NASA’s twin study found that living in space affects your DNA, but what exactly that means is undetermined.
Two years ago, NASA began a unique experiment to determine what happens to the human body when it’s exposed to the zero-gravity environment of space for a long period of time. To do this, they recruited a set of twins, Scott and Mark Kelly, and sent Scott to the International Space Station for a year while Mark stayed on the ground.
When Scott got back, he and his brother were subjected to a battery of tests designed to compare their bodies in every possible way, to see what changed. Some of those results are now being released, including a new discovery about how zero gravity affected Scott Kelly at the level of his DNA.
According to the research, Scott’s DNA showed signs of excessive methylation. Methylation is the process by which cells attach chemicals called methyl groups to DNA molecules. It’s a perfectly normal process that your body uses to activate and deactivate specific genes, and your body experiences methylation all the time.
But Scott Kelly experienced methylation at a much higher rate than his brother Mark while he was in space. This is likely because his body was adjusting to the radically different environment, which could have helped him grow more accustomed to the lack of gravity.
“Some of the most exciting things that we’ve seen from looking at gene expression in space is that we really see an explosion, like fireworks taking off, as soon as the human body gets into space,” says investigator Chris Mason. “With this study, we’ve seen thousands and thousands of genes change how they are turned on and turned off. This happens as soon as an astronaut gets into space.”
With this data, scientists can better understand what happens to our bodies when we spend a long time in space. This will become extremely important in a few years or decades when we start sending people on trips to Mars or to NASA’s proposed Deep Space Gateway in orbit of the Moon.