Congratulations. Yesterday your life expectancy increased by five hours. It did again today. And it will tomorrow too, and the day after.
An Ancient Roman man counted himself lucky if he lived to 23, but a modern British male can expect to live to 75, and the figure is increasing all the time as modern technology not only cures illness but provides the prospect of anti-ageing therapies that some analysts believe could extend the average lifespan well beyond 100 within 50 years. British researchers announced this week that they had found further clues to the ageing process, with the discovery that high stress in lower socioeconomic groups seems to age them more quickly.
But while headlines trumpet about modern-day Methusalahs, philosophers, sociologists, anthropologists and the public are beginning to ask a vital question that the scientists may have forgotten: are we getting so carried away with the possibility of extended life that we’re forgetting to ask whether we want it? The leading medical charity the Wellcome Trust takes the bull by the horns next week with a debate on whether science has looked at all the angles when it comes to living a full, long life. Speakers will examine the implications on lifespan of, for example, stem-cell technology for rebuilding damaged organs and our growing understanding of the molecular and cellular processes that lead to age-related disease.
According to Dr Ken Arnold, who organised the event for Wellcome, it’s not just a matter of balancing quality of life against years lived. There are also cultural, psychological and social issues raised by extending life. Some commentators, for example, have speculated that our personalities are bound to change at least once as we develop and adapt over a period of up to 150 years.
“So much of what human beings do in art and religion, for example, is done with a view to their personal demise,” says Dr Arnold, who heads Wellcome’s public programmes department and lectures on the relationship between arts and sciences. “There is a sort of curvature to life, with things opening up and closing down at different stages, and it’s important, if some of those certainties are likely to change, that we ask philosophers, psychologists and anthropologists about the implications. The questions are too big to leave to scientists alone.”
For example, our increasing medical ability to delay the point of death leaves us the fraught decision about when it is the right time to die. John Harris, professor of bioethics at Manchester University, points out that as people are given treatment for increasingly repairable organ malfunctions, medical staff and patients will have to make decisions about whether to accept or postpone death. The dilemmas that doctors already face about whether “quality of life” is sufficient will become more complex.
“Our instinct is to preserve life and postpone death wherever possible,” said Professor Harris recently. “It will therefore be difficult for society to decide which condition and what age is deemed to herald the end of an individual’s life.” Even if it is inevitable that science will extend human life expectancy, he says, it is vital that we ask whether it is the right thing.
His comments raise the question of why we are extending human life in the first place. The answer is simple, according to one contributor to next week’s Wellcome debate, who has little time for those who believe that our obsession with longevity is simply narcissistic. Life is simply always preferable to death, according to the philosopher Nick Bostrom, the director of the Oxford Future of Humanity Institute. And by providing more time for the things that make it worth living — spending more time with our loved ones, learning new skills — we assert our humanity.
He is confident that the most promising technologies for enabling us to live longer are those that will do so by making us healthier for longer, so that we will be able to enjoy longer life to the full. “Several research areas are being explored that target the components of ageing,” he says. “One is stem-cell research, which has the potential to replenish lost neurones in the brain, repair damaged heart muscle and re-grow organs. The other is calorie restriction.” Research in animals has shown that lifespan is extended significantly by limiting the number of calories they consume, a finding that could help scientists to unlock human ageing mechanisms.
All the objections to extending human life, he says, work on the assumption that our current lifespan is natural. But human society might work better if people lived longer. “We spend 20 years raising a child, then we have a couple of productive decades, and then we degenerate. It’s not an effective set-up, if you think about it.”
That kind of optimism is all very well, say the opponents of anti-ageing medicine, but it fails to look at some of the practicalities. For example, what about the inevitable fact that the rich will have greater access to life-prolonging therapies and the poor will still die young? What about the psychological and social effect on nations suddenly deprived of the incentive to make the most of the time we have? And will the voice of the individual about when and how he or she dies become increasingly hard to hear as medical processes and procedures increasingly work on the assumption that life can be saved? The organisation Dignity in Dying says it is alarmed by the number of people contacting it with tales of life being extended by doctors against the wishes of the patient, and there is the potential for this to get worse if medics take a blinkered approach.
“There’s often a gulf between what the doctors and scientists would want for themselves, and what they are interested in in their scientific endeavours,” says Deborah Annetts, Dignity’s chief executive. “I know scientists specialising in motor neurone disease who talk about non-compliant patients. In other words, they won’t submit to procedures the doctors keep trying to administer that will extend their lives. But the same doctors will say that if they had motor neurone disease, they would want help to die.”
Perhaps the most realistic way forward comes from Professor Tom Kirkwood, the director of the Institute for Ageing and Health. Human beings are quite capable of adapting to living longer lives biologically, he says; the problems lie in a society unable to adapt to the needs of older people to ensure that those years are well spent.
“We have to bear in mind that science is telling us that we aren’t programmed to age; we are programmed for survival,” he says. “In the Stone Ages, mankind survived by being able to sexually replace itself, rather than by maturing and growing. The fact that in these less dangerous times we don’t have better mechanisms to maintain health over a long period is a hangover of that. But new data is revealing that age is malleable and that if we make the right decisions in life, it is possible to reach old age in good shape.”
Predictions of human beings extending life indefinitely are science fiction, he says. Stem cell experts say that regenerating tissues with stem cells hasn’t even been proved to work yet, never mind extending life expectancy. But if we work from more conservative projections, that life expectancy is conservatively rising by two years every decade, the question of whether we want to extend life becomes a little less frightening.
Perhaps what we need to grapple with is not how long we want to live, but how to ensure that our extra years are healthy and well spent. Professor Kirkwood believes this represents a greater challenge even than climate change.
“It’s a fantastic thing that we’re living longer,” he says. “But we’ve still failed to address how we keep people in good shape once they get there. The damage that accumulates and makes us unwell in old age has often begun in the womb, so if we want to be healthy longer, we need to make efforts throughout our lives.”
For details of Wellcome Trust events, visit www.wellcomecollection.org , 020-7611 8888, or e-mail events@wellcome.ac.uk
Sticking around
The reason we are living longer is because we are only becoming dangerously ill, with conditions such as cancer and heart disease, later in life.
