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For Debate
Genetically modified foods -- food for thought We would be wise to hold off until we know more about the health, ecological and economic effects of genetically modified food. Stephen R Leeder
MJA 2000; 172: 173-174
Can we rely on the food industry regulating itself? -
What are the concerns with GM food? -
Disclosure statments -
References -
Auhtors' Details
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Advocates of genetically modified (GM) foods often assert that the
processes of laboratory genetic engineering are really no different
from those of plant and animal husbandry. This argument is not as
convincing as they expect. Those who express concern about the safety
of GM food claim that genetic engineering allows humans to do what
nature will not -- they worry that scientists cut and paste genes and
can now transfer genes between species. This gene transfer raises new
safety questions, making the production and marketing of GM foods a
matter for consideration by public health authorities.
Food safety is a public health issue. Most food is provided by private enterprise, and consumers understand that food advertising, while commercially justifiable, exhibits the qualities of advertising in general: truth is spun and packaged to make the product attractive. Regulatory mechanisms, including surveillance, have been put in place in many countries over many years to ensure food safety and to balance commercial profit with the public good. Increasingly, food manufacturers and retailers understand the critical importance of safety as well as the healthiness of their product for market share. | |||
Can we rely on the food industry regulating itself? | |||
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Not in all times or all places has the public found commercial
interest, even in food production, to be trustworthy. When outbreaks
of food poisoning occur, long-held public suspicions erupt as rage.
Furthermore, a contributing factor to the outbreak of mad cow disease
(bovine spongiform encephalopathy, or BSE) in the United Kingdom was
a change in the processing of animal feed. Altered rendering
practices, introduced in the late 1970s and early 1980s when the feed
industry was deregulated, allowed scrapie-like agents to
survive.1 This finding shocked the
community and shattered trust in commercially driven food
enterprises. The change in rendering practices paralleled adoption
of the political view that the food industry needed self-regulation
only, and the winding back of the public health food surveillance
system.
Thus, the attitude of some of the UK public to GM food was formed by their experience with BSE. GM technologies, which are profit driven (for manufacturers of GM strains and the farmers who use them), did not impress a community that felt it had been falsely reassured that food safety could be left to the producers. Although GM food safety is clearly a public health issue, in Australia at present the Genetic Manipulation Advisory Committee (GMAC) and the Interim Office of the Gene Technology Regulator (OGTR) comprise individuals who, although highly skilled, can opine only about the laboratory or clinical safety of products. The federal Minister for Health and Human Services, Michael Wooldridge, has agreed to consider appointing to these bodies a professional with extensive skill and experience in public health. Public health concerns about GM food include potential direct ill-effects from consuming the food, or imported allergens in the food, as well as their ecological impact. The histories of medicine and public health contain many examples of substances initially assumed to be safe and later found otherwise. These range from specific drugs, such as the class IC antiarrhythmic agents (eg, flecainide), which turned out to be proarrhythmic in certain circumstances,2 to more general environmental conditions, such as low level air pollution, once thought harmless but now correlated with mortality rates.3 These histories alone should deter GM food manufacturers from prejudicial paternalism in dealing with public concerns. The forms of testing outlined in this issue of the Journal by Huppatz and Fitzgerald, based on establishing substantial equivalence, are necessary but not sufficient to establish public health safety.4 Even here uncertainties remain, because of the lack of adequate benchmarks for cellular safety of non-GM foods. Most public health safety is established only by intervention followed by careful monitoring. The equivalent approach to GM foods would involve developing suitable surveillance systems for adverse events in those eating GM foods and for ecological impact. Thus, there is some justification for the introduction of these foods under surveyed conditions. Advantage could be taken of natural experiments. For example, the production and consumption of GM foods is greater in the United States than in Europe. Observational studies on the health of the two populations and their agricultural environments may at least provide clues to the long-term consequences of GM foods. This would not be easy, and the effects, as with BSE, might not be apparent for years or even decades if the latency were long between the impact of the food and its expression as illness. | |||
What are the concerns with GM food? | |||
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In the UK and elsewhere in Europe, media coverage of GM foods has been
intense and often sensational. In Australia, media concern has been
obvious, and, while claims of irresponsible sensationalism have
been made, in my opinion the quality of much of the reporting and
journalistic comment has been fair to good. An investigative series
on GM foods by Mark Ragg, health writer for the Sydney Morning
Herald, fuelled the debate in Australia.5 Much that has been written
has focused on human safety and the arguments for and against GM food
labelling, while relatively less has been concerned as yet with
environmental impact.
In recent issues of the British Medical Journal strenuous efforts have been made by editorial writers, scientific writers and freelance consultants to dampen the European "bioangst" about wayward genes in GM foods.6-8 However, as far as population and ecological safety are concerned, I believe we are at the scientific starting line: we simply don't know whether GM foods are safe, what their environmental impact will be, or how the gains will trade with the losses. In that case, says the British Medical Association, we should wait until we have evidence that GM foods are safe before proceeding. Science has yet to do its work in establishing the safety of these products.9 In a statement earlier this year, the UK's Chief Scientific Adviser, Robert May, concluded: "There can be questions of health and safety associated with some GM foods, particularly if we introduce genes coding for production of toxins against certain kinds of pests."10 May, together with the Chief Medical Officer, Liam Donaldson, also wrote that, although "there is no current evidence to suggest that the GM technologies used to produce food are inherently harmful . . . nothing can be absolutely certain in a field of rapid scientific and technological development".11 Donaldson and May urged the UK government to study the potential effects of GM food technology on health and to develop a research strategy into the technology.12 Antibiotic resistance: A further worry about GM food arises from the practice of using antibiotic resistance, which is easily established, as a marker to measure the success of a genetic modification. Antibiotic resistance is tagged onto the genetic modification, so that cells that contain the new gene are also antibiotic resistant. Were this resistance to spread to pathogenic bacteria via the GM food, it could cause great harm.9 Ecological and economic effects: Doubt about GM food does not stop at the medical boundary. Many scientists sleep easily about the safety of GM foods for human consumption after proper testing and regulation, while having nightmares about the environmental impact of these foods. For example, genes that code for resistance to chemical herbicides could be transferred from GM plants to weeds. Cultivation of GM crops on a large scale may have implications for biodiversity, the balance of nature and wildlife. Third World countries may have the most to benefit from the potentially greater productivity of GM crops, but, if the price is increasing debt to the multinationals that produce GM seed, it will simply increase the north-south wealth disparity which lies at the heart of so much appalling public ill-health.9 As Jeffrey Sachs, Director of the Centre for International Development and Professor of International Trade at Harvard University, wrote in The Economist:
Just as knowledge is becoming the undisputed centrepiece of global prosperity (and lack of it, the core of human impoverishment), the global regime on intellectual property rights requires a new look . . . now transnational corporations and rich-country institutions are patenting everything from the human genome to rainforest biodiversity. The poor will be ripped off unless some sense and equity are introduced into this runaway process.13 Concerns about the terminator gene, which prevents plants being propagated and requires farmers to repurchase fertile stock seed from the manufacturer at each planting, have drawn widespread criticism for much the same reason. This especially unpleasant commercial ploy has major implications for Third World countries. Monsanto has recently been forced to rethink its GM food strategy, with company head Bob Shapiro conceding: We have irritated and antagonised more people than we have persuaded. Our confidence in biotechnology has been widely seen as arrogance and condescension because we thought it was our job to persuade. But too often we forgot to listen.14In the meantime, a healthy scepticism about the massive commercial interests in GM food is warranted. The moratorium called by the British Medical Association has much to commend it, especially for those who believe that human progress is best served when we listen to the guidance of science -- even when it says "I don't know".9 | |||
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Disclosure statement | |||
| No conflicts of interest. | |||
| References |
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| Authors' Details |
Faculty of Medicine, University of Sydney, Sydney, NSW. Stephen R Leeder, FRACP, FAFPHM, FFPHM, Dean.
Reprints will not be available from the author. ©MJA 2000
Readers may print a single copy for personal use. No further reproduction or distribution of the articles should proceed without the permission of the publisher. For permission, contact the Australasian Medical Publishing Company. Journalists are welcome to write news stories based on what they read here, but should acknowledge their source as "an article published on the Internet by The Medical Journal of Australia <http://www.mja.com.au>". <URL: http://www.mja.com.au/> © 2000 Medical Journal of Australia. We appreciate your comments. | ||