Regaining The Power Of Youth

Researchers have achieved promising results with a new gene therapy which may restore muscle strength in the elderly.CBS News Correspondent John Roberts reports.

Jim Stovin's not an average 67 year old. Four days a week, he's in the gym pumping iron and fighting an uphill battle against age-related muscle loss.

"I think older muscles behave differently and it's certainly going to reach a plateau. And I'm probably pretty close to it," says Stovin.

In fact, as people age, they lose as much as a third of their muscle mass and strength. But using futuristic gene therapy in mice, University of Pennsylvania researcher Lee Sweeney found a way to turn back the clock.

"We were working on mice that were the equivalent of 80- or 90-year-old humans and they had the strength of the equivalent of a 20-year-old human," said Sweeney.

Inactivated viruses carrying a special gene are injected into the target muscle. The viruses attach to the individual cells and squirt in the gene. The gene then tells the muscles to rev up production of IGF-1, a naturally occurring hormone that builds new muscle tissue.

"Basically we stopped all the loss of muscle function in aging by a single injection," reports Sweeney.


in research, it's a long way from animals to humans, but in this experiment, scientists already have an advantage. Mouse muscle is very similar to human muscle. They already know that IGF-1 works virtually the same in humans as it does in mice.

It's not just older people who might benefit. Mice that mimic a form of muscular dystrophy are being treated to see if it might slow the disease.

But there is potential for abuse. Because it increases strength in young mice and is undetectable in blood or urine it could be the perfect performance-enhancing drug for athletes. Something Sweeney hopes won't detract from his real purpose.

"This is all about quality of life...about keeping people mobile and out of wheelchairs and hopefully you know, out of rest homes," says Sweeney.

The first human trials of the gene therapy are expected next year. And while it won't turn older Americans into super seniors, it may help them live better, longer.

Reported By John Roberts