Published: Sun, April 14, 2019
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NASA Twins Study decodes space impact on human body

NASA Twins Study decodes space impact on human body

Scott was based at the International Space Station (ISS) for a just under year, whilst Mark remained on Earth.

The findings from the study were published April 12 in the journal Science. The results are mixed - Kelly fared better than expected on some measures and worse on others.

Steven Platts, NASA Human Research Program deputy chief scientist, said on a conference call to release the study that the results show "the resilience and robustness of the human body".

NASA released the results of a momentous twin study on Thursday, which found that space travel has profound effects on the human body. NASA called the findings "interesting, surprising and reassuring", detailing the changes in Kelly's body caused by his almost year-long time on the International Space Station. "If we decide to go to Mars someday with people, that's going to be a two-and-a-half year trip, and I hope we do it, I hope we do it soon". Mark underwent identical tests. Strangely, the average length of Kelly's telomeres increased in space, rather than decreasing, as if his cells were becoming more youthful.

There was also a spike in circulating markers of inflammation, especially so called c-reactive proteins (CRP), which are predictive of cardiovascular problems. From his eyes to his immune system, Scott's body sometimes reacted strangely to almost a year in orbit, at least compared to his Earth-bound brother _ but research published on Thursday, April 11, 2019 shows nothing that would cancel even longer space treks, like to Mars.

His immune system took a hit too.

When astronaut Scott Kelly landed in the frigid Kazakhstan plains on March 2, 2016, a team of responders pulled Kelly and two Russian cosmonauts from the charred capsule and carried them to chairs, set out in the crisp morning air. Spending a year on the space station would shock anyone's system. A fully functioning immune system during long-duration space missions is critical to protecting astronaut health from opportunistic microbes in the spacecraft environment.

The good news was, Kelly's immune profile returned more or less to baseline after he came home.


As an experiment both brothers were given a flu vaccine, which produced similar results.

The impact of space on the genome was even more dramatic-and it happened fast. Their genes aren't exactly the same, but they're about as close as we can get without a direct Kelly clone, providing a way to understand how space changes the very stuff that makes us up: DNA. "They included things that affect DNA maintenance and fix, as well ramping up the immune system when it's needed". Many of these biological changes seemed harmless, disappearing after he returned to Earth. "At a point nine months after return, we still saw elevated inversions".

A team with Johns Hopkins University identified a less than 5 percent difference in overall methylation, a process of chemical modifications in gene expression, in the twins' white blood cells. That research mostly involves telomeres, the nucleic sequences at the end of chromosomes that protect them from damage the way a plastic aglet protects the tip of a shoelace. Long-term effects of research, such as the ongoing telomeres investigation, will continue to be studied. "We don't have much experience with people leaving that protective shell". "We're seeking correlations that can explain how this is happening". Scientists aren't sure why the telomeres of the Kelly brother who was in space got longer, and are interested in finding out why moving forward.

"Do not think of telomere lengthening as a fountain of youth", warns Bailey.

But in space, Scott Kelly's telomeres got longer. "He travels around, he golfs, his diet changes, and that is a big difference".

Scientists noted changes in the expression of Scott Kelly's genes while in space, with most - but not all - returning to normal after six months back on Earth. His performance on cognitive tests improved throughout much of the mission, but performance on tests created to measure his ability to recognize emotions in other people declined.

Scott experienced some changes to his vision and the shape of his eyeball, including a thicker retinal nerve and folds in the choroid layer that surrounds the eye, possibly due to the effects of zero gravity on fluids in the body.

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