Still seeking the elixir of life? Just don't expect it at the

Death avoidance is a major industry. Less and less of us seem willing to go gently into that good night. Try Googling 'life extension' and you will get 72 million hits. Most will be quacks in California promising to double your lifespan, but there are many reputable medical research programmes working towards helping you and me make a century. Some parts of America appear to believe that death is optional. But as my colleague, the Newcastle gerontologist Tom Kirkwood, argues, the aim of ageing medicine should be to add life to years, not years to life. If we worry about the increasing global population, we should remember that this is partly as a result of our survival into older age in the developed world, as well as of the developing world having more children.

Recent gains in life expectancy are associated with increases in morbidity. In other words, people in the industrialised countries may be living longer, but for many, our final 20 years will be blighted by dementia, macular degeneration, osteoarthritis " and increasingly costly medical treatment. Rather than aiming for immortality, the goal of medical research into ageing should be what gerontologists call 'rectangularisation of the life curve'. Or in the words of one of my friend's patients, 'I want to live to 100 and then be shot by a jealous husband.' People should worry less about when they are going to die, and place more emphasis on maintaining good health for a reasonable period, followed by a rapid death, not a slow decline.

What should our aspirations be, when it comes to medicine? What are the goals of health care? According to US bioethicist Dan Callahan, we just want more, more, more of it. No wonder we never decide that we have had enough. We are operating what he calls an 'infinity model of progress'. Callahan suggests that we need a debate on the limits to medicine. By accepting finitude and agreeing on sustainable healthcare, we might be able to consider what it means to live a good life and how we can improve the quality of life for more people. The problem is not medicine itself, it is the expectations that we place on our doctors, and the role we expect health care to play in our lives.

The real news story in medicine is the persistence of health inequality. If you are a male resident of Kensington and Chelsea, you can expect to live to 80, but if you are a man living in Shettleston, Glasgow, you are likely to be dead by 63. And social differentials in both life expectancy and infant mortality are actually getting worse. A cause and consequence of this situation is that the obsession with health and medicine is particularly associated with middle-class people, who expect to have choice and control over their lives and are unfamiliar with death. In contrast, many people in working-class communities have had experience of friends and relatives dying early. Expectations of medicine are lower and values such as coping and acceptance dominate. Premature mortality is even more acute on a global scale.