Phil Hammond's funny old ward

"There's certainly some evidence but there's no proof." So said the varsity virology boffin on one of the plethora of BSE/JCD/mad cow/ loopy lamb debates that have graced our screens over the last fortnight. As the camera cut away to reveal the panellists' legs, you could see the professor shifting uneasily in his seat, suggesting he'd either missed out on the small boys' room or he was finding the spin of the red-brick microbiologist to his left a bit hard to take. The latter, who'd evidently had a bit of media skills training and looked as if he were wearing foundation, was painting a pretty Grim Reaperish scenario, though even he couldn't decide whether we're talking 500 or 500,000 cases of slow and painful death a year. Thus far, 10 British humans have succumbed to a variant of Jakob-Creutzfeldt disease, which has a pathological pattern not dissimilar to BSE in British cows. This is sad, but is it cause for world panic?

A cynic might argue that you're more likely to die in your car on the way back from the televised debate than from the disease itself, but the beauty of cynicism is that you can be disdainful without being rational. Unfortunately, it's harder to be rational without numbers and, at the time of writing, the mad cow expert working party hasn't given us any to play with. Experts aren't allowed to say "I don't know," and, as the Consumers' Association keeps demanding, "We need to quantify the risk." Insurance companies know enough to offer JCD cover to the worried-well and there are doubtless some consumers getting out their diaries and totting up their beef consumption in the high-risk period to work out their personal liability. Let's say it's one in a million for every mouthful of dodgy hamburger eaten between 1988 and 1992 and one in 10 million now. Do you feel better? Is there really safety in numbers?

One reason why we all get into such a stew about health scares is our national dislike of science. Most of us could have a bash at critically evaluating a film or a book or the Scott report, but stick a scientific paper in front of us and we go to jelly. The roots of our ambivalence to science go right back to school, where the number of students attempting chemistry GCSE has fallen by over 70 per cent in recent years. The knock- on effect is that universities are unable to fill their science courses with good candidates, we produce even fewer inspirational science teachers and the vicious circle is complete. The majority of the population wander around aimlessly, not having a clue about the risks they expose themselves to on a daily basis until a very small one arrives on the back of a lot of media hype. Cue mass panic. Cue complete dependence on experts.

No one likes being dependent on experts and "the scientists" (whoever they are) have been given a fair old roasting in the press. Images of mad professors are as frightening as mad cows, and although many sane and literate scientists have stated their case through the media, it hasn't helped that they have drawn widely disparate conclusions from "the facts". Indeed, there even seems to be confusion about what the bloody disease should be called. Is it Jakob-Creutzfeldt disease or Creutzfeldt-Jakob? Hans Creutzfeldt and Alfons Jakob will be fuming in their graves.

Does anyone know the truth? Probably not, at least not yet. Ideally, the best way to settle the argument would be to take a random sample of healthy, meat-eating volunteers (ie, medical students), feed half of them BSE-free hamburgers and half of them BSE-full hamburgers and watch what happens to their brains over the next 10 years. This is broadly how new drugs are tried out, but, as BSE is of little therapeutic value, it seems unlikely this experiment would get past an ethics committee. So we have to rely on retrospective evidence and this, alas, is notoriously unreliable. We know the tissue changes in the 10 human victims of the new strain of CJD (sorry, Alfons) are similar to those of cows with BSE, but we can't actually prove eating BSE infected meat was to blame. It's all inference and association, evidence but not proof. And although BSE was described in Britain 10 years ago, it's a relative newcomer to the scientific community and there are plenty more hypotheses still to test before we know what it's capable of. Could it spread to lentils? Watch this space in 20 years' time.

In the meantime, it's a case of which expert do you believe, and the science of expert statements is equally confusing. In Britain, we tend to take more notice of a BBC accent but trust a regional accent. Experts of any accent can completely destroy their message if their non-verbal behaviour (seat shifting, wearing make-up) contradicts what's coming out of their mouth. Then there's the varsity factor. Do you side with the spires or the red bricks? And why are all the experts men?

Ultimately, it all comes down to risk. As with the previous national health scare (contraceptive pills), whether you smoke with your hamburger is far more likely to affect your lifespan than where your hamburger comes from. Beef farmers who knowingly fed cows and sheep to cows are not blameless, but then we all cut corners in response to market forces. Their job is isolating, stressful and has the highest suicide rate in the country. How many more will be tipped over the edge because of all this?