The pumping of young blood into old veins could keep people sprightly as they age, says a US scientist who is visiting Australia.

"Improvements have been shown in many tissues. In muscle, the spinal cord, the liver and the brain," says Dr Saul Villeda of the University of California, San Francisco (UCSF).

"There is a growing body of work that shows something about young blood has a rejuvenating affect," he told an Australian Society for Medical Research conference in Victoria on Tuesday.

So far his work had been on mice and indicated young blood reversed some of the structural and functional changes that occurred during ageing.


"We physically connect an old mouse and a young mouse so two hearts are pumping the same blood."

While young blood helped old mice, old blood harmed young mice.

The next step was to attempt to rejuvenate an old mouse brain, said Dr Villeda.

The aim was not to extend life, but to improve it, he said.

"I don't want to live forever. This is about healthspan rather than lifespan.

"If we could live the same amount of time and be healthy longer, that would take a burden away from people and healthcare systems."

He said people with a genetic risk of Alzheimer's disease did not start deteriorating at 20.

"Something about the young body can fight it."


Rather than treating individual age-related diseases, there could be a way to prevent diseases from happening.

"This thinking is becoming increasingly mainstream. Studies are coming out of big institutions like Harvard, Stanford and now UCSF.

"It is a little unbelievable but it is based on years of solid work."