In the latest study, published in the journal Cell, the scientists solved that problem by changing the genes of the mice first to make them resistant to the disease.

The researchers found that mice which had been created in this way had better muscle in old age, healthier skin tissue and fewer digestion problems.

"By simultaneously increasing the amounts of telomerase and the resistance to cancer we are able to delay ageing in mice and also to extend their life span by 40 per cent," said Maria A. Blasco, from the Spanish National Cancer Research Centre (CNIO), who carried out the study with colleagues from Valencia University.

"These mice get to live for as long as the eldest mice in records of the same kind.

"If we were to parallel it to humans, then it would mean reaching 120 years of age and also to start ageing much later in life."

Instead of testing on animals for human longevity we started testing humans to live saner, compassionate lives with the time we have, then perhaps our living longer would really make a difference.