Researchers at Harvard University in the US and the University of New South Wales in Australia have made a discovery that could lead to a revolutionary drug that reverses ageing, improves DNA repair, and could even help NASA get its astronauts to Mars.

In a paper published in Science today, the team identifies a critical step in the molecular process that allows cells to repair damaged DNA.

Their experiments in mice suggest a treatment is possible for DNA damage from ageing and radiation. It's so promising, it has attracted the attention of NASA, which believes the treatments can help its Mars mission, as even on short missions, astronauts experience accelerated ageing from cosmic radiation.

The scientists caution that the effects of many therapeutic substances are often profoundly different in mice and humans, owing to critical differences in biology.

However, if affirmed in further animal studies and in humans, the findings can help pave the way to therapies that prevent DNA damage associated with ageing. Human trials are expected to begin within six months.

“Our results unveil a key mechanism in cellular degeneration and ageing, but beyond that, they point to a therapeutic avenue to halt and reverse age-related and radiation-induced DNA damage,” said senior author David Sinclair, professor in the Department of Genetics and Harvard Medical School and professor at the University of New South Wales.

In 2003, Dr Sinclair made a link between the anti-ageing enzyme SIRT1 and resveratrol, a naturally occurring molecule found in small quantities in red wine.

His latest research, he said, "should have an even greater impact on health and longevity."