The proverbial fountain of youth could be in the form of drugs, after all.

The first drugs for a slower aging process could exist within five to 10 years, after which people could eventually live up to 150 years old or older, researchers say.

Peter Smith, dean of medicine at the University of NSW, said a child born today in Australia can possibly live up to 100 considering advances in medical research, improving lifestyle and public health, the Sydney Morning Herald reported.

''I think there is real hope we can extend human life by some decades further,'' Professor Smith said, adding it would be "great" to age to up to 150 if a person is well and healthy at such an age.

''The aim is not just to eke out extra existence, but to facilitate a longer healthy life,'' he said.

Smith also considered new drugs for body repair were being developed in parallel with the ongoing studies on stem cell therapies.

''People aren't going to want to retire at 65 and spend many, many decades sitting at home,'' Dr. Smith said.

Meanwhile, Baroness Susan Greenfield, a neuroscientist at Oxford University, also foresees a trend in life span improvement, such that people would start second careers at 65 in knowledge-based jobs.

But Dr. Greenfield said medical researchers have to prioritize studies in prevention and cure for dementia, which includes Alzheimer's disease.

''Otherwise the social and economic implications could potentially be catastrophic,'' she said.

David Sinclair, an Australian expert in ageing at Harvard University, said a network of genes controlled the pace of ageing, which is related to how the human body repairs itself.

Professor Sinclair has shown that resveratrol, a plant compound found in red wine, can extend the lifespan of yeast, worms, fruit flies and fat mice, by activating proteins called sirtuins. The company he co-founded was bought by GlaxoSmithKline for $US720 million in 2008.

Meanwhile, British scientists last month challenged the link between sirtuins and life span of worms and fruit flies in the journal Nature, concluding they had ''nothing to do with extending life.''

Today, clinical trials of synthetic molecules 1000 times more powerful than resveratrol were under way in people with diseases of ageing, such as diabetes 2, Prof. Sinclair noted, adding that the early trials are showing early signs of positive effects.

With these clinical trials, the top concern is treating elderly sick people. Delaying the onset of diseases of ageing comes as incidental findings for further studies later on.