Scientists have managed to make old skin in mice young again after just two weeks of treatment by blocking a single gene, according to a study released Thursday.

They did this by creating genetically-modified mice with a defective gene that can be switched off so that their cells ceased to age when a cream was applied to the skin.

While still years from being determined safe for use in humans, the discovery offers hope of one day reversing many age-related illnesses and injuries as the technique may work on any kind of organ or tissue.

"Previous work has shown you can reverse aging by really drastic measures" such as a near-starvation diet or "connecting the circulation of a young animal to an old animal," said lead researcher Howard Chang of the Stanford University School of Medicine in California.

"Here we show that aging in mouse skin can be reversed by blocking a single gene," he said.

"These findings suggest that aging is not just a result of wear and tear, but is also the consequence of a continually active genetic program that might be blocked for improving human health."

Chang's team use a complex computer analysis to discover that a single protein is the "shared driving force for the genetic changing associated with aging in lots of different tissues," he said in a telephone interview.

They then designed a genetically-modified mouse in which this gene would switch off only when the animal was quite old.