NASA and even private companies SpaceX and Boeing look forward to bringing people to Mars, but findings of a new study revealed another health issue that astronauts and Mars colonizers could experience as they travel to the Red Planet.
Findings of a new study have showed that astronauts grow taller during long-term space flight but lose important muscle mass. While gaining some inches in height may seem to be a perk of space travel, changes to the spine are not actually a desirable thing because these often come with back pain and injuries.
Months in space could lead to muscles supporting the spine to shrink, and these do not return to normal even after a person has returned and stayed on Earth for several weeks.
For the new study, researchers from the University of California, San Diego, assessed six astronauts who stayed on the International Space Station for four to seven months. They found that the cross-sectional area of muscles that run along the spine, which helps support the spine and prevent misalignment, decreased by 19 percent after the astronauts stayed at the ISS. Only about two-third of this reduction recovered after a month or two of returning to Earth.
"Paraspinal lean muscle mass, as indicated by the functional cross-sectional area (FCSA), decreased from 86% of the total paraspinal muscle (PSM) cross-sectional area down to 72%, immediately after the mission," the researchers wrote in their study, which was published in the journal Spine.
"Recovery of 68% of the post-flight loss occurred over the next 6 weeks, still leaving a significantly lower lean muscle fractional content compared to pre-flight values."
The results showed that in microgravity, where astronauts do not rely on the spinal muscles to stabilize and support the body as they float weightlessly in space, muscles are prone to atrophy that causes the bones in the spine to straighten out and stiffen.
These body changes may help explain why many astronauts suffer from back pain after traveling to the ISS in low-Earth orbit.
Researchers used to attribute astronaut's back pain to the swelling of the spinal discs when the back is not compressed by the weight of the body, but MRI scans of the astronauts did not show evidence of this.
"These findings run counter to the current scientific thinking about the effects of microgravity on disc swelling," said study researcher Douglas Chang.
Researchers said the findings mean that astronauts may have to make changes to their routines in space so they can stay healthy. Astronauts, for instance, may have to perform core-strengthening exercises and neck exercises so they can keep their back healthy.
The results likewise suggest it is crucial to address this particular health problem as NASA plans to send a manned mission to planet Mars in the future.