a deep study of the effects of space on human bones researchers from the University of Calgary in Canada did, and they came to a terrifying conclusion: six months in orbit wears out human limbs in 10 years.
The bones “They are a living organ,” says Leigh Gabel, an exercise scientist at the University of Calgary in Canada. “They are alive and active, and they are constantly remodeling.” But without gravity, bones lose strength.
Gabel and his colleagues tracked 17 astronauts, 14 men and three women with an average age of 47, who spent four to seven months in space. The team used high-resolution peripheral quantitative computed tomography, or HR-pQCT, which can measure 3-D bone microarchitecture at scales of 61 microns, finer than the thickness of a human hair, to image the bone structure of the tibia. in the lower leg and the radius in the lower arm. The team took these images at four points in time, before spaceflight, when the astronauts returned from space, and then six months and a year later, and used them to calculate bone strength and density.
Those astronauts in space the longest had permanent bone loss in their tibiae equivalent to a decade of aging.
“With longer spaceflights, we can expect more bone loss and probably more trouble with recovery,” says physiologist Laurence Vico of the University of Saint-Étienne in France, who was not part of the study.