IN case you missed it, here is the good news. A drug has been developed which appears to slow down the process of ageing. But before you cancel your advance order for a Zimmer frame, here is the bad news. So far it has only been tried out on primitive worms.

The widespread publicity given to last week's discovery by scientists that a drug which gets rid of substances called oxygen-free radicals could allow nematode worms to live up to twice as long as usual, shows that the old dream of an elixir of youth is still very much alive.

But Professor Tom Kirkwood, an international expert in the study of ageing, would like to see a more realistic view of the future.

"The result is important but we have to recognise that there is a big contrast between humans and nematode worms," says the professor, who is based at the pioneering Institute for the Health of the Elderly in Newcastle. "Once the adult worm is formed, the cells will never divide again, which is very different to people. This result will not necessarily carry across to human beings where there is a much larger variety of cell types."

So far the record for longevity is held by Frenchwoman Jeanne Calment, who died in 1997, aged 122. An American woman, Sarah Clark Knauss, is coming up to her 120th birthday later this month. And most of us can now expect to reach 75 - an incredible improvement on the 40 years one could expect in the 1400s.

But with so many elderly people spending their twilight years suffering from illness and disability, the great challenge is to improve what the experts call "healthspan" rather than lifespan, by finding ways of reducing illness.

Despite his caution over last week's breakthrough, Prof Kirkwood believes we are entering an era when our knowledge of the process of ageing will be transformed - aided by high-tech equipment such as a system which uses lasers for micro-dissection of individual human cells which will soon be installed at the Newcastle centre.

"People have this fascination with the idea that there is an elixir to be discovered. In some ways it is unfortunate that research into the ageing process tends to get hi-jacked by this obsession. We all have to age and in the forseeable future we will all experience the ageing process. Rather than focusing on the possibility of eternal youth, we should be focusing our attention on the prospect of a healthier old age. That is an attainable goal," says Prof Kirkwood, who heads the department of gerontology.

Improving the health of the increasing numbers of over 85s in the UK is the challenge of the age, he says.

He believes that the 100-strong multidisciplinary team of doctors, scientists, nurses and support staff which has been gradually built up at the Newcastle Institute is uniquely placed to make the discoveries which will improve the chances of future generations of elderly people enjoying their seventies, eighties and nineties in good health.

If the spin-off of better advice on how we live our lives is a longer life-span, then that will be a bonus, he says.

"This is a very exciting time in ageing research and the set-up here in Newcastle is unique. We have enough critical mass of expertise across many different fields to be able to take a concept and follow it through from research to how it can be applied to a patient," he says.

Since it was set up in 1994 - building on a history of excellence at Newcastle General Hospital which dates back to discoveries about the nature of Alzheimer's Disease in the 1960s - the Institute has steadily grown.

Thanks to millions of pounds from the Medical Research Council, the National Health Service, Newcastle University and the Wolfson charity, it is now among the international big-hitters in the growing field of research into ageing.

The centre has been the vision of Professor Jim Edwardson, the Institute's director. From South Shields, Prof Edwardson takes great pleasure in the fact that the Tyneside centre is now attracting applications from high-flying scientists from Oxford and Cambridge universities and even further afield.

A measure of the centre's growing international stature is the recent arrival of two biogerontologists from universities in Germany. Professor Kirkwood, originally from Manchester University heads the team which is trying to find out why we age and why aged cells and tissue become more vulnerable to disease.

Prof Kirkwood says there is now wide agreement on the factors that contribute to ageing - particularly the role of oxygen-free radicals and structures at the end of chromosomes known as telomeres, which play a role in how long cells continue to divide.

"We now have the ability to look at the processes which damage DNA as we get older. In ageing, we know that the brain begins to run down but some cells are more severely affected than others. To understand how this works you need to to look at individual cells," he says.

The combination of the latest technology with the ability to follow patients through all the stages of brain disease, such as dementia and Alzheimer's, gives Newcastle an edge over many international competitors. A greater understanding of brain disease is vital to reducing the severe illness and disability experienced by the elderly.

At a recent international conference on ageing held in Oxford, it was revealed 3.7m people are suffering from dementia in the European Union, 2.9m suffering from stroke and another one million are afflicted by Parkinson's disease.

Within the Institute, Prof Edwardson heads the joint Medical Research Council/Newcastle University Clinical Centre for Brain Ageing.

"The team I have been associated with is looking at the major causes of brain disease and disability in later life and trying to come up with new cures.

"Another group is trying to decide how we make recommendations about healthy lifestyles," says Prof Edwardson.

So far all the familiar advice about regular exercise, lots of fish, fruit and vegetables, a moderate intake of alcohol and an avoidance of smoking and saturated animal fats seem to be the best way to stave off premature ageing. But the scientists are hoping to be able to demonstrate exactly how a healthy lifestyle affects the ageing process.

There is already hard evidence that the muscle fibre of veteran athletes shows less signs of damage and ageing than that of a young "couch potato".

The recent discoveries about the Genome Project - mapping the human genetic code - is another major factor in understanding how genes influence our expectation of life.

What is an advantage is the relative stability of the population of Tyneside, which means that the Newcastle centre is ideally placed to study genetic influences on longevity and illness. "People like the area and try not to move," says Prof Edwardson. "We have now got a very successful research institute - and I wouldn't have it anywhere else."

One of the ironic things about the pioneering centre is its history. The building which is now used as a treatment and research centre catering for the elderly was once a maternity unit. A reminder to us all, that elixir of youth or not, we all have an end and a beginning.