THE LANCET - HOW SAFE IS GM FOOD?

According to WHO, all GM foods currently used have been assessed for safety and "are not likely to present risks for human health". But exactly how sound is this evidence base? Consumers are probably right to be sceptical at present. - THE LANCET

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How safe is GM food?

THE LANCET * Vol 360, Number 9342 * October 26, 2002 *
www.thelancet.com

Surely the donation of many thousands of tonnes of emergency food supplies should alleviate the suffering of millions of hungry people, should it not? Not, it turns out, when the food has been genetically modified.

In southern Africa, hunger now affects some 14 million people. The USA has donated GM maize to help alleviate the crisis, but in Zambia the food rots in warehouses because the government believes it unsafe. President Levy Mwanawasa has even called GM maize "poison", saying he is not prepared to "use our people as guinea pigs". In some areas, citizens have rioted and looted to get to the food.

Lack of safety is just one of the charges flying back and forth. Officials in the USA, where GM foods have never been as controversial as in Europe, view the arguments as baseless, pointing out that the donated food is the same that Americans have been eating for years. But critics claim that the USA is promoting biotechnology companies, using the UN to do its protectionist bidding, and offloading surplus food it cannot sell. And African maize dealers are said to be hoarding crops in anticipation of higher prices.

The African crisis is only part of the ongoing debate over GM foods. Last week a 4-year ban on the sale and use of GM foods in the European Union came to an end. But consumers may well continue to oppose the widening introduction of GM foods into everyday life. Concerns are so pervasive that WHO has just issued a document - 20 Questions on Genetically Modified (GM) Foods - which attempts to assess advantages and disadvantages.

The advantages, achieved through improved crop protection, include insect and virus resistance, and herbicide tolerance. Public health might be improved through a greater supply of hardier strains or through products that have been enriched with vitamins and minerals, such as "golden rice", to which vitamin A has been added.

Disadvantages, though, are that GM crops may threaten biodiversity, decrease the richness and variety of foods, and make farmers dependent on chemical and biotech companies, through the use of sterile seed or chemical products that would have to be purchased yearly. Health concerns include: allergenicity; gene transfer, especially of antibiotic-resistant genes, from GM foods to cells or bacteria in the gastrointestinal tract; and "outcrossing", or the movement of genes from GM plants into conventional crops, posing indirect threats to food safety and security.

The GM foods issue is made more complex by factors that go far beyond science, including politics, international trade, and social and cultural norms. And several uncomfortable observations are hard to ignore: extreme inequalities exist between countries that donate and those that receive GM foods; recipients have legitimate worries about being bullied into accepting something they perceive richer nations to have rejected; and the international community is split over whether food or money constitutes more appropriate aid.

Without good data, the precautionary principle has often guided decisions about food safety. According to WHO, all GM foods currently used have been assessed for safety and "are not likely to present risks for human health". But exactly how sound is this evidence base? Consumers are probably right to be sceptical at present. Because regulation varies from country to country, with no international regulatory system, and because GM foods are produced in many different ways, WHO rightly cautions that foods must be assessed on a case-by-case basis. Thus, by mid-2003 the international food code created by the Codex Alimentarius Commission is expected to spell out specific principles for evaluating individual GM foods. If these principles incorporate rigorous scientific analysis, particularly of indirect effects on human health, and if they take a holistic approach toward integrating the disparate effects of GM foods, including their social and ethical aspects, they will be an important step towards strengthening the evidence for safety - evidence that must be widely communicated, among people in the developing and developed worlds alike.