Scientists have found a way to reverse the ageing process, extending the lifespan of mice by 20 per cent and raising the prospect of an anti-ageing treatment for humans within a decade.

The discovery has attracted the attention of NASA, which is keen to protect its Mars mission astronauts from accelerated ageing caused by exposure to cosmic radiation when they travel to the red planet in the 2030s.

David Sinclair, of the University of New South Wales and Harvard Medical School, said it was the closest scientists had come to developing a safe and effective anti-ageing drug, potentially as early as 2020.

"The cells of the old mice [in the study] were indistinguishable from the young mice after just one week of treatment," said Professor Sinclair, lead author of the research paper, outlining the findings in the journal Science.