Deep-Space Could Seriously Damage Astronaut GI Tracts, a New Study Finds

By Chelsea Gohd | October 1, 2018 4:30 pm
astronaut deep space health mars

Radiation could harm the intestinal tracts of future astronauts traveling to deep space. (Credit: By Gorodenkoff/shutterstock)

Traveling to and exploring space is an obviously dangerous venture. Astronauts launch with the full knowledge that they may not return, and future missions that stretch farther out into the solar system will be even riskier. Deep-space travel could even cause significant gastrointestinal (GI) damage to astronauts, according to one new study.

Researchers at Georgetown University Medical Center (GUMC) have exposed mice to radiation to simulate how galactic cosmic radiation (GCR) in deep-space will affect future astronauts. Their results suggest that the radiation could cause serious GI damage. Their study even raises concerns about how this radiation could possibly cause stomach and colon tumor growth.

“Space radiation is different from radiation on Earth,” says Kamal Datta, an associate professor in the Department of Biochemistry and a project leader of the NASA Specialized Center of Research (NSCOR) at GUMC. Currently, “what we don’t know is how space radiation affects the gastrointestinal tract,” Datta adds. And overall, he says our understanding of how cosmic radiation affects  astronaut health is “unknown territory.”

Astronaut Guts

Every three to five days, the top layer of cells in our GI tract is replaced with brand new cells. This process is part of healthy GI function. When this replacement process is disturbed, it can change how we absorb nutrients and even lead to cancer, according to Albert Fornace Jr., co-author of the study and director of the NASA Specialized Center of Research (NSCOR) at GUMC.

To simulate the deep-space radiation astronauts might experience, researchers exposed mice to short bursts of a low dose of ionizing radiation at the Nasa Space Radiation Laboratory (NSRL). Researchers compared these mice to mice exposed to gamma rays, which are comparable to X-rays, according to a statement. Alongside a third, control group, researchers monitored the mice following exposure and found that mice in the radiation group, or the mice exposed to radiation comparable to what astronauts might experience, formed cancerous growths and weren’t able to absorb nutrients properly.

Additionally, the research team found that the mice exposed to radiation produced more senescent cells, which are a type of cell incapable of regular cell division. These cells can slow down the replacement of GI cells, therefore slowing down GI function, cause oxidative stress and even cause serious GI damage.

This harm caused by the radiation appeared to be permanent, according to the statement.

Risks to Astronauts

The team says they plan to continue studying these effects in mice and will use longer bursts of radiation to simulate longer exposure. And while “mouse data” might not be a perfect analog for studying impacts to human health, there aren’t enough astronauts to collect data from to form a conclusion with and there would likely be ethical issues if researchers tried to use human astronauts as test subjects in a similar experiment. Nevertheless, Datta hopes to develop a risk estimation model for humans that would let space agencies calculate the risks to astronauts on future missions.

Once they understand the risk better, Datta said, “the goal is to develop protection measures whether we can test some drug or medicine that can prevent all the changes we observe.”

This work was published Oct. 1, 2018, in the Proceedings of the National Academy of Sciences (PNAS).

Editor’s Note: This story has been updated to clarify language. An earlier version of this story referred to “iron radiation.” The particles being studied are charged iron nuclei that reach our solar system from deep space.

CATEGORIZED UNDER: Space & Physics, top posts
  • Chuck Pro

    What, exactly, is iron radiation? Perhaps the author meant ion radiation?

    This is becoming an epidemic. Last evening we had the writer that used the terms dark energy and dark matter interchangeably. With the money crunch happening in the news business I can understand a new J school grad getting tasked with writing about something they don’t understand and making mistakes. I don’t understand it getting past editors. I’m not one and I caught it at a glance.

    No wonder no-one believes the news.

    • Michael Cleveland

      I have been complaining for years about the replacement of educated journalists by illiterate–but far less expensive–bloggers, those would-be journalists who don’t want to be bothered with doing the classroom time. Journalistic standards have gone the way of the Dodo. Expect it to get worse.

      • Chuck Pro

        It’s inevitable. The era of news curated by a trusted person or organization was pretty short. It ended at least a decade before anyone noticed it seems.

    • polijunkie100

      It is possible they are talking about ion. It is also possible they are talking about ionized iron nuclei. ‘Cosmic’ radiation comes from supernova explosions that are also responsible for creating all the heavy elements.

      • Michael Cleveland

        The more likely by far is ionizing radiation, which is dangerous and far more prevalent.

      • Chuck Pro

        Do you think that’s what was meant?

  • Uncle Al

    The singular valuable ISS FUBAR experiment would load a colony of wild small voles with three to six months lifespan. Three weeks gestation, sexual maturity in a month. Conservatively cycle six generations/year. ISS FUBAR (the Concorde of space) has been burning money for 20 years, minimum 120 vole generations or 3300 human generation-years

    We could known about mammal evolution to micro-gee and chronic low level hard radiation exposure. Instead, we know nothing. NASA – guaranteed zero-risk high cost nothing.

    • Michael Cleveland

      One aspect of this that no one (to my knowledge) has addressed is the Doppler effect. If we achieve the significant percentage of light speed that would be necessary for interstellar travel, any energy arriving from in front of the ship would not only be dopplered to a higher energy but increase yet again by time dilation. Add radiation generated by impact with the occasional partial of interstellar dust and the whole thing takes an impractical turn.

      • Herodotus

        I quite understand your equivalency of voles and time dilatation, well put.


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