“We have a dozen ways to make mice live 20 percent longer than they do now,” said Stephen Austad, professor of biology at University of Alabama at Birmingham. “That’s a huge shocker. But given the number of ways that work in animals, I’m quite confident that some will extend to people. We are likely to see a quantum leap.”

Austad and colleagues are preparing to launch a clinical trial of a diabetes drug called metformin that has the side effects of keeping patients free from the diseases of aging.

“Nobody will have a trail where you give something to a bunch of 20 years olds and wait until they die,” said Austad. “What will happen is we will start using older people. The only way to demonstrate that something works like this is take a group of people at sufficient risk of death that you will be able to see a difference.”