Image result for increasing human lifespanIncreasing human lifespan risks turning huge numbers of people into walking zombies because experts are not close to solving the problem of dementia and brain cell loss, a leading scientist has warned.

Labs across the world are trying to tackle the causes of ageing, and have recently made important breakthroughs in understanding why cells grow old and die, and how to stop the process.

Likewise improvements in treating diseases like cancer, and advances in vaccination and nutrition, mean populations are living longer than ever.

The oldest person to have ever lived, Jeanne Calment, died at the age of 122, and scientists now think that 120 is around the maximum age humans could live to, unless they…