ALDES Briefing Note on GM FoodsWhy does the world need GM food? In the time of Malthus, at the end of the 18th century, global population was about 1 bn. By 1960 it had reached 3bn, and by 1990 5.3bn. It is just under 6bn now and the UN mid forecast is 8bn by 2020 AD. It is something of a miracle that, outside war zones, virtually all the world's people are being fed. The 6 fold increase in population since 1800 has, of course, required a 6 fold increase in food production. It has been achieved by cross breeding of plants and animals, increasingly intensive agriculture (with more mechanisation and high energy inputs), and heavy use of agro-chemicals, ie fertiliser, pesticide and herbicide. The consequences have included pollution (especially of some watercourses and water supply aquifers), loss of wildlife, and worries about food safety, especially salad and fresh fruit crops. Genetic modification (GM) appears to offer a more efficient route to improve crop varieties. It could reduce the volume of agricultural chemicals whilst still increasing food production. Why can't we simply change to organic farming? There are about 1,200 organic farms out of the 150,000 farms in the UK at present. This is less than 1% even though farmers can receive £250/ha (soon £450/ha) over 5 years to convert. The problem is simply that yields from organic farming are lower (less than 2/3rds) and/or require more manpower than conventional methods. Inevitably organic food is more expensive. Though a larger part of the vegetable market could become organic, there is little prospect at all for grain. It should be noted that even organic farming is not entirely benign. Crops can be contaminated by toxic moulds, such as claviceps purpurea which affects grain crops and can cause convulsions. Organic fertilisers leach nitrates into aquifers just like chemical varieties. It may sound a paradox, but GM is working towards the same goal as organic farming - the use of less chemicals. The two approaches could converge if organic farmers start using selected GM seed varieties. There is a GM maize (Novartis Bt) which has been modified to include genes from a soil bacterium, bacillus thuringiensis (Bt). Bt makes proteins which are toxic to insects eating plant. Preparations of Bt have actually been used by farmers as a form of "natural" insecticide for many years and is approved for use in organic farming. Bt is not toxic to man. It would be possible for organic farmers to eliminate the need for insecticide by using the GM seed variety. But there is plenty of food - what about the food mountains? The food mountains are nowadays food "hills" with reducing amounts of butter, grain, and so on. One reason is payment for "set-aside". In the UK in 1996 a significant area (509,000 hectares) was set aside. (This compares with 4,721,000 ha of arable crops and a total agricultural area of 18,401,000 ha.) The EU (and USA) could clearly produce more food. However this would still require agro-chemicals. So what is GM? DNA, the "code" which defines living things, is made up of long strings of "genes" and "gene promoters". A gene is a "template" or "pattern" for making a specific protein. Gene promoters are "enzymes" (biochemical catalysts) which "switch on" their genes when given specific stimuli. One gene in the human body makes insulin. The insulin promoter detects sugar in the bloodstream and switches on the gene which converts the sugar to energy. Some genes are common to plants, animals and humans, others not. Plants contain tens of thousands of genes. Selection of the best seed varieties and animal species is known to have occurred for at least 10,000 years in SE Asia. Cross breeding, which attempts to blend desirable characteristics from two plant strains into one (eg a high yielding wheat with a quick ripening one, for use in short growing seasons as in Canada), began seriously in the 19th century, though the breeding of mules (a cross bred donkey and horse) has occurred for 3000 years. Cross breeding is clearly a man made intervention leading to artificial or "unnatural" genetic arrangements, though it is well accepted. However it is a slow and somewhat hit and miss affair. The ability to replace single genes, first developed in the 1970s, was seen as a huge breakthrough. GM scientists claim it is more precise and predictable, and therefore safer. Cross breeding transfers 2000 or more genes at a time with unknown side effects. Genetic engineering changes 2 or 3. How does GM work in practice?
If GM's so good, why is there opposition? At root, probably because GM (which is proceeding apace in medicine as well) has a kind of "Brave New World" feel to it. It is as though, once the scientific breakthrough was made, a dam of ideas burst leaving us awash with the uncertainty of new discoveries. Citizens are bewildered at the pace and extent of change. There is an understandable reaction of "hold on a bit - things are going too fast". After all, food and food safety effects every single person. Unhappily, unlike other countries such as France, public appreciation of science in the UK is poor, and, perhaps aided by a press keen on scare stories to sell its newspapers, there is an uneasy tension between public and scientist. The cry "look at BSE" ignores the incredible transformation in the diversity and comfort of our lives brought about by science - and the simple fact that we are being fed at all! Some of the opposition is fed by genuine environmental worries. Other by an undercurrent of suspicion of big business and the profit motive itself. There is no doubting that the potential impact of GM is vast. A substantial part of our agriculture could be GM within 25 years. It is right to be cautious. How do we know GM food is safe to eat? It is an uncomfortable thought that eating most food carries risks. Recently the BSE worries have moved to lamb. We used to avoid pork when there was an R in the month for fear of tape worms. Chicken and eggs have been associated with salmonella, and milk with listeria. Butter and cheese can put up cholesterol levels. Cakes and the like invite dental decay and obesity. Vegans take risks of omission. Anaemia results from insufficient iron, zinc and vitamins B6 and B12. But some say taking too much B6 is risky. Even something as innocuous as a peanut is lethal to some, and so it goes on. The Independent recently claimed that "Food scares can harm health". Perhaps porridge is the answer! GM food is being examined more closely than non-GM food. Indeed most food on the market has never been tested. Logically it should be safer. Nevertheless there is no research that can predict what might happen 40 years from now. It is likely some problems will arise, and vigilance remains necessary. What are the environmental dangers? The truth is, we do not know. Scientific history suggests unforeseen problems will arise. Unhappily, for every generation of new wonder drugs which prolong and improve life, there will be a disaster like thalidomide. Mankind is not all-seeing. It is the question we don't realise we should ask, which trips us up. It was the Tay bridge disaster which awoke engineers to the complicated stresses caused by high winds, and the Comet crash at Elba, to the danger from metal fatigue. BSE is another good example. Though a spongiform brain disease (scrapie) had been known in sheep for over 200 years, the numbers affected by its equivalent in cattle (BSE) and humans (CJD) was small. The notion that recycling cattle remains could be harmful seemed unreasonable, at that time. It took about 5 years for the truth to dawn, and a little more to wrench the system round to a programme of BSE elimination. Even then there was little reason to be concerned for human health. There was no evidence over 200 years that scrapie had passed to humans. Why should BSE? Migration of disease across species is remarkably rare. It was only by 1996 that sufficient human brains had been examined to indicate the awful possibility that BSE might be responsible for a new variant of CJD, and that an entirely new sub-viral organism, a prion, might be responsible. The words "might be" is deliberate. It is still not certain. One casualty was reported to be a vegetarian. The economic damage to farmers and this country is now history, and the blessed gift of hindsight is helping us pinpoint the errors and those who made them. Though one unnecessary death is too many, it is thought the toll (27 so far) may total less than 3 days carnage on the roads. All we can now do is pore over the lessons and learn from them. Drugs, aircraft, bridges and so on are more advanced and safer due to the lessons learnt from past failures. Thankfully, the doom merchants usually turn out to be wrong. One GM concern is that the GM genes may "escape" into other plants causing havoc. There is some evidence that the gene which resists herbicide has found its way into the weeds it is trying to kill, making them resistant. This, it is pointed out, could lead to an "arms race" between new herbicides and clever weeds. French scientists at the National Agricultural Research Institute at Le Rheu, have artificially cross bred a GM oilseed rape plant containing a gene giving resistance to the herbicide Basta (glusofinate ammonium) with wild radish weed. After 4 generations of cross breeding the resistant gene became incorporated into the cross bred weed and could then spread among non-hybrid weeds. In the wild, cross breeding occurs through pollination. Plants contain both male (the stamen) and female (the stigma) parts. Pollen contains the male DNA and is transferred within a plant or between plants by wind or insects (eg via a bee seeking nectar). The natural world arranges that plants of one species invariably pollinate each other, not different varieties. Garden roses do not cross pollinate daisies for example. Nevertheless pollen can travel long distances and the main risk is of cross pollination with the wild varieties of GM crops. Other research has suggested that GM plants are more likely to cross pollinate than non-GM. In other words the inserted genes are somehow "looser" Generally the crop varieties which provide our food are highly specialised, and therefore relatively frail. Many cultivated flowers, such as carnations are dependent on pesticides to protect them from insects, fungi, and other pests. Consider the winners in a garden or allotment left alone for a year - not the cauliflowers, but the weeds. GM scientists developing herbicide resistance have an incentive to prevent weeds taking up resistant genes, because it would make their product redundant, but this clearly a matter which merits close monitoring. Another issue is the planting of GM and non-GM varieties in adjacent or nearby fields. The probability of cross pollination is high here, and some non-GM plants could yield GM fruit (and vice versa). This is not necessarily a health risk, but separation, which is required now, should continue for the time being. Are there risks to wildlife? English Nature is particularly concerned about the threat to the corn bunting and linnet because the seeds and insects on which they grow could be wiped out. Nature interacts in a kind of slowly changing equilibrium, so the reduction of a particular insect or plant will inevitably have impacts on other species higher or lower on the food chain. It should not be assumed, however, that the effects will be adverse. A GM sugar beet trial in Cambridgeshire which allowed reduced use of both herbicide and insecticide, actually found increased numbers of aphids and the insects which feed on them. Indeed it is probable GM will help. For a start, GM should reduce the land required for agriculture, leaving more for forest, and should reduce the hazards from chemicals. Is it true non-plant genes are being used? Yes. As noted earlier, some of the more common genes, especially those dealing with survival, exist in plants, humans and animals. In some cases a common gene may be more easily obtained from an animal or bacterium, than plant. The suggestion that an anti-freeze gene in fish has been used to make strawberries more frost resistant is contested. Even if true, it is not necessarily a matter of concern. After all, we eat a great deal of fish. In current medical trials a retrovirus of mouse origin is being used to deliver a gene to kill glioblastoma brain tumour cells. Life expectancy is currently about 10 mths and there is no other cure at present. Again the use of non- plant genes is not necessarily a matter for concern, though it may raise ethical issues. Aren't we trying to play God? There is no objective answer to this. Some, including perhaps Prince Charles, would argue that DNA is the key to life and we have no right to mess with it. Others would say God has given us the intelligence to pursue knowledge and wants us to use it for the benefit of mankind. One truth is that nature is not sentimental. Mankind has been pitting its wits against it for several thousand years. Certainly global population would not be at present levels without mankind's huge effort to survive. Shouldn't we be worried by multi-nationals rushing to making huge profits? Liberal Democrat philosophy is to encourage and reward innovation and expertise. The party has always been anti-monopoly, but never "anti-profit". There is a legitimate fear that some GM products will be so good that they will rapidly displace existing crops, and give one or two GM companies a dominant market position. This is a commercial rather than environmental issue and is outside the scope of this note. Clearly it needs very careful attention. A linked matter is that having displaced a conventional crop, problems or health risks might be found and there will be "no way back". It is important to guard against this, although it should not be difficult to do so. There are already seed banks with thousands of varieties. It might be prudent to control the rate of introduction of each GM crop over, say, the next 25 years, even if this means providing subsidy for non-GM varieties for part of that time. Another fear concerns 3rd world farmers. Because GM seeds may be sterile (if they are, this will reduce worries that genes will "escape" and spread), farmers who use GM seeds will no longer be able to supply seed themselves and will find themselves "over a barrel" when they come to buy again. This argument seems somewhat fanciful though it is possible the 3rd world will need help to finance GM developments. Lastly, there is a fear that big multi-nationals will use their political muscle to over-ride scientific caution. Though all companies carry a legal duty of care, there are various modes of financial escape. One safeguard is that the GM market is potential huge, and long term. It would be a foolish company that risked its considerable investment by an unnecessary tragedy. If GM is ok, why are so many scientists opposed? It is a proper function of scientists to look for risks as well as benefits, and, especially after the BSE debacle, to warn of possible problems, so that they can be researched. This is not opposition but warning. The only UK scientist known to be outrightly opposed is Prof Brian Goodwin of Schumacher College, Dartington. He believes the use of viruses to convey genes into plants could combine with wild-type viruses to create super pathogens spreading genes and disease indiscriminately. He is concerned too that GM could create new toxins, and allergens which are currently unknown and are not being tested for. Is anyone regulating GM development? Yes. Some comments suggest there is little or none, but in fact it is extremely onerous. When a company, research establishment, or university wants to move its GM trials out of the laboratory, approval has to be sought from the Department of the Environment, Transport and the Regions (DETR). The DETR is advised by an independent committee ACRE - the Advisory Committee on Releases to the Environment, which is itself supported by a number of specialist committees and technical sub-committees. The ACGM - Advisory Committee on Genetic Modification - covers GM crops. Consents (if granted) give the details of the modifications and the purpose of them; specify the location and size of plots and margins; the timescale for planting (which may be up to 10 years); the reporting requirements, and any other necessary restrictions. Examination of the environmental risks from things like cross-pollination, and dangers to wildlife are demanded. 57 consents were given between 1986 and 1992 before the EC directive 90/220 came into force, which required that all details were placed on public registers held regionally. Since the opening of the register on 1st Feb 1992 until mid May this year, 154 further consents have been requested. Unhappily this openness has facilitated the sabotage of some trial crops, actions which must be condemned without equivocation. Of the 154 applications, almost half (71) concern oilseed rape, with substantial numbers for potatoes (25) and sugar beet (27). Applications may cover several sites. In the first quarter of 1998 13 applications were made which covered trials on 25 sites. EC 90/220 also regulates commercial growing. Approval to grow for the market is sought first from the competent national authority in which the crop is to be grown. (In the UK this is ACRE). Another very tough, detailed risk assessment is demanded. If approved, comments are then invited from all other competent authorities in the EU. If differences can not be reconciled, the European Commission decides by qualified majority vote. Approval allows the crop to be grown and marketed in the host country. EC 90/220 also covers the handling and sales of imports from outside the EU and are dealt with in a similar way There are two additional steps.
Interestingly the GM tomato strain used in the puree, although grown in California, was developed by the UK company Zeneca (formerly part of ICI) and Nottingham University following research begun 10 years ago. Are GM foods properly labelled? It is a struggle. Labelling is an EU responsibility, and despite support from the UK government the Commission has only just finalised agreement for GM soya and maize (EC 1139/98, 1.9.98). GM puree however has been labelled from the start. Is there any action we should be taking? In any assessment of a new technology, one needs to ask not only "what are the consequences of using it?", but "what are the consequences of not?". Not using GM crops mean continued heavy agro-chemical use in the UK with all the environmental problems that is causing, and real problems of feeding the increasing millions in the rest of the world. There are substantial environmental costs of doing nothing. As far as can be seen at the moment the potential benefits of introducing GM foods are substantial, whilst the risks to ourselves and the environment, appear to be modest. However, the consequences of something going wrong could be great. The best policy seems to be to "inch" forward with caution. That means (a) making no concessions to the onerous environmental risk assessments that are currently required at both trial and commercial stage (b) monitoring all adverse environmental and health effects on a global basis in case the envelope of risk assessment needs to be extended further There is not a huge backlog of GM crops waiting to be approved for commercial growing. Some crops being trialled now will not approach the market for at least a decade. Moreover GM is diverse and must be considered on a crop by crop basis. A 5 year moratorium to do "general" research would not achieve much. There is a further disadvantage that overseas suppliers could still export their crops to this country (there would be no grounds to stop them under the terms of free trade), and would be free to build up their markets while our own farmers have to sit on their hands. A better approach would be to institute a moratorium on the more advanced genetic modifications such as those involving antibiotics, whilst allowing the more innocuous developments through, hopefully, gaining public confidence through their success. |