Twin Study Suggests Human Health Can Be 'Mostly Sustained' For A Year In Space

This is a good sign for astronauts.

A NASA study of astronaut Scott Kelly and his twin brother Mark suggests that living in space can change the human body, but a healthy life can be "mostly sustained" for a year in space.

Scott, who spent 340 days aboard the International Space Station from 2015 to 2016, participated in the study by letting researchers compare his body to Mark's during his time in space and when he returned. During his time in space, Scott's carotid artery thickened and his DNA was damaged, according to CNN. He also had reduced cognitive abilities and a shift in gut microbes, the research found. The experience did not alter or mutate his DNA, though. And because Scott never left the safety of the space station, he wasn't exposed to deep-space radiation. 

The 84 scientists who helped execute the study concluded that the changes returned to normal when Mark came back from the space station. 

"When we go into space and experience microgravity and travel at speeds like 17,500 miles an hour, our bodies adapt and continue to function and, by and large, function extremely well," Steven Platts, deputy chief scientists for NASA's Human Research Program, told CNN.

While the study only reflects the impact on Scott's body, the scientists are hopeful it's indicative that future astronauts will be able to stay in space for prolonged periods of time.  

"The Twins Study has been an important step toward understanding epigenetics and gene expression in human spaceflight," J.D. Polk, chief health and medical officer at NASA Headquarters, told CNN. "This has helped inform the need for personalized medicine and its role in keeping astronauts healthy during deep space exploration, as NASA goes forward to the Moon and journeys onward to Mars."

Cover image via NASA / Robert Markowitz.


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