planning for longer missions. “I don’t think we’re close to sending untrained people into space for really long periods of time,” says Scott Kelly. But they could also give scientists clues on how to mitigate those changes. Read the full story.