A newly released study finds space travel increases the risk of developing Alzheimer’s, the latest study to unearth some of the risks presented to astronauts.
The eight-year long study, funded in part by NASA through the Space Radiation Laboratory at Brookhaven National Laboratory on New York’s Long Island, found that the cosmic radiation on such a mission could accelerate the onset of Alzheimer’s disease.
Senior author of the study, Professor Kerry O’Banion from the University of Rochester Medical Center (URMC) Department of Neurobiology and Anatomy said the study’s findings are definitive.
“Galactic cosmic radiation poses a significant threat to future astronauts,” said O’Banion. “The possibility that radiation exposure in space may give rise to health problems such as cancer has long been recognized.”
“…[T]his study shows for the first time that exposure to radiation levels equivalent to a mission to Mars could produce cognitive problems and speed up changes in the brain that are associated with Alzheimer’s disease,” he added. “This is yet another factor that NASA, which is clearly concerned about the health risks to its astronauts, will need to take into account as it plans future missions.”
The study is seen as a key finding for NASA. The U.S. space agency has funded a number of studies examining the effects of radiation on humans in space. NASA officials have hinted at a goal of sending humans to Mars by 2030, a mission that would test the boundaries of current technology in keeping astronauts safe from radiation exposure.
While Earth is largely shield from space radiation by our magnetic field, once astronauts leave orbit they are exposed to constant shower of various radioactive particles, including particles ejected by the sun. A trip to Mars would leave astronauts largely exposed for upwards of a year.
The study raises questions as to whether astronauts traveling to Mars — a mission that could take upwards to six months each way — would face challenges. The study focused on testing mice, exposing them to various doses of radiation, including levels comparable to what astronauts would be experience during a mission to Mars. Researchers say the mice were far more likely to fail these tasks, suggesting neurological impairment.
“It’s just another example of how the environment can influence diseases. The mice had a genetic predisposition, and you have added an environmental injury — an insult to their system. And now they show exacerbation of the disease,” O’Banion said, according to ABC News.
Several previous studies have shown the potential for increases in risk of cancer, cardiovascular, and musculoskeletal impact of galactic cosmic radiation. However, this study is the first to explore effects of radiation on the nervous system, a phenomenon known as neurodegeneration, according to the authors. NASA has funded a number of similar studies over the course of the past twenty-five years, saying it hopes to better understand the effects of radiation on humans in space.
“The possibility that radiation exposure in space may give rise to health problems such as cancer has long been recognized,” said O’Banion. “However, this study shows for the first time that exposure to radiation levels equivalent to a mission to Mars could produce cognitive problems and speed up changes in the brain that are associated with Alzheimer’s disease.”
Among the other major questions raised by this study is whether human travel to low-orbit space remains safe. A number of private companies, including Richard Branson’s Virgin Galactic and Elon Musk’s SpaceX, are already marketing trips to space. Just as there are resources available for the clinician who has a patient traveling on commercial aircraft, so are there resources and standards documents being developed for space travelers who have not undergone the extensive selection process currently reserved for professional astronauts. Still, the process remains far from complete and more studies are likely to follow.