Researchers have had a rare opportunity to see how conditions on the International Space Station translated to changes in gene expression by comparing identical twin astronauts one of the twins spent close to a year in space, while the other remained on Earth.

The environment of the space station induced changes in gene expression through a process called epigenetics. NASA scientists already know that astronauts will be affected differently by the physical stresses they experience. Studies of astronauts’ genetic backgrounds might explain why some are more susceptible to health problems when they come back to Earth.

These findings could translate to personalized preventive measures for the vulnerable astronauts. Surprisingly, it seems that these discoveries could also lead to therapy development for common syndromes affecting us on Earth.

NASA has been studying the consequences of space travel on the human body since the dawn of the space age. At a news conference held approximately a week after arriving at the International Space Station (ISS), Canadian astronaut David Saint-Jacques said he felt a “little congested” and “had a big red puffy face like the feeling you get hanging from the monkey bars.” The basis for this uncomfortable feeling relates to fluid redistribution from the lower to the upper body.

Health After long space Missions

The health effects that result from long missions in space are not well understood. Overall, astronauts remain in excellent mental and physical health relative to the general population, even after their return from long-term missions. And yet, the health consequences of such missions have been recognized, including cardiovascular deconditioning and vision problems, the causes for which are being investigated.

NASA scientists are exploring how gene expression the way DNA is converted to tissues changes in response to the environment inside the ISS. The field of epigenetics describes mechanisms through which environmental factors, like microgravity, relatively high carbon dioxide levels and possible surges in radiation alter the way DNA is read.

Researchers also want to know how each astronaut’s unique DNA will determine their response to the space station environment. Right now, of the 37 studies under way in the space station, three focus specifically on genetic research.

Genetic and epigenetic studies in astronauts promise to provide astronauts with personalized medical interventions while in space. And they could also provide those of us on Earth with potential therapies.