WEDNESDAY, June 12, 2024 (HealthDay News) -- Mankind is eyeing Mars as its next grand expedition, but the human body might not be capable of dealing with such a journey, a new study warns.

It’s very likely that an astronaut’s kidneys could be permanently damaged by cosmic radiation during a years-long mission to Mars, researchers reported June 11 in the journal Nature Communications.

A round-trip to Mars would take up to three years, but the kidneys of lab mice exposed to the equivalent of 2.5 years’ worth of galactic radiation wound up with permanent damage and loss of function, the researchers said.

“If we don’t develop new ways to protect the kidneys, I’d say that while an astronaut could make it to Mars, they might need dialysis on the way back,” said lead researcher Keith Siew, with University College London's Department of Renal Medicine.

It was already known that astronauts who spend extended time in space suffer from the development of kidney stones, as well as other health problems like loss of bone mass, weakening of the heart and a decline in eyesight.

But until now, kidney stones had been thought to develop during space missions due to the bone loss that occurs with weightlessness, leading to a build-up of calcium in the astronaut’s urine.

“We know what has happened to astronauts on the relatively short space missions conducted so far, in terms of an increase in health issues such as kidney stones,” Siew said. “What we don’t know is why these issues occur, nor what is going to happen to astronauts on longer flights such as the proposed mission to Mars.”

These new studies instead found that human and animal kidneys are altered by conditions in space, with structures responsible for keeping calcium and salt in balance shrinking after less than a month in space.

The experiments included samples from more than 40 orbiting space missions involving humans and mice, as well as 11 Earthbound space simulations conducted on mice and rats in the laboratory.

Some of the simulations involved exposing mice to galactic radiation doses equivalent to 1.5-year and 2.5-year Mars missions, mimicking space flight beyond Earth’s magnetic field.

“Our study highlights the fact that if you’re planning a space mission, kidneys really matter,” said senior researcher Stephen Walsh, with the University College London Department of Renal Medicine. “You can’t protect them from galactic radiation using shielding, but as we learn more about renal biology it may be possible to develop technological or pharmaceutical measures to facilitate extended space travel.”

“Any drugs developed for astronauts may also be beneficial here on Earth, for example by enabling cancer patients’ kidneys to tolerate higher doses of radiotherapy, the kidneys being one of the limiting factors in this regard,” Walsh added in a university news release.

More information

The National Academies of Sciences, Engineering and Medicine has more about space radiation and astronaut health.

SOURCE: University College London, news release, June 11, 2024