Astronaut Scott Kelly spent a year in space while his twin Mark Kelly was on Earth.
Highlights
- NASA study finds space travel may have reversed aging in one astronaut
- This is contrary to the perception that one ages faster in zero gravity
- Scott Kelly, who was in space for 382 days returned younger than his twin
Does travel in space reverse ageing? Contrary to general perception that one ages faster in near zero gravity, a new NASA study finds space travel may have reversed aging at least in one astronaut.
The preliminary results released by NASA after studying the human biology of how a twin, astronaut Scott Kelly who went into space for over a year and how his sibling Mark Kelly who stayed on Earth compared, has thrown up a remarkable finding. At least on two important parameters astronaut Scott Kelly came back younger than his Earthbound sibling.
A key indicator for ageing is how the ends of the chromosomes - the small packets in a cell that carry DNA - behave. These tips are called telomeres. As one ages, the telomeres actually shrink but in the case of astronaut Scott Kelly - who spent 382 days aboard the International Space Station - his telomeres actually became longer. However, after his return to Earth they began to shrink again like his twin.
According to NASA, "Interestingly, on a time scale of just one year, (the study) found Scott's telomeres on the ends of chromosomes in his white blood cells increased in length while in space. This could be linked to increased exercise and reduced caloric intake during the mission. However, upon his return to Earth they began to shorten again. Interestingly, telomerase activity (the enzyme that repairs the telomeres and lengthens them) increased in both twins in November, which may be related to a significant, stressful family event happening around that time."
In addition, another biochemical marker that indicates ageing was lower for Scott Kelly.
NASA suggests that not much should be read into these findings and one shouldn't start queueing up for space travel. A simple fact that the twin who was in space had a low calorie diet and exercised more could be the simple answer. But more analysis is necessary.
In addition, when the entire genome of the two was sequenced more than 200,000 different changes were found between the two which is not abnormal, but NASA says they will "look closer to see if a 'space gene' could have been activated while Scott Kelly was in space."
Samir Brahmachari, well known Indian genome specialist and former director general of the Council of Scientific and Industrial Research (CSIR), New Delhi who has done work on twins and ageing said "This increase in the length of the telomere of the person who was in space is unbelievable and fantastic and it holds great promise to open up frontiers of long duration inter-planetary travel, but the exact reasons need to be investigated much more."
On the other hand, the only Indian astronaut Wing Commander Rakesh Sharma who spent eight days in space in 1984 on an Indo-Russian mission was not convinced that the NASA study was comparing apples to apples since the twin who remained on Earth, Matt Kelly, led a different lifestyle compared to his twin brother who flew in space. In addition Rakesh Sharma says "One needs to carefully analyse the exact quantum of radiation exposure the twins faced."
NASA says "These studies are far from complete. Additional research analysis is in process."