Washington: 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 the United States 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, funded by NASA and presented at the 2008 American Association for Cancer Research annual meeting, shows that the high-energy radiation found in space may also lead to premature aging and prolonged oxidative stress in cells.

A 2004 report from the US National Academies suggested that cancer incidence may be higher in the astronaut population as compared to the general American population, and the US National Research Council published a report last month that recommended increased research into the radiation exposures to astronauts.

The research 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.

The researchers concluded that the cellular environment of the gastrointestinal tract was highly oxidative, or full of free radicals, for prolonged periods of time, a state which is conducive to cancer development, the Science Daily online said.

Datta and his team also found that the mice exposed to the high-LET radiation aged prematurely. Datta, the study's lead author, says the mice's coats became prematurely grey, an observation the team plans to follow-up with MRI brain scans.

Source : PTI