Here is a recent research on stem cells and aging. It was tested in mice only not humans.
http://www.montrealgazette.com/news/canada-in-afghanistan/Stem+cell+injections+slow+aging+mice+study/5942956/story.html
http://www.montrealgazette.com/news/canada-in-afghanistan/Stem+cell+injections+slow+aging+mice+study/5942956/story.html