How old can human beings really get? Discounting the ridiculous math of the Old Testament, the current human limit is about 122 years old. One old woman that lived to 110 donated her body to science so that her longevity could be studied. Researchers determined that it may be our stem cells that limit how long we could live as there are only a finite supply of them and over time, as they stop regenerating, so too do the body's repairs. They believe humans begin life with about 20,000 blood stem cells and it was found in her body, at the time of death, she was literally down to 2. The researchers found their approach unique to looking at somatic mutation (non-cancerous) and believe the discovery may imply that an injection of fresh stem cells could prolong and rejuvenate our bodies.