According to The Telegraph:
Using a new technique which takes adult cells back to their embryonic form, US researchers at the Salk Institute in California, showed it was possible to reverse ageing in mice, allowing the animals to not only look younger, but live for 30 per cent longer.
The technique involves stimulating four genes which are particularly active during development in the womb. It was also found to work to turn the clock back on human skin cells in the lab, making them look and behave younger.
Scientists hope to eventually create a drug which can mimic the effect of the found genes which could be taken to slow down, and even reverse the ageing process. They say it will take around 10 years to get to human trials.