Nothing so scary as demon drink

It is an indisputable fact that people are living longer than ever before. It is also true that this is mainly due to improvements in what we put into our mouths. The water we drink is less likely to contain killer microbes than at any time in recorded history. Children no longer eat the dirt at their mother's knee that used to kill them like flies. The world produces enough for everyone to eat and famines are due to wars not crop failures. Yet we seem to complain more about our food. Food scares are never out of the news. Back to nature is the cry - as though modern food production and processing methods were poisoning us all.

So there is a paradox. In the western world, we have never wined and dined better. For abundance and choice supermarkets excel the cornucopias of the most imaginative artist. Starvation is not a problem for us. Prices have never been lower. Most of our food-related problems come from excess, or problems with the remoter recesses of our own minds. Obesity is epidemic. Anorexia and bulimia have never been more common. And yet fear about food among the public at large seems to be all-pervasive.

There is another paradox. It is that the degree of concern is often inversely proportional to the known risk. Consider genetically modified foods. They have been abandoned in Britain not because of the harm they have caused - so far none has been demonstrated in the United States despite their widespread production and consumption there - but because of concerns that hypothetical problems might occur in the future. It could be said that the fundamentalist pressure groups have won by playing on fears of the unknown. To invoke Frankenstein to demonise genetic manipulation has been brilliant propaganda.

So as a microbiologist happy and proud to be associated with the long line of scientists who have done unnatural things with microbes to make successful vaccines and antibiotics, I approached Was it Something You Ate? with unease.

Was it to be yet another polemic about pesticides shrivelling up our gonads?

I need not have worried. John Emsley and Peter Fell, a chemist turned science writer and a general practitioner with a special interest in diet and food sensitivity, have produced an excellent and well-written guide to the non-nutrient food components that can cause harm.

Those who believe that our food-borne ills all come from power-crazed scientists in league with monopolists aiming to take over the world will be disappointed to learn from Emsley and Fell's beautifully argued and solidly evidence-based account, that on the contrary, most of our bad eating and drinking outcomes are nature's own handiwork assisted in good measure by our own greed and intemperance. Alcohol, of course, stands out as the classical example. A whole chapter of the book is devoted to it.

Everything one needs to know about getting the maximum benefit while minimising the risk is covered under the rubrics of "The risks and benefits of drinking alcohol", "The composition of alcoholic drinks", "Alcohol and body chemistry", "Intoxication", "Detoxification", "The morning after and how to avoid it", and "Enzymes and detoxification". These titles emphasise a strength of the book: its very practical nature. While the message is simple and positive - moderation in all things - it also explains why things go wrong and how successfully to remedy them as well as how to prevent the problems occurring in the first place. So hoary old myths about hangover cures are summarily dismissed; but sound practical advice about alleviation is dispensed. Evidence about the benefits of moderate drinking is critically examined. Most of this is epidemiological, to do with studies on populations, and as with many of the researches on other food and drink constituents considered in the book, is attended by much controversy. These difficult issues are handled well. The authors do not shy away from admitting uncertainty wherever it exists - and in studies on food there is plenty - and challenging orthodoxy. All these things are not easy for scientists. The difficulty in going public about the provisional nature of most scientific evidence or in frankly admitting areas of ignorance and doubt are probably their commonest failings when talking to the public. Emsley and Fell have not fallen into these traps. Rightly, their starting position has been that the woman on the Clapham omnibus these days has a healthy and positive regard for frankness but a scepticism about the omniscience of "experts" - bred from events such as BSE.

Alcohol brilliantly illustrates the paradox that the concern of the public about food hazards is inversely proportional to risk. Add together all the victims killed in the 20th century by monosodium glutamate, food allergies, biogenic amines, salicylates in food, caffeine, sulphur dioxide, botulism, algal toxins, poisonous mushrooms, aflatoxins, lectins, food additives, nitrites, nitrates, PCBs and DDT (all non-trivial hazards nicely covered in the book) - and the number will amount to only a trivial fraction of those felled by alcohol.

But people still drink knowing the risk. They do it for the same reason that they eat Japanese puffer fish or shellfish (with a whole range of toxins ranging from the paralytic through the neurotoxic and amnesic to the diarrhetic) - because they calculate that the pleasure they get sufficiently outweighs the harm. We run into problems with our calculations only when we underestimate the risk or allow our hedonistic instincts to take over.

I recommend Was it Something You Ate? as an antidote for both ills. It is illustrated throughout with case reports that add the spice of human interest to their heuristic intent. Hazards are clearly outlined and described with sufficient quantification to satisfy the needs of anyone who wants to do their own risk assessment for chemicals in food, man-made or natural. A worthy addition to the kitchen cookbook shelf.

Hugh Pennington is professor of bacteriology, University of Aberdeen.