Does a year in space make you older or younger? The result of an experiment of NASA with twins

The amount of time that the human body can be exposed to space without putting its health at risk is one of the major obstacles to space exploration. However, a single investigation of two twin astronauts revealed that people can tolerate longer missions on the moon, and even on Mars, than previously thought, Reported in a scientific report Thursday Science

Traveling in space causes significant changes in the vital signs of a person, As well as their blood pressure, their weight, their optic nerves and even the bacteria that live in the intestinal tract, but they do not produce long-term health consequences, found the study.

Kelly twins, aged 50, were the subjects of the experiment: while Scott spent a record 340 days aboard the International Space Station, Mark – also an astronaut and candidate for the Senate of Arizona State – He stayed on Earth and served as controller.

During Scott's stay in the area, a group of researchers intensively monitored his vital signs., changes in the activity of their genes, metabolism, intestinal bacteria, the immune system and even variations in the functioning of their brains. They then compared these results with the same measures taken by their brother Mark, who showed none of the same effects..

Scientists have discovered a variety of biomedical and genetic changes in Scott's body during his adaptation to space. "Upon arriving in space, we observed thousands of genes in dynamic mutation"said Christopher Mason biophysicist Weill Cornell Medicine in New York, who badyzed the DNA of the astronaut."The gene expression data indicated six times the number of genes increasing and decreasing over the last six months of the mission compared to the first six months."

Genes related to the immune system and DNA repair have increased their activity. The bacteria that lived in your intestinal tract have changed. Cardiac output, which measures the heart rate and volume of blood pumped, increased by 10% in space. His blood pressure dropped and some arteries swelled. He lost 7% of his weight and his optic nerves swelled, affecting his vision.. According to NASA's medical experts, it is common for astronauts who travel in space with excellent eyesight to return to Earth with glbades in need of glbades.

Some changes were surprisingly positive: he seemed to think faster, specifically in measures of spatial orientation and motor accuracy, perhaps in response to weightlessness, said the scientists. Genes related to immune responses, damage repair, inflammation, and cell growth were more active in space. Telomeres, areas of DNA that typically shorten with age, lengthen in space.

"We have learned that the human body is quite resilient," Kelly said. "We can survive and even thrive on these long-haul flights."

None of the changes observed by the researchers posed a serious risk to health. Most biometric measurements of the astronaut returned to normal six months after his return to Earth. Specifically, the telomere length decreased rapidly and then stabilized over the following months to reach near-pre-flight averages. But from the point of view of aging and the risk of disease, I had a lot more short telomeres after the space mission than before.

"We had two genetically identical individuals," said Susan M. Bailey, an oncologist at Colorado State University and a specialist in telomere studies. "No matter which of the differences we saw, we could attribute it to spaceflights and not to differences between the two individuals"

While NASA plans to embark on longer journeys, one of the challenges facing space medicine experts is how to manage the health risks of these missions. The intensive study of Kelly twins, based on advanced techniques to measure the body's molecular changes during the trip, could pave the way for some kind of precision medicine for astronauts. The treatments and preventive measures that astronauts must undergo can anticipate the bodily changes they expect in space.said Bailey.

"In reality, this opens the door to the kind of badysis that could never have been done before, which will be important for astronauts when they travel to Mars for long-duration spaceflight." and that will have to be progressively independent of the resources available on Earth, "said Andrew Feinberg, Epigenetics Specialist at Johns Hopkins University and one of the leaders in research.