That by 2050 ,scientist believe that due high technology and emerging of robots ,humans will live an work less or stress free life reducing death cause by 16% , which is good . Their is an that in the future there might a chance that there is no pollution or very less pollution because of awareness of environment or development of Eco-friendly vehicles . So,there is a lots and lots of chance of you being a centenarian, so be healthy,live long
As technology advances, it is almost definite that breakthroughs in the medical science is happening everyday. Like you have said, stemcell research may be carrying out in the not long future and that with the current development like nanotechnology, there may be other alternatives to improve treatment of health. Therefore, it is more likely that life in 2050 is lengthened.
It's no question that modern medicine has been keeping people healthier and alive, but even modern medicine can't top heredity. We have medicine that keeps elders alive but to what cost? Many are locked up in a nursing home having to inject/swallow medicine every day just to stay alive while others are 90-100 years old and still go for long walks. For the latter happen to be the case for everyone, I would imagine we'd need to invest in stemcell research, which we're not, so we have a long, long way to go.