The race for space tourism may be heating up, and space agencies around the world dream of sending a man to Mars, but the practicality of intergalactic may have hit a snag. Adding to the growing list of health risks involved with space travel, new research suggests that it may be harmful for the brain because galactic cosmic radiation could cause Alzheimer's disease.
The planet and people in low earth orbit are generally protected from these cosmic radiations by the earth's magnetic field, however, once astronauts leave orbit they are exposed to a constant shower of various radioactive particles.
Professor Kerry O' Banion of the University of Rochester Medical Centre Department of Neurobiology and Anatomy said:
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."
Tests conducted on mice with models of Alzheimer's showed that after being exposed to various doses of radiation, including levels comparable to what astronauts would be exposed to during a mission to Mars, the mice were much more likely to fail tasks earlier than symptoms would typically appear, which suggests neurological impairment.
Furthermore, the brains of the mice also showed signs of vascular alterations and a greater than normal accumulation of the protein "plaque" that accumulates in the brain, which is also one of the hallmarks of Alzheimer's disease.
"These findings clearly suggest that exposure to radiation in space has the potential to accelerate the development of Alzheimer's disease."
The newly discovered risk of developing Alzheimer's from space travel is yet another factor that NASA will need to take into account in the planning of future missions.
Astronauts can be shielded from some forms of radiation, but there are other forms that cannot be effectively blocked. The longer that an astronaut is in deep space, the greater the exposure.
This could prove to be a significant worry for the space agency as it is planning manned missions to a distant asteroid in 2021 and to Mars in 2035. A roundtrip to Mars could take as long as three years.
NASA has been funding research to determine possible risks of space travel for twenty five years now. Several studies have demonstrated the potential cancer, cardiovascular and musculoskeletal impact of galactic cosmic radiation. This study, however, is the first time the potential impact of space radiation on neurodegeneration and the development of Alzheimer's disease has been looked at.