FOUNTAIN of youth which could help us live longer, stay younger and protect us against cancer, has been identified by scientists.

Researchers in Spain discovered a way to make mice live up to 16per cent longer - equivalent to an extra 12 years on the average human lifespan.

The elixir of long life and health is a protein called p53 - discovered in Scotland by Sir David Lane, of Dundee University.

Mice with elevated levels of p53 appeared younger, healthier and were more resistant to the development of cancers, according to a study by scientists at the Spanish National Cancer Research Centre.

Their discovery will accelerate the development of new drugs that fight cancer while extending healthy youth and lifespan. The protein p53 is known as "the guardian of the genome" because it makes sure that damaged cells destroy themselves and do not divide uncontrollably to cause tumours.

Scientists have long speculated that boosting our body's levels of p53 could help us live longer, but early studies found it actually accelerated ageing.

Now these findings have been sensationally overturned by Dr Manuel Serrano, of the Spanish National Cancer Research Centre. His team genetically engineered mice to have an extra copy of p53 and a related gene - ARF.

They showed that mice with an increased dose of the two proteins were more resistant tothe development of cancers. It came as no surprise, therefore, that these animals had an extended lifespan compared with normal mice.

But remarkably, the animals outlived their normal counterparts even after the impact of having less cancer was removed from the equation.

Moreover, various biological and molecular markers of ageing indicated that these mice stay younger for longer. The researchers conclude that boosting the body's ARF/p53 activity provides an anti- oxidant effect, which not only suppresses cancers, but also delays ageing.

"The mice lived 16per cent longer in their average lifespan, " said Dr Serrano, whose findings were published yesterday in the journal Nature.

"Everyone agrees that ageing is produced by the accumulation of damaged cells. If p53 is the main quality control that eliminates such cells, then the expectation is that having more p53 mice will have a more strict quality control for cells, hence less cancer and less ageing."

The study opens up possibilities for new drugs that delay ageing by boosting the body's production of p53.

"There are a number of chemical compounds that have been developed by the big pharmaceutical companies and these compounds are able to boost p53 in the organism, " said Dr Serrano.

"These compounds are being tested now for their possible anti- cancer activity and hopefully in the light of our study also for their possible anti-ageing activity."