The Case Against GM Crops

Article by Eva Novotny, September 2003

1. What is GM (Genetic Modification)?

2. Are GM foods safe to eat?

3. Are GM crops safe for the environment?

4. Actual performance of GM crops

5. Economic consequences of GM crops

6. Motivation of GM companies

1. What is GM (Genetic Modification)?

Traditional breeding crosses varieties of plants or animals that are closely related genetically. A pig and a cow, for example, could not produce offspring. Yet genetic engineering, otherwise known as genetic modification, has put genes from flounders into strawberries, and genes from spinach into pigs. The resulting organism contains combinations of genes that have never before existed in nature.

DNA (deoxyribonucleic acid) ) is a double-stranded, helical chain of chemical structures comprised of carbon, nitrogen, oxygen, phosphorus and hydrogen atoms. Genes are regions of DNA that carry information, or instructions, about how the host organism is to function. Contrary to popular belief, however, and indeed to the basis upon which genetic engineering operates, there is not a one-to-one correspondence between particular genes and particular characteristics; a gene can contribute to more than one characteristic and, conversely, more than one gene can contribute to a particular characteristic. Moreover, the function of a gene is influenced by its placement with respect to other genes. Yet the engineers have no way of controlling the position of an inserted gene, which finds itself in an indeterminate location. It is not surprising then, that many strange and unwanted effects are observed when foreign genes (transgenes) are inserted, resulting in such phenomena as green salmon. In fact, most of the hosts that successfully accept the transgene have to be discarded by the developer of the new ‘product’ because they exhibit undesirable traits. Neither is it clear what, in the end, has actually gone into the host. When independent scientists analysed the genetic structure of Monsanto’s Roundup Ready soya beans, they found multiple copies of the insertion Monsanto claimed, together with a substantial sequence of other genetic material that Monsanto apparently did not know about. The function of this extra material is unknown. In fact, the function of much of ordinary DNA is still not understood; it is called ‘junk DNA’. With all these uncertainties in what is claimed to be a ‘precise’ technology, there is no guarantee that harmful traits not as obvious as the wrong colour will have been screened out.

To effect the transfer of genes from one species or kingdom to another, geneticists need a carrier for the gene in order to invade the cell of the host organism. For this purpose, viruses or bacteria, or an injected solution of the gene can be used. In other instances, tiny particles of gold onto which the genes have been made to adhere are blasted into the cell from a kind of gun. The complete ‘package’ that is inserted also typically contains a genetic switch to turn the gene on (a promoter) and a genetic flag (a marker) that will tell the geneticist whether the ‘package’, and therefore the desired gene, has indeed been taken up by the host.

Both the promoter and the markers that are commonly used are problematic in themselves. The promoter, usually taken from the cauliflower mosaic virus, is particularly likely to break up and recombine with other viral fragments already present in the host. This can lead to the creation of dangerous new viruses that could cause disease. In addition, the promoter is so strong that it causes excessive activity that could lead to cancer. The argument that there is no cause for concern, because people have for many years been eating virus-affected cauliflowers without ill effects is specious; cauliflowers contain the virus in its natural form, whereas, in the reduced form used in genetic engineering, the virus can infect not only cauliflowers and other brassicas but all plants and animals, including human beings. This point has never been satisfactorily answered by the genetic engineers.

Antibiotic-resistance marker genes are often used as flags to signal which potential host plants have accepted the gene package: only those plants that can withstand the application of the antibiotic also contain the desired gene. This use of antibiotic-resistance genes may, however, be promoting the generally increasing resistance of pathological bacteria to antibiotics that are used in human and veterinary medicine.

Genetics remains inadequately understood and uncontrollable, and it is dangerous to create living things that may in future be revealed to possess properties or behaviours causing harm to themselves or to other life forms on this planet, including ourselves.


2. Are GM foods safe to eat?

The GM industry assures us that their products are safe to eat. Yet there is very little evidence to confirm such statements. Clearly, the millions of people in the United States who are unknowingly eating GM food (there is no labelling and hence no choice) are not dying in droves. Nevertheless, it is possible that more subtle deterioration in health is taking place. There is no monitoring for any effects of consuming GM food, and it might take years to become apparent. There was, however, one dramatic case: a nutritional supplement, L-tryptophan, caused the deaths of 37 people (before the authorities stopped counting) and caused permanent disability in 1500 more. Unfortunately, it was no longer possible to trace the exact manufacturing procedure by the time the harm was discovered. The company, which had long been manufacturing the supplement without incident, insisted that the only change in its procedure was the use of a GM source.

Both in the United States and in the United Kingdom, a ‘fast-track’ approach has been adopted by the government agencies responsible for food safety. If tests comparing certain nutrient levels in a GM variety and non-GM varieties indicate that the levels are similar, the GM variety is passed as being ‘substantially equivalent’ and safe for marketing. The fact that the food contains genes from another species is ignored. There is the possibility, however, that new allergens or toxins may have been introduced along with the intended new trait. The dangers of antibiotic-resistance marker genes and the use of a powerful and highly active promoter have already been mentioned in the first article of this series.

It is not only the genetic modification that is cause for alarm. The herbicides for which most GM crops are designed are highly toxic not only to weeds but to all plants and also to animals, including human beings. Not only an individual but also a foetus can be affected

Very few investigations have tested the effects of GM foods on animals, and none has been carried out on human beings except for a study that revealed transfer of GM genes from a GM meal to bacteria in the human gut. The latter study has not been followed up to determine the consequences of the horizontal gene transfer (i.e., direct transfer, not passed ‘vertically’ from parent to offspring.) Experimental rats fed GM potatoes suffered damage to their internal organs. Viral DNA fed to mice was later found in the white blood cells, liver and spleen and was even passed on to the offspring. Company-sponsored studies of GM maize fed to rats and chickens, however, claimed that no adverse effects had occurred; but independent scientists who re-examined these results drew the opposite conclusions (Chardon LL Hearing). The government tells us that we must rely on the safety tests carried out by the GM industry itself. It has been shown, however, that industry-based scientists are often under constraint by the companies they serve to alter their experimental results or otherwise to produce the results the company requires. Where legislation is concerned, large companies have powerful influence over governments, and ‘revolving doors’ often connect influential legislators and company personnel.

Many anecdotes exist of both wild and domestic animals refusing to eat GM crops or of losing weight when they have no choice but to eat them. When cattle broke into a GM trial of maize in the United Kingdom, they did not eat any of it. Cattle have been known to break down a fence to reach and feed on non-GM maize, having waded through a field of GM maize to reach it.

While endorsing GM crops, the Royal Society has published a document recommending that, if these crops are introduced into the United Kingdom, there should be ‘post-marketing surveillance’ of the nation’s health, especially in high-risk groups such as infants. The nation should query the wisdom of such a situation. Why are we being asked to put ourselves and our children at risk of serious harm, when ordinary food is plentiful and varied?


3. Are GM crops safe for the environment?

Farm-scale evaluations of GM crops have been taking place in Britain over the past three years. It has been pre-supposed that they are safe to eat, and the trials are intended to address one question only: is the chemical regime associated with the growing of GM crops more harmful to certain species of fauna than is the regime for conventional farming? Even for their limited remit, these crop trials have been badly designed. No base-line data were taken with which the results could be compared. The fauna do not include mammals, soil micro-organisms or most other organisms that live in soil, although soil organisms are vital for soil fertility. Earthworms are monitored only in a perfunctory manner. The farmers conducting the trials have been given special instructions by the biotechnology companies that would not apply in normal use. Nor has any research been done on the effects of breathing GM pollen by farm workers or the neighbouring population.

It has already been shown by other studies that nearly half the caterpillars of Monarch butterflies (not a target species) died when fed on pollen genetically modified with Bt (Bacillus thuringiensis). Some varieties of GM oilseed rape have been found to destroy the ability of bees to detect flower smells. Other studies of GM-fed animals have been described in section 2 above. A major seed dealer in the United States has said that there is evidence that earthworms are dying from the effects of Bt maize. GM genes have also been demonstrated to transfer to soil fungi and bacteria, and the effects of this are not yet known. If, as some experts have warned, the affected fungi and bacteria then behave in abnormal ways and cease or diminish their function in breaking down organic material to make nutrients available to plants, soil could become progressively (and uncontrollably) less fertile; and, as the organisms carrying the transgenes proliferate, the soil over an ever increasing area could become ever less fertile.

The farm-scale trials, while concerned with biodiversity, compare only two methods of chemical agriculture. Many previous studies have shown that wildlife is much more abundant on organic farms than on conventional farms, which use pesticides, herbicides and artificial fertilisers. On organic farms, there are 25% to 220% more birds, one to five times as many invertebrates and five times as many wild plants (with 57% more species) Ironically, the only species studied that was found to be more abundant on conventional farms was aphids. In China, a study found that the biodiversity index of insects in fields of Bt cotton was much lower than on farms growing non-GM cotton.

A particular problem with crops engineered with Bt is that, in its natural form, the Bt toxin is one of the very few control measures allowed in organic farming. If the cultivation of Bt crops becomes widespread, insects would develop resistant strains that would make this valuable control useless to organic farmers.

A great worry with GM crops is that they will contaminate non-GM crops. Transfer of pollen to wild relatives of GM crops has been observed. A profoundly disquieting contamination of the wild varieties of maize in Mexico has occurred, although it grows in remote regions and the cultivation of GM maize is prohibited in Mexico. In North America, some organic farmers have had their certification withdrawn, following contamination from GM crops. GM-free supplies of the major crops that have GM counterparts are becoming difficult to obtain. In the Canadian province of Saskatchewan, almost all organic farming of oilseed rape has had to be abandoned. Oilseed rape with resistance to multiple herbicides has become a major weed in Canada. The experience with this crop has proved to be so calamitous that Canadian farmers are now seeking an injunction against the introduction of GM wheat.

The prescription of zones in which the growing of a particular GM crop would be allowed, or of specified separation distances between GM and non-GM crops of the same species, would not prevent contamination. Insects carry pollen, and bees have been observed to carry pollen at least to a distance of 4.5 km, the maximum distance monitored in the study. Wind can transport viable pollen over hundreds of kilometres, even for a relatively heavy pollen such as that of maize. Theoretical studies show that the amount of pollen deposited is not a simple function of distance from the source; rather, there are ‘fingers’ and islands of high density. Observations reveal the perhaps surprising fact that, beyond a moderate distance from the source, and at least to some unknown distance, the amount of deposited pollen ceases to decline with distance but fluctuates and maintains a significant level.

If GM crops are introduced, contamination will be inevitable – as the government has admitted. The Royal Society has recommended that monitoring of the environment should continue if GM crops are allowed in Britain. Unfortunately, monitoring will not prevent damage; and, if damage does occur, there will be no foreseeable way to remove GM genes from the environment.


4. Actual performance of GM crops

The companies that develop GM seeds claim greater yields, reduced chemical use and general benefits from the growing of their crops. The claims, however, do not reflect realities. While some farmers, in some areas and in some seasons, may gain the claimed benefits, the usual results are disappointing. A major report by the Soil Association on the experiences of North American farmers, based on published work and interviews with farmers, concludes that most of the claimed benefits have not been realised and that GM crops have been a ‘practical and economic disaster’. GM crops have lower yields overall, except for a small increase for yields of Bt maize (but see below), and they have increased reliance on herbicides. A scientist drew attention to how Monsanto obtained the data for its claims about Roundup Ready soya beans: ‘RR soybeans clearly require more herbicides than conventional soybeans, despite claims to the contrary. …Monsanto has manipulated comparative data on RR and conventional soybean herbicide use in ways that fall between misleading and dishonest.’ (Dr Charles Benbrook) The same report, which examined the results of 8,200 soya-bean trials, shows that, on average, these soya beans yield 6% less than conventional varieties and may produce 10% less than top conventional varieties.

In the United States, farmers have sued Monsanto over misrepresentation and failure of its GM cotton. In India, cotton farmers suffered poor yields and poor-quality bolls from GM cotton, despite claims that it would increase yields by 80%. Indian farmers who decided to grow cotton organically, on the other hand, produced a harvest that considerably outperformed both the GM and the conventionally grown non-GM cotton. In Bihar, India, a subsidiary of Monsanto has been banned from selling maize seeds after farmers complained that they had failed to germinate and that much of the winter crop had failed. In Indonesia, Bt cotton was found to yield less than the popular, non-GM variety. In China, Bt cotton actually seems to be encouraging pests and is harming natural enemies of pests.

Another major crop being genetically engineered is oilseed rape. The variety in the UK farm-scale trials (produced by Aventis, now Bayer CropScience) was found to have lower yields than non-GM rape and to be more variable. A study also found that, in spite of being engineered to be resistant to Aventis’s own herbicide, the small decrease in losses resulting from the application of the herbicide failed to outweigh its extra cost.


5. Economic consequences of GM crops

Increasingly, a small number of large biotechnology companies has gained control of the seed market. In some places, they have driven out competition, so that farmers are no longer able to buy non-GM seeds. In North America, even in places where the companies do not prevent the sale of non-GM seed, GM-free seeds may no longer be obtainable because of widespread contamination. As noted in section 3 above, parts of Canada are now so polluted with GM oilseed rape that organic farming of this crop is no longer a viable option.

Farmers and economic analysts report that GM maize and soya beans have been less profitable for farmers than non-GM varieties over the six years that these crops have been grown commercially in North America. Added to the higher cost of the patented seeds is the cost of a licence fee. New seeds must be purchased annually, as farmers are forbidden by their contracts with the seed developers to save seeds.

Exports of maize from the United States to the EU countries have been dropping catastrophically: between 1996 and 2001, exports fell by 99.4%. Canadian sales of oilseed rape and honey have similarly plummeted. Huge economic losses have resulted for North American farmers as a result of their inability to sell their GM-contaminated crops to Europe and other sensitive countries. Consumers in the United Kingdom have forced supermarkets to avoid GM ingredients in products of their own brand. However, unlabelled GM derivatives such as oils and beet sugar are still being sold, and some GM crops are being disposed of as animal feed in this country. Resistance to GM food and GM animal feed by consumers around the world is increasing, including in the United States. In the face of the continuing moratorium on GM crops by the EU countries, the United States has now taken the EU to the World Trade Organisation in an attempt to force acceptance.

Bt cotton has its own economic shortfalls. A major factor in agriculture is availability of water, and results from India show that Bt cotton consumes much more water than do non-Bt hybrids. In addition, Bt cotton has shorter fibres, an undesirable characteristic.

Investors have been warned that Monsanto, the world leader in GM crops, is not a safe company in which to lodge their money.

Problems for farmers, and ultimately for everyone else, are compounded by the current lack of legislation concerning damage that might result from the growing of GM crops. Attempts to introduce legislation that would hold the seed companies responsible have been opposed by the companies and have been unsuccessful.

Organic and conventional farmers in North America, however, have come to realise very well the consequences of having any GM plants on their land, regardless of how innocently they may have arrived there. Seed developers send out inspectors to discover whether any farms contain GM plants and also inspect grains at the time of delivery to stores and mills. Punitive, even bankrupting, fines are imposed if unlicensed GM plants or grains are found. It is of no consequence if the GM seeds arrived on the wind or by other non-deliberate means: the company and the law hold the farmer responsible for ensuring that unpaid-for GM plants do not grow on his land. He has, of course, no ready means of determining whether a particular plant is a GM variety. It is therefore financially safer for a farmer to continue paying for expensive GM seeds and to continue using more chemicals to grow the GM crops, even though they produce lower yields. This strategy avoids the ruinous legal costs the farmer could incur by growing a conventional crop contaminated by a GM one. (Michael Hart)

An American farmer, Corky Jones. who came to Britain to warn against GM crops, explained how they were introduced to the United States. They were presented simply as very promising new varieties, and the revolutionary nature of the new seeds was not disclosed. Once the farmers were growing the new crops, and experiencing increasing difficulties from one year to the next, they found themselves unable to turn back to the old varieties. Some of the past season’s GM seeds would inevitably germinate as ‘volunteers’ amongst their current crop, making them liable to punitive action by the seed company, as noted above. In addition, there is uncertainty as to whether the soils would be considered to be contaminated by the previous GM crop.

Economically, GM crops have proved in most cases to be disadvantageous, if not downright disastrous.


6. Motivation of GM companies

Large seed developers like Monsanto manufactured herbicides before the advent of genetic engineering. When gene technology advanced to the point of permitting transfer of genes from one species to another, these companies saw an opportunity to introduce seeds that are engineered to withstand their own brand of herbicides, while adjacent weeds are killed. Crops with widespread use were particularly targeted.

At the time when he was Monsanto’s chairman, Bob Shapiro said,: ‘It is truly easy to make a great deal of money dealing with very primary needs: food, shelter, clothing.’ In 1996, Robert Fraley, then the President of Monsanto’s Ceregen Division, explained why the company was taking over scores of plant-breeding institutes and smaller biotechnology firms: ‘What you are seeing is not just a consolidation of seed companies, it’s really a consolidation of the entire food chain.’ The result of this strategy was that, by 1999, 30% of the world’s seed trade was owned by 10 companies, of which five controlled almost all GM crops.

As mentioned in previous sections, the companies and the US government are attempting to force world-wide adoption of their GM seeds. Monsanto has been extending its international control to include ownership of water, another vital resource

With all their increasing control over seeds and their drive to push aside obstacles hindering rapid spread of their products, the companies have steadfastly refused to accept responsibility for any harm that might arise as a result of growing GM crops.

GM companies are attempting to play upon the consciences of Europeans by insisting that their opposition to GM food will prevent the development of GM crops that, with their claimed high yields, are necessary to save the world from hunger. But it is poverty and unequal distribution of food that causes hunger, sometimes in countries that hoard a surplus of food. Moreover, ecologically friendly methods of agriculture, using ordinary seeds, can rival the yields of chemical farming whether or not the latter farming method uses GM seeds. GM companies are also creating products like rice engineered to contain vitamin A and claiming that this will prevent blindness from vitamin-A deficiency in less developed countries. They neglect to say that it is the very type of agriculture for which most GM crops are designed that has brought about the widespread emergence of nutritional deficiencies. Large-scale chemical farming of a single crop has replaced small family farms that, without chemicals, used to produce a great diversity of nutritious crops. Even the ‘weeds’ growing between the planted crops produced vitamin A and other nutrients, in addition to providing medicines and animal feed. (Vandana Shiva)

Companies that develop GM seeds are motivated by the possibility of huge profits if they can gain control over the food chain. They certainly do not have at heart, as they claim, the plight of poor farmers who must subject themselves to heavy debts in order to access GM seeds, and to do so on an annual basis. Nor are the companies dissuaded by repeated poor performance and outright failures of their crops; they relentlessly pursue their aggressive endeavours to spread their technology around the world. Yet, neither amongst affluent populations nor amongst those struggling to survive, has the world any need for a dangerous and inadequately tested technology that has the potential to cause devastation on a global scale in the years to come.


References: Many references have been used in this document, including the following:

Chardon LL Hearing (Transcripts at; search on ‘Chardon’. For chicken and rat studies, see also

Seeds of Doubt, a report by the Soil Association, by Hugh Warwick and Gundula Meziani, September 2002.

Dr Charles Benbrook, Ag BioTech InfoNet Technical Paper (several of these) at

Michael Hart, chairman of Small and Family Farms Alliance, 2003, at

Articles at (especially March, April 2003).

Dr Vandana Shiva, BBC Radio, Reith Lecture, BBC Radio 4, 10 May, 2000


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