In the 21st century, will scientists reach the Holy Grail - will they discover the fountain of youth? Will we live forever?
Scientists are now close to understanding the biological mechanisms that make us age and make us die. A few decades ago, no-one thought we could add years to life. The maximum life-span possible for humans was believed to be a hundred or so - and all because of an immutable genetic clock.
But recently a series of startling discoveries has forced scientists to rethink their theories on ageing. They have already found some of the genes involved in delaying the ageing process in animals. Tinkering with them, geneticists have created races of super-organisms - fruit flies, for instance, that can live double their natural life-span and that die healthy and vigorous. Other laboratories have bred mice that can spontaneously regenerate parts of their bodies, constantly repairing the damage that is part of the ageing process. Controversially, some scientists are confident that their results can be extended to future generations of humans.
Through studying the rare condition of Progeria, which seems to dramatically accelerate the ageing process in children so that they age and die tragically young, scientists have gained further insights into what causes our cells to stop dividing and start to die. And some scientists have been able to briefly reverse the process in cells in a test tube. But the question remains, will this become a feasible treatment in the future?
The most promising advance being tried at the moment comes from researchers who have discovered how to take human stem cells - unique embryonic cells that never age and never die, that have the power to repair or replace any tissue in the human body - and inject this elixir into the brain of stroke victims, partially reversing their brain damage. If this treatment could be adapted, in the future it might reverse many aspects of the ageing process.
Through health care, and modern medicine, we have already made ourselves live longer than evolution dictates. The question is will any of the more extreme and futuristic areas of research give us immortality in the 21st century?
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