Catherine Salmond: Live longer by finding out what will kill you

IT'S the stuff of science fiction which could frighteningly soon become everyday reality. Just imagine visiting your GP, getting your mouth swabbed and waiting a few hours – then being told what the state of your health is likely to be for the rest of your days.

Picture yourself sitting there, looking at a medical report charting your chances of succumbing to cancer or a heart attack, or developing any number of debilitating conditions, many of which you've probably never heard of, never mind considered the chances of getting.

On the list there may even be warnings about the chances of your children – who may not yet be born – inheriting a life-limiting illness.

And, even if you're healthy, there will certainly be heavy clues to that dreaded question, "Have I got long to live?"

It is all, of course, a matter of decoding your DNA.

Today, scientists at Edinburgh University revealed they have found a way to extract the vital clues quickly – and at relatively little cost – through a new form of DNA testing.

By studying the unique coding in each of our DNA, they will be able to inform us almost instantly of our risk of developing any number of diseases.

The idea of testing individuals for certain diseases is no longer revolutionary.

The great breakthrough achieved by the Edinburgh University team is devising a quicker and cheaper method, which promises to produce results within as little as 30 minutes for some conditions.

But most radically it offers the option of a complete genome test – potentially unlocking a comprehensive individual health map – within just a few hours and for around only 600-700 per person.

Their trick – for the benefit of the scientists among us – is using chemical analysis as opposed to the enzyme methods traditionally used in such tests.

For the first time, these "fast, accurate and affordable" tests bring the possibility of offering universal checks within touching distance.

The potential benefits are startlingly obvious – early detection could stop some conditions in their tracks, prevent premature deaths and potentially improve the lives of unborn children.

"This is a major step for people's health and for their children's health," explains Dr Juan Diaz-Mochon, who has led the research at the university's school of chemistry over the last 14 months.

"We're not looking to make money from this, but instead help people."

The potential impact on someone who, for instance, finds they have a genetic disposition to heart disease could be literally life-saving.

Discovering the risk early could be critical, allowing patients to change their lifestyle and dramatically reduce their risks, says Fotini Rozakeas, a cardiac nurse with the British Heart Foundation.

The patient may be much more willing to take on the advice "that you don't smoke, keep your weight down, do regular physical activity and eat a healthy, balanced diet".

But while the medical implications are as obvious as they are dramatic, concerns are already being raised about the potential psychological effects.

Is the potential trauma of discovering you carry a fairly low risk – but still a very real one – of developing a particularly nasty condition something you really want to know?

There is a clear argument that the more you tell someone the more empowered they are to improve their health and make sensible decisions about their lives.

But is there a risk of having too much knowledge? Are there circumstances when many of us would be better off protected from the truth?

Dr Chris Boyd, a senior research fellow in medical genetics at Edinburgh University, warns that caution will be needed as we apply the great knowledge which his colleagues' work offers to us.

"In many cases, it is perhaps better not to know," he says. "Of course, it's a personal thing, but in some cases it's not certain that a positive result will lead to a person developing a condition. It's only a probability, so if there was only a ten per cent chance, maybe it would be better not to know, than to have that worry."

Like any other DNA test, he insists that these new ones should not be taken without thorough preparations by both the patients and health professionals involved. "No test can ever be 100 per cent perfect – people can get false positive results," he warns.

"I personally think it is necessary for people to be offered counselling before any DNA test."

Ultimately, however scary the prospect is, the work of Dr Diaz-Mochon and his colleagues in their Edinburgh labs offers each of us the chance to learn much, much more about our bodies and our futures.

It may be frightening, but it does put the ball firmly in each of our courts.

As Dr Diaz-Mochon says: "Our aim is not to upset people – they must make the choice."