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The Impact Of Genetic Modification
On Agriculture, Food And Health

An Interim Statement of the British Medical Association
Board of Science and Education
May 1999


"Evolution is all about assembling the improbable by tiny steps; and not until the unlikely has been reached do we notice just what it can do. Genetically engineered organisms will, like any other creature, evolve to deal with their new condition. It is fairly certain that some of them will cause problems. Low risk is not no risk. The question is one which is universal in economics - will the benefits outweigh the costs?" (Steve Jones, 1993)

Genetic modification involves the insertion of genes from one organism into another to produce altered genetic material (DNA). The technology is being used to alter certain properties of food crops - for example, to make plants herbicide resistant, or delay rotting in tomatoes. As its use has become more widespread and sophisticated, there is increased public concern over the safety of genetically modified plants, within the food chain and within human foodstuffs.

The BMA through its Board of Science and Education has taken sustained interest in the environmental impact of agricultural chemicals and agricultural practices. In 1992 the BMA policy report Pesticides, Chemicals and Health considered the use of genetically modified (GM) herbicide resistant plants as alternatives to the use of pesticides. The report reflected the view of the Royal Commission on Environmental Pollution (published in 1989) that it is "essential that the release of genetically modified organisms (GMOs) is conducted from the outset under appropriate statutory control". In 1994 a further BMA report stated that "The techniques of genetic modification have the potential through application in agriculture, medicine and technology to increase the well-being of people and to promote the health of the population by disease prevention".

The BMA also recognised that "At this stage in the development and application of genetic modification it is not possible to provide any guarantees against, or insurance for mistakes. When we seek to optimise the benefits over risks, it is therefore prudent to err on the side of caution and above all to learn from our accumulating experience". The concern with risk assessment and the environment has been further examined in the 1998 BMA publication Health and Environmental Impact Assessment - it concluded that decisions regarding the environment and health should be evidence based and that where there is uncertainty the precautionary principle should always be applied.

Recent uncertainty over the effects of planting GM crops and the consumption of GM foods has led to some concern in the medical profession over the regulation and safety of GM foodstuffs. At the BMA's Annual Representative Meeting in 1998 it was resolved that:

"This Meeting is concerned about the impact that genetically modified foodstuffs may have on our long-term health and calls upon the BMA Board of Science and Education to examine objectively the scientific evidence and commercial pressures on the issue".

The BMA Board of Science and Education decided that an interim report should be produced as genetic modification techniques are quickly evolving and are the subject of fast moving political debate and legislation. The interim report considers some of the main health, environmental and regulatory concerns that have been raised over GM foodstuffs, and presents recommendations which will inform the wider decision making process.

This paper will focus on the use of GM products in foodstuffs, and does not directly address the use of GM products in pharmaceuticals. GM products in pharmaceutical products are of great potential therapeutic benefit, and are licensed and controlled under the Medicines Act. They are therefore subjected to separate and rigorous tests, including extensive toxicological testing, and comprehensive risk assessment.


BMA Recommendations

Environmental precautions and public health risks

  1. The precautionary principle should be applied in developing genetically modified crops or foodstuffs, as we cannot at present know whether there are any serious risks to the environment or to human health involved in producing GM crops or consuming GM food products. Adverse effects are likely to be irreversible; once GMOs are released into the environment they cannot be subject to control. It is therefore essential that release does not take place until the level of scientific certainty is sufficient to make the risk acceptable. This will require a comprehensive cost/benefit and health impact assessment, comparing genetic modification with other forms of agricultural engineering. The BMA has provided guidance on how health and environmental impact assessment could be conducted to assist in determining the degree of environmental risk.

  2. Careful consideration needs to be given to the effect of GMOs on farming practices, the countryside and wildlife and we therefore recommend a moratorium on the commercial planting of GM crops in the UK. The moratorium should continue until there is scientific consensus (or as close agreement as reasonably achievable) about the potential long-term environmental effects.

  3. GM foodstuffs should be segregated at source, to enable identification and traceability of GM products. This is important as there are considerable doubts about the behaviour of GMOs once they are released into the environment, and this will also facilitate monitoring in the interests of public health. It is unacceptable that at present some GM and non-GM products are mixed at source, and are not adequately labelled.

  4. If the biotechnology industry persists with its stance of mixing GM and non-GM products the Food Standards Agency should consider banning imports of such products (until such time that possible hazards, if any, have been identified) or insist that such products are labelled to indicate that there is no guarantee that products are GM free.

  5. The regulatory committee approved standard separation distance between GM and non-GM crops should be reviewed in the light of new research on the risks of cross pollination.

  6. There should be a ban on the use of antibiotic resistance marker genes in GM food, as the risk to human health from antibiotic resistance developing in micro-organisms is one of the major public health threats that will be faced in the 21st Century. The risk that antibiotic resistance may be passed on to bacteria affecting human beings, through marker genes in the food chain, is one that cannot at present be ruled out.

  7. Because of the potential scale of use of GM material in the environment and in the food chain, there is a need for a considerable strengthening of the UK disease surveillance systems, both in their scope and depth. Disease surveillance and event monitoring procedures will need to be sufficiently robust to deal with the potential emergence of new diseases associated with GM material which will be obscure and difficult to diagnose.

  8. The risk that GM crops may increase the use of herbicides and pesticides in the environment needs to be comprehensively assessed to determine their full environmental impact. Biotechnology companies must provide satisfactory evidence that such chemical use will not increase - otherwise the use of such GM crops must be regarded as being environmentally unacceptable.

    Further research

  9. The BMA is concerned that while genetically modified foodstuffs could contribute substantially to improving nutrition and health (not only because good nutrition leads to good health but because vaccinations could be carried out through administration of GM foods), further research needs to be conducted on the possible health risks of GM foods consumption. In particular further research is needed on the mechanisms of allergic reaction to GM products and the health risks arising from antibiotic resistance.

  10. There should be more long-term research into the environmental effects of GMOs - in particular to consider the cumulative effect of GMOs in the environment and the food chain and the fate of metabolic (or digestive) transgenic DNA in animals and human beings.

    Regulatory process

  11. The Food Standards Agency with statutory power should be introduced urgently and as a priority consider the wider and long-term implications of GM food on human health. This will provide greater regulatory coherence than the current case by case approach to GMO production and consumption, and provide a single reference point for research on all aspects of the food chain, from 'plough to plate'. The inclusion of medical experts in existing and new advisory committees is essential.

  12. Once a scientific consensus is reached on the safety of GM crop planting, the Food Standards Agency should introduce new regulatory controls to conduct post-release monitoring and surveillance of commercially grown GM crops.

  13. Comprehensive health and environmental impact assessments should be applied to all GM crop site applications, and be open to public scrutiny. Evidence of safety submitted by Biotechnology companies should be openly presented and subject to critical peer review. Commercial secrecy should not take precedence to openness of information in matters relating to public health.

  14. Breaches of crop site regulations should be met with appropriate fiscal measures. In particular, fines for companies which ignore legally required risk control measures should be of a sufficient nature to act as an effective deterrent.

    Third world development

  15. Regulatory procedures in the third world should be as rigorous as those in developed nations in order to prevent companies escaping legal constraints. There should be a co-ordinated effort by industries and governments worldwide to ensure that the regulations and provisions affecting GM products do not favour the developed countries at the expense of other more vulnerable developing nations.

  16. Export of GM foods to developing countries should be carefully monitored to ensure that packaging, labelling and possible environmental consequences are fully regulated.

  17. The UK Government should consult with European and other governments to support a review of the World Trade Agreement to ensure that governments rather than companies determine whether countries accept with, or without restrictions, the importation and use of GM seeds, plants or foods.

    Consumer choice - areas of public concern

  18. Governments should ensure that non-genetically modified foods continue to be widely available and affordable to consumers, and that GM foods are labelled in a consistent and understandable manner.

  19. More information on new scientific technologies, especially developments in biotechnology, should be made available to the public. This should include information about the costs and benefits in terms of health, the environment, the economy and other social considerations. The Government and the biotechnology industry should not ignore public concerns, and must seek to allay fears through greater dialogue, effective consultation and transparency of information. This should include a centralised information service for public enquiries relating to GMOs, and an easily accessible database of trial crop site consents, and research evidence. Unless public confidence over GM crops and GM food is considerably enhanced, there is a danger that medical biotechnological advances will be similarly rejected by the public, at great cost to medical progress.


British Doctors Call for Halt to GM Crop Trials
Reported by Lim Li Ching

The British Medical Association (BMA), which has a membership of over 120,000 and represents more than 80% of British doctors, has called for a moratorium on GM crop trials in Scotland.

In its submission to the Scottish Parliament's Health and Community Care Committee on 20 November 2002, the BMA urged that GM crop trials be stopped immediately, as a precautionary measure to safeguard public health. It said that "insufficient care" has been taken over public health and concerns are "serious enough" to justify an immediate end to the trials.

The Health Committee, in response to a petition from the Munlochy GM Vigil, had launched an inquiry into the health impacts of GM crops. The inquiry is considering whether the Scottish Executive's decision to approve the testing of GM crops at a number of sites in Scotland will have negative consequences on public health.

The BMA originally called for a moratorium on the planting of GM crops in 1999. At that time, the doctors had already expressed deep concerns about the impact of GM foods on long-term health and had called for a halt to any further planting of GM crops until trials could be assessed for environmental contamination and ecological impact. Its latest submission is made with the benefit of more information, and notes instead that the numbers of crop trials have increased, without the requisite thorough assessments or adequate public consultation.

The BMA's answer to the Committee’s question as to whether the Executive should prevent GM crops trials from continuing on the grounds that it is against the precautionary principle was a resounding "Yes". Citing the lack of a robust and thorough search into the potentially harmful effects of GM foods on human health, the BMA urged that on the basis of the precautionary principle, farm scale trials should not be allowed to continue. It stated that the concerns doctors have about the impact GM foods may have on long-term health are serious enough to warrant a precautionary approach.

It urged that GM crops be subject to rigorous and comprehensive risk assessment prior to farm scale trials, including the consideration of longer-term environmental and health consequences. Only once such rigorous assessment is made should field trials be allowed. And until these risks are fully understood and quantified by field trials, there should be a moratorium on any further planting of GM crops on a commercial basis.

Currently, the BMA said that not enough is known to give an accurate risk assessment of the health impact of GM crops on the health of local communities. It thus called for independently funded and reviewed research in the public domain, which considers the long term health and environmental health impacts of GM crop planting and the consumption of GM food. Until such research is conducted, GM crops should not be freely cultivated and extension of the current farm-scale trials would be "ill advised" and "potentially irresponsible".

According to the BMA, the most worrying issue is the potential danger posed by GM crops in creating antibiotic resistant pathogenic organisms. ISIS has been consistently drawing attention to this issue and to the dangers of horizontal gene transfer. The BMA asserted that there is evidence that these genes may be transferred to non-GM plants and that there is significant risk of antibiotic resistance transferring "possibly into pathogenic organisms causing human disease".

Any increase in the number of resistant micro-organisms through the transfer of marker genes from GM foods would potentially have very serious adverse effects on human health.The BMA cited the use of antibiotic resistant markers in GM foods as a completely unacceptable risk, however slight to human health, and called for the use of antibiotic resistant markers in GMOs to be prohibited immediately.

Another concern expressed was the potential adverse effects of allergenicity on human health from GM products. The BMA called for further research and tests on GM foodstuffs for allergenicity, pending which there should be an open-ended moratorium on transgenic products, and especially on introducing nut genes and proteins etc. into cereals.

The BMA warned that routine health surveillance currently in place would not pick up adverse effects on the health of people living in the vicinity of GM crop trial sites. It thus called on the Executive to monitor the health of people living near the trial sites and to track any subtle changes in these areas.

Dr Charles Saunders, Chair of the BMA's Scottish Committee for Public Health Medicine and Community Health, cautioned that the absence of monitoring meant any potential side effects experienced by people living near GM crops trials were not being picked up. He said, "There are certain mechanisms within the NHS with regards to human health in relation to food that tend to pick up known organisms and known conditions. They are quite good at picking up things that kill people, but are relatively poor at picking up things that don't. I would have no confidence in their ability to pick up unusual symptoms in people living near GM trial sites."

Following the BMA's submission, Robin Harper, Green MSP, tabled a motion in the Scottish Parliament, calling on MSPs of all parties to demand the halting of the trials. The Scottish National Party, the main opposition party in the Parliament, also threw its weight behind moves to have the trials stopped, saying there was now overwhelming evidence against them continuing.

However, the Scottish Executive continues to insist that there is "no evidence" that the field trials are inherently harmful and denies that public health is being put in danger. Ross Finnie, the Scottish Minister for Environment and Rural Development, says that he has no plans to introduce a moratorium on GM crops.

  • Sources

  • Submission of the British Medical Association to the Health and Community Care Committee on the health impact of GM crop trials

  • 'Doctors want GM crop ban', BBC News, 20 November 2002

  • 'Crop trials must stop, say doctors', The Scotsman, 19 November 2002

  • 'BMA report leads to call for halt on GM crop trials', The Scotsman, 20 November 2002

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