Researchers were able to successfully transform cells from patients as old as 100 into stem cells virtually identical to those found in embryos.
If these can be used to grow healthy tissue which can safely be transplanted into elderly patients it could open up new avenues of treatment for the elderly.
Jean-Marc Lemaître of the University of Montpellier, who led the research, said: "This is a new paradigm for cell rejuvenation ... the age of cells is definitely not a barrier to reprogramming."
Embryonic stem cells can grow into any type of tissue in the body, and scientists hope they could one day be used to replace diseased organs with healthy, lab-grown replacements.
But their use in medicine is controversial because it involves the destruction of human embryos, albeit at a very early stage.
As an alternative scientists can use a method of taking normal cells from adults and reversing them to an unspecialised state, known as induced pluripotent stem cells (iPS), making them almost indistinguishable from embryonic stem cells.
But experts are divided over whether the technique can work efficiently in elderly patients, who have the most to gain from the potential treatments, because their cells have deteriorated further.
By adding two new ingredients, known as transcription factors, to the method of generating adult stem cells, they were able to overcome this hurdle and "reset" many of the key markers of ageing in cells.
There is a long way to go before the "proof of concept", reported in the Genes & Development journal, could be translated into treatments, the team said.
Mick Bhatia, director of the Stem Cell and Cancer Research Institute at McMaster University in Canada, said: "Some people report that the older the person, the more difficult it is to generate iPS but other labs suggest that that is not the case at all.
"I think it is certainly interesting that they are saying some of these age markers reversed and the age programming has made the cells youthful, but I think the proof comes down to showing that that does not happen normally when you make iPS, that this is something unique in an aged individual."