The secret of extending life by decades may lie in switching off certain genes, scientists believe, after showing that small genetic tweaks can make organisms live 60 per cent longer.

Ten years of research by the Buck Institute for Research on Ageing and the University of Washington has identified 238 genes that, when silenced, increase the lifespan of yeast cells.

Many of the genes are present in mammals, including humans, suggesting that switching them off could dramatically increase lifespan.

“This study looks at aging in the context of the whole genome and gives us a more complete picture of what aging is,” said lead author Dr Brian Kennedy.

"Almost half of the genes we found that affect aging are conserved in mammals.