Revealed: the secret of immortality
Scientists have identified DNA strands that could hold the answers to switching off the ageing process.
If fancy cars or free holidays don't excite you, a competition run online offered what can only be described as an unusual prize to one 'lucky' winner.
The Live Forever campaign, run by a consortium of 140 charities in the UK, gave applicants the chance to be frozen to -196°C after death, in case science one day found a way to bring them back to life. It was a clever idea, as anyone who was curious about immortality and visited the website was reminded that there was another way of ensuring the things you care about live forever - by bequeathing a gift to charity in your will.
Unless you win a prize like this, the prospect of being cryogenically frozen is a costly one. Membership of the Cryonics Institute in Michigan, US, costs around $30,000. Despite this, there is demand. Over 100 bodies currently lie preserved in liquid nitrogen at the facility, which offers clients the "prospect of immortality". More potential patients are registering their interest all the time.
If you fancy the chance of living forever, but can't stand the cold, science is working on a solution. Much of the current excitement about halting - or even reversing - the ageing process involves something all of us have, but might never have heard of: telomeres.
Not dissimilar to the tabs on the end of our shoelaces, telomeres are little stretches of DNA on the end of our chromosomes, which stop them from unravelling.
"Telomeres hold the key as to why we age," explains Dr David Barton, chief scientist at the National Centre for Medical Genetics in Dublin.
"Our body is made up of cells, and every cell has 23 pairs of chromosomes. Each time our cells divide, the telomeres on the end of our chromosomes get shorter and shorter. Eventually, they are too short to be functional and the cell dies."
Andrew Green, Professor of Medical Genetics at UCD, offers another theory. "It may be that shorter telomeres are just a sign of ageing - no more than wrinkles or grey hair - rather than a cause," he says. "There's a suggestion that if you can restore telomeres, you can reverse some of the signs of ageing. But even if you could do this, you're not sorting out the underlying cause of ageing. We still don't know what this is."
Either way, it's not in doubt that as cells die, we age. So surely, if they're so crucial to keeping our cells alive, all science has to do to halt the ageing process is to find a way of preserving our telomeres?
That's where something else we may never have heard of could play a part. "Telomerase is an enzyme which allows our telomeres to be repaired," explains David Barton. "But it's mainly inactive in normal cells."
Unfortunately, it's often 'switched on' in something we could do without.
"Telomerase allows cancer cells to survive. Without it, they would divide a certain number of times and then die, and cancer wouldn't be a problem," David says.
So, surely tackling cancer and halting the ageing process should be as easy as finding a way to turn off telomerase in cancer cells and turn it on in normal cells, to protect their telomeres?
"There's lots of research going on in this area," says David, "but clinical trials generally haven't lived up to expectations. Cancer, in particular, is pretty complex. When you think you have a simple explanation, it usually turns out not to be the answer.
"There hasn't been much success in trying to switch on telomerase in ordinary cells and find the elixir of youth either," he continues.
"If there had been a breakthrough, it would have been on the front page of every newspaper. But it's definitely a hot area of research and it's something that holds promise."
Telomerase is still a bit of a mystery, but maybe there's another way of controlling our telomeres, which may improve our lifespans.
Studies have found a link between longer telomeres and longer lives. David Barton says there's an obvious reason for this. "It's known that the usual healthy lifestyle options, like exercise, eating lots of fruit and veg, and not smoking seem to contribute to longer telomeres, which essentially make your cells look younger."
A whole industry has grown up around measuring people's telomeres and offering them suggestions about how to lengthen them, but David is very sceptical.
"All of these companies operate on the internet," he says. "You send off a specimen like spitting into a tube. Your DNA is tested, but mostly the advice you get is the same as what your GP would tell you - eat more fruit and veg, get more exercise, and so on. From a medical prediction point of view, there's very little value in these tests. Don't waste your money."
Telomeres aren't the only show in town when it comes to offering clues to a longer life.
"There's quite a lot of research going on into this," says Professor Andrew Green. "Scientists are studying groups of people from different parts of the world who have great longevity. There's a population in northern Italy, for example, that lives into their 90s and 100s and are well with it.
"Scientists are trying to find out what it is about their genes or their environment that means these people live longer and reasonably well. But these studies haven't yielded any concrete results yet," he says.
It's clear telomeres may have many more secrets to reveal yet, and research into these little stretches of DNA is continuing.
If a breakthrough is made, and one day immortality is achieved, it does throw up many ethical questions. Would only the rich be able to afford the magic medicine? And how would a world already struggling with overpopulation cope?
"Scientists are very conscious of the questions their work may raise, but it doesn't necessarily deter them," says Prof Green.
Dr Barton agrees: "Scientists, in general, don't believe that knowledge in itself can be dangerous. It's the application of that knowledge. That's where society steps in. Take human cloning, for example. The knowledge is probably there, but it's not permitted because society has said 'no, we don't want you to do that'."
David offers a warning: "Humans have evolved over four billion years, and if you start messing around with some of the fundamental processes that keep us alive, then that tends to turn up unexpected consequences. If we could just stay alive forever, and that was a good thing, then we probably wouldn't have evolved to die at the age we do."
A sensible thought, perhaps, but given society's obsession with finding the fountain of youth, research into telomeres - or anything else which could provide the key - is likely to continue.
Top tips to achieve a longer life
If you can't wait for telomere research to yield a breakthrough, here are some other suggestions which may lead to a longer life.
Sleep, but not too much
Studies have shown that getting less than six hours, or more than eight hours, of sleep can shorten your lifespan. Somewhere between seven and eight hours is ideal.
Bacteria can live in your teeth, and may find their way into your arteries and cause plaque. It's also possible that your body will mount a defence bacteria in your mouth, resulting in inflammation, which may in turn cause your arteries to narrow. This is bad news for your heart's health. Experts recommend daily flossing.
People who hold bitterness and anger have higher levels of stress and shorter lives.
Look on the bright side
Optimists tend to be healthier. They also tend to live longer as they can cope better with life's hardships.
Get an Education.
Studies have shown that people who stay in school and go to college live longer. In fact, it's almost as effective as exercising and eating healthily.