With a world to feed, can we afford to boycott GM?

Faced with diminishing natural resources and millions of people suffering from malnutrition, we must consider the use of GM foods to sustain the future, says Philip Dale.

Last year genetically modified crops were grown commercially in more than ten countries on a total land area about twice the size of the United Kingdom. The area is increasing significantly in China, which has almost a quarter of the world's people. Conversely, in the UK there is intense resistance to even the evaluation of GM food crops. Some campaigners have resorted to the destruction of field experiments designed to generate important knowledge as part of this evaluation. The significance of the destruction has been likened to book burning in supposedly less enlightened times.

Internationally, hundreds of millions of people must be consuming GM foods, and I can find no substantiated evidence that GM foods are less safe than conventional foods. Before they can be commercialised for food use, GM crops and the foods made from them must pass through a gruelling regulatory process - a procedure so exacting that if it were introduced for traditionally produced new crops, it would probably close many conventional crop-improvement schemes.

GM crops and foods are tested with a molecular precision that is almost impossible with food crops improved by conventional means. But is traditional crop improvement not innately safer than GM breeding? Not necessarily. Close relatives of deadly nightshade (wild potatoes) are sometimes used in traditional breeding to provide disease resistance in the cultivated potato. This carries the potential risk of introducing toxins. As a consequence, very occasionally new traditional potato varieties have had to be withdrawn because of unacceptably high levels of toxins. In practice, though, careful monitoring ensures this is rarely a problem.

Methods of crop improvement are vital to mankind. It is argued that if we had not had international crop improvement over the past 80 years, we would now need an additional land area the size of India to produce the current world food supply. Even with this significant rise in food productivity, it is estimated that about 800 million people today suffer from malnutrition.

Why then the resistance to GM crops and foods in the UK? There is no simple answer.

It was argued at a recent public meeting that science is the root of many of society's problems. BSE, thalidomide and salmonella food poisoning are sometimes quoted as examples. While scientific developments usually present new challenges, it is easy to forget history. Some 150 years ago a person's average life expectancy was close to 40 years, whereas it is now almost 80 years. This could never have happened without advances in our scientific understanding of sources of infection, the development of immunisation and surgery, and improvements in human nutrition and hygiene. Perversely, the current worries about the measles/mumps/rubella vaccine would not have arisen without the possibilities of vaccination. But it is sobering to learn that in 1839 about 54,000 people were reported to have died in England and Wales from diseases that vaccines can control today.

Debates on concerns about GM food often move quickly to issues of globalisation; the power of multinational companies; the industrialisation of agriculture, intellectual property and the patenting of living things; and the possibility of undermining traditional food production practices. I suspect there would be a good measure of agreement between scientists working on GM crops and members of the public about most of these issues. But should fear of "unknown unknowns" paralyse all future innovation?

It is interesting to reflect on the campaigning process for and against GM food crops. I find it a useful rule of thumb that if a message is entirely positive or entirely negative, it is more concerned with campaigning than with providing information in a balanced and reasoned way. Few developments are entirely good or bad. My impression is that campaigners on both sides sometimes adopt the worst characteristics of corporate practice. It is also interesting to reflect on the power-to-responsibility ratio of the different players. It is worth asking - what are the consequences to each of the players if they produce a false or faulty product?

I can find no evidence that GM crops are innately good or bad; the challenge is in how we develop and use them. This, of course, is true of most areas of innovation. What seems fairly clear is that whatever we decide to do on our small islands, it is unlikely to have much lasting influence on the foods and crops adopted by the rest of our competitive and globalised world.

If there are food-safety implications for some products, it is important that we have the best science available to address them. For those people with ideological concerns or preferences, it is important that there is segregation of GM foods, accompanied by food labelling and consumer choice. Not providing consumer choice after the import of the GM foods from North America was a major misjudgement. This was in contrast to the Zeneca GM tomato puree, marketed by Sainsburys and Safeway, that was widely accepted. The provision of choice, however, needs to be within the limits of analytical detection and of agricultural and food production practices. Absolute zero GM content in a food crop can be very difficult to achieve and virtually impossible to verify by scientific analysis. Likewise, I suspect that if we were to examine food crops for live insects and for animal fragments (hairs, skin and so on) with the kind of forensic precision required for detecting the presence of GM material, we would find that few vegetarian diets are completely free from animal material.

It is fair to say that the herbicide-tolerant GM crops being considered for commercialisation in the UK do not have a clear perceived benefit to consumers. Only those people who have spent months removing weeds from crops with a hand hoe can really appreciate the value of modern weedkillers. But the opportunities to help provide the world with wholesome nutritious crops, with minimal chemical inputs into agriculture, make GM food crops worthy of very serious evaluation as one tool in the crop improvement toolbox. It is a tool that is likely to be very valuable for the production of a range of food crops, novel crops for energy, industrial raw materials and crops with enhanced medicinal and even pharmaceutical properties. In a world with diminishing natural reserves of energy and raw material, it seems to make sense to evaluate all possible solutions to a sustainable future.

Philip Dale is a plant scientist at the John Innes Centre, Norwich, and honorary professor at the University of East Anglia, Norwich.