Research with rodents suggests injury to brain from cosmic rays
TUESDAY, Oct. 11, 2016 (HealthDay News) -- President Barack Obama's declaration Tuesday to send astronauts to Mars and back by the 2030s might come with health risks to the space travelers, a new study suggests.
The study, which was done with rodents, suggests that astronauts traveling to Mars could be at risk for developing dementia because of high levels of cosmic ray exposure.
It's a condition the study authors have dubbed "space brain."
Researchers found that rodents exposed to highly energetic charged particles -- similar to galactic cosmic ray exposure faced by astronauts on lengthy space flights -- developed long-term brain damage that led to mental impairment and dementia. The effects included significant levels of brain inflammation and damage to neurons, the researchers said.
It's important to note, however, that animal studies frequently fail to produce similar results in humans.
The rodents also had lower levels of "fear extinction" -- a process in which the brain suppresses stressful associations, such as when someone who nearly drowned learns to enjoy water again.
"Deficits in fear extinction could make you prone to anxiety, which could become problematic over the course of a three-year trip to and from Mars," said study author Charles Limoli. He's a professor of radiation oncology at the University of California, Irvine School of Medicine.
The findings are "not positive news for astronauts deployed on a two- to three-year round trip to Mars," Limoli said in a university news release.
Similar types of cognitive (thinking) problems often occur in brain cancer patients who have received high-dose, photon-based radiation treatments, he said.
Limoli's work is part of NASA's Human Research Program. Research into space radiation, learning how it might affect astronauts and coming up with potential ways to offset the risks are "critical to further human exploration of space, and NASA needs to consider these risks as it plans for missions to Mars and beyond," the release said.
"The space environment poses unique hazards to astronauts," Limoli said. "Exposure to these particles can lead to a range of potential central nervous system complications that can occur during and persist long after actual space travel -- such as various performance decrements, memory deficits, anxiety, depression and impaired decision-making."
Possible solutions might include designing spacecraft with areas that have increased shielding, such as those used for rest and sleep. Even so, "there is really no escaping" the cosmic rays on a spaceship, the researchers added.
Another potential option would be development of drugs to prevent brain damage from cosmic rays, the researchers said.
The study results were published Oct. 10 in the journal Scientific Reports.
Obama, writing in an opinion piece for CNN's website, said: "The next step is to reach beyond the bounds of Earth's orbit. I'm excited to announce that we are working with our commercial partners to build new habitats that can sustain and transport astronauts on long-duration missions in deep space. These missions will teach us how humans can live far from Earth -- something we'll need for the long journey to Mars."
NASA has more about going to Mars.