The Twins Study conducted by the National Aeronautics and Space Administration (NASA) verifies that a year in space can change your DNA. The findings were published by NASA on March 15, 2018.



Kelly Twins: Subjects of the Study

Identical twin astronauts Scott Kelly and Mark Kelly were the subjects of the Twins Study. Astronaut Scott Kelly spent a year in space aboard the International Space Station, while his identical twin Mark Kelly remained on earth as a control subject.

NASA scientists monitored Scott and looked at what happened to him before, during and after his year in space.

The Study
• Scientists measured Scott's Metabolites which are necessary for maintaining life, Cytokines that are secreted by immune system cells and Proteins to track physical changes in him.

• They also studied the chemical changes in the twins DNA and RNA and found each twin had hundreds of unique mutations in their genome.

Preliminary Results
• The preliminary results of the study showed that the Scott’s DNA did not fundamentally change, however, the twins were no longer the same genetically. 

• There were changes in his gene expression, which is how the body reacts to environment. The change in gene expression, probably, occurs when humans are under stress such as during mountain climbing or SCUBA diving.

• Around 7 per cent of Scott's gene expression did not normalise after his return to Earth in 2016. Scott had oxygen-deprivation stress, increased inflammation and dramatic nutrient shifts that affect gene expression. 

• Though 93 per cent of Scott's DNA returned to normal once he was back on Earth, whereas, several space genes remained within him.

NASA’s Human Research Program

• The Twins Study was conducted under the NASA’s Human Research Program.

• The results from the study were first released in January 2018 at the Investigator's Workshop for NASA's Human Research Programme.

• The Human Research Program is aimed at discovering the best methods and technologies to support safe human space travel. 

• It enables space exploration by reducing the risks to astronaut health and performance using ground research facilities and the International Space Station. 

• It supports innovative, scientific human research by funding more than 300 research grants to respected universities, hospitals and NASA centres to over 200 researchers in more than 30 states.