NASA's Mark, Scott Kelly ‘Twin Study' reveals possible stress of long space stay

Study reveals what year in space does to human body

Identical twins, Scott and Mark Kelly, were the subjects of NASA's Twins Study. Scott (left) spent a year in space while Mark (right) stayed on Earth as a control subject. Researchers are looking at the effects of space travel on the human body. (NASA)

The first set of results for NASA’s "Twin Study" of astronaut Scott Kelly and retired astronaut Mark Kelly are in, revealing the impact a longtime stay in space could have on the human body.

Mark Kelly acted as the control subject, starting in March 2015, on Earth, while Scott Kelly spent 340 days on the International Space Station. Scientists collected samples from both subjects before, during and after Scott Kelly’s NASA mission.

Preliminary study results were announced last week in Texas at NASA’s Human Research Program’s annual Investigators’ Workshop.

The chemical marker to DNA that can affect gene expression, DNA methylation, decreased while Scott Kelly was in space and increased in Mark on Earth, according to a study led by Andrew Feinberg, a geneticist at Johns Hopkins University School of Medicine.

The results could mean genes are sensitive to a changing environment, according to NASA, but will require more analysis to confirm that theory.

In a Biochemical Profile investigation, a decline in bone formation was observed during the second half of Scott Kelly’s stay on the space station. C reactive protein levels, a widely accepted marker for inflammation, spiked after Scott Kelly landed and could be related to the “stresses of reentry and landing,” according to NASA.

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Scott and Mark Kelly’s DNA and RNA showed hundreds of unique mutations in their genome. Further study will determine if a “space gene” could have been activated while Scott Kelly was in space, NASA said.

Further research on the data collected during the first ever study of two genetically identical humans with one in a zero-gravity environment is still needed but the full results may not ever be released.

The twins will review all the findings before they are published to avoid revealing any genetic predisposition they don’t want made public.

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