A recent study has found that space radiation may cause astronauts in outer space to lose new bone, but not more muscle. The conclusions raise interesting questions about the relationship between bone and muscle, particularly for people on Earth dealing with age-related bone and muscle damage. As NASA plans for deep space travel, astronauts will also face increased, continued exposure to space radiation.
In the original study of its kind, researchers examined the combined effect of space radiation and microgravity on bone and muscle, hypothesising that radiation would worsen bone and muscle loss induced by microgravity.
Experts studied mice whose movements were restrained, an encounter similar to microgravity and those shown to simulated space radiation. What they discovered was that while microgravity alone managed to both bone and muscle loss, radiation alone did not.
“Radiation plus microgravity amplify the negative impact of microgravity on the bone, but does not affect muscle loss,” stated Henry J Donahue, Virginia Commonwealth University in the US. “It’s as if showing to radiation itself doesn’t harm bone, but it makes it more sensible to the negative effects of microgravity,” told Donahue.
While in the decreased gravity of space, astronauts lose bone and muscle from their legs, hips and lower backs. The study, published in the journal PLOS ONE, proposes that astronauts on extended space travel missions would have great bone and muscle complications.
Experts want to find how to maintain bone and muscle health during spaceflight and determine what preventive exercises could help. The loss of bone and muscle encountered by astronauts in microgravity is comparable to what happens as people age, Donahue said.
As lifespans have increased thanks to medical advances, the problem has become more prevalent. Older people fall more; they break their bones more, Donahue said.
“Understanding the relationship in microgravity between bone and muscle has significance to the effect of ageing on muscle and bone,” he concluded.