(Newser)
– They called it the “perfect nature versus nutrition” experiment: astronaut Scott Kelly was sent to the International Space Station for nearly a year, while his identical twin, astronaut and now Senator Mark Kelly, remained on Earth. When Scott Kelly returned home in March 2016, scientists compared his DNA and body makeup to that of his twin and found that Scott was 2 inches taller than him and had lower body mass, among other changes ( most of which have been reversed). Now, according to a study published Monday in the journal Circulation, announced another major change: Kelly’s heart mass dropped during her cosmos traveling from 6.7 ounces to 4.9 ounces, or about 27%, though the astronaut did not appear to suffer any repercussions important because of this. “He did remarkably well over the course of a year,” explains study co-author Benjamin D. Levine, a professor of internal medicine at Southwestern Medical Center at the University of Texas. New York News.
CNN Teller: When humans deal with the gravity of the Earth, the heart has to work harder to pump blood. In zero gravity, however, the heart does not have to work as much and therefore atrophies. Levine tells him to Time that Kelly’s heart did it without becoming “dysfunctional”. The study also examined Benoit Lecomte, a resistance swimmer who tried to cross the Pacific in 2018. The buoyancy of the water and the almost constant horizontal state of Lecomte during his five more months of swimming produced conditions similar to Kelly’s weightlessness, and her heart shrank almost as fast. While Kelly finished well, she also did a lot of exercise while in space with exercise equipment, probably keeping her heart from weakening even further. Scientists are concerned that astronauts on future missions may be prevented from exercising due to injury, illness or equipment breakdown and suffer more serious effects. NASA is funding more research on the heart involving astronauts on both long and short-haul trips. (Read more discovery stories.)