Expert affirms that missions like Artemis II produce bone mass loss in astronauts of up to “1.5% per month”

This situation is “very marked at the hip level,” he explained, after which he declared that accumulated losses of between 10 and 26 percent can be achieved in missions of more than six months. “Although there is recovery after returning to Earth, it is slow and not always complete: it requires between one and three years to reach previous values, and even without completely recovering bone mass in some areas,” he assured.

In this context, the SER has considered how microgravity conditions can affect astronauts and the relevance that the study of this phenomenon can have to better understand diseases such as osteoporosis and optimize its treatment in the general population, under living conditions on Earth.

Microgravity causes “an alteration in musculoskeletal health, which translates into a significant loss of both muscle and bone mass,” continued Gifre, since, in the absence of gravity, the bone loses the mechanical load necessary to maintain its density and quality. This loss of bone mass, “in turn, is associated with a decrease in bone quality,” he emphasized.

Furthermore, this process involves the release of calcium into the bloodstream, which can lead to complications such as kidney stones and even vascular calcification. “The loss of muscle and bone mass can be associated with the development of skeletal fractures,” he warned, along with other problems derived from decalcification.

Exercise and drugs

Given all this, space missions have incorporated measures such as resistance physical exercise and the use of drugs. “Exercise alone is not enough but, combined with treatments for osteoporosis, it has been shown to maintain bone quantity and quality,” this specialist has highlighted.

Beyond these consequences on astronauts, the SER has stated that these findings have a direct impact on Medicine, and that situations such as prolonged bed rest, spinal cord injuries and stroke present similar mechanisms of bone loss due to lack of load. “Studies under these conditions are those that generate the greatest scientific evidence on osteoporosis due to disuse and, subsequently, are applied to astronauts,” Gifre concluded.