Astronauts may be at increased risk of premature aging due to exposure to radiation found in space, suggests a study that could have major implications for long-duration space travel. The findings from the Lombardi Comprehensive Cancer Centre at Georgetown University Medical Centre in US shows that astronauts may be at increased risk of colon cancer due to exposure to the high linear energy transfer (LET) radiation found in space. The study shows that the high-energy radiation found in space may also lead to premature aging and prolonged oxidative stress in cells. The US National Research Council published a report that recommended increased research into the radiation exposures to astronauts. The team led by Kamal Datta, assistant professor at Lombardi, measured the level of free radicals present as well as the expression of stress response genes in the cells of mice exposed to high-LET radiation similar to that found in space. They concluded that the cellular environment of the gastrointestinal tract was full of free radicals for prolonged periods of time, a state which is conducive to cancer development. PTI