Do Astronauts Age Faster In Space Or On Earth?

A new study indicates that an astronaut who spent almost a year in the International Space Station (ISS) could reverse one of the aging processes. This shows the changes of astronaut's body including his "telomeres," which will appear shorter as a person gets older, but not in the case of living in space.

The new study involved NASA's astronaut Scott Kelly, who spent 340 days on the International Space Station in 2015 and 2016. The researchers examined the changes in Kelly's body while spending his life in space during the said period. He is compared to those changes experienced by his twin brother Mark Kelly, who is a retired NASA astronaut.

The results of the study surprised the scientists. They found that Scott's telomeres on the ends of the chromosomes in his white blood cells increased in length while living in space.

The Independent reports that telomeres, which are involved in the repair of damaged DNA, slowly gets shorter as people ages. This causes the decrease in the person's effectiveness and increases the risk of cancer.

The scientists expected that the intense radiation that the astronauts are exposed to in space could shorten their telomeres. On the other hand, Susan Bailey, a radiation biologists and focuses on telomeres and telomerase, said that it is exactly the opposite of what they thought.

According to NASA, the scientists found in the study that Scott's telomeres increased in length after spending one year in space. They associated it to an increased exercise and reduced calorie intake of Scott Kelly while in space.

On the other hand, they found that upon his return to planet Earth, the telomeres began to shorten again. Meanwhile, the telomerase activity, which is the enzyme that repairs the telomeres and lengthens them, increased in both twins in November. This may have been associated with a significant, stressful family event during that period.