Scientists have voiced concern that such disruptions could lead to unexpected toxins being produced, or to changes in the levels of nutrients and naturally occurring toxins. There are examples of genetic modification changing plants in entirely unexpected ways. For example, when researchers in Germany tried to boost the starch content of potatoes using genes from yeast and bacteria, they found that the starch content actually fell and other, unexpected, compounds were produced3.
Genetic engineering is an unpredictable and imprecise process. By inserting ‘alien’ genes from organisms which have never been eaten as food, new proteins are introduced into the animal and human food chains. There is concern that these could cause allergic reactions or other negative health effects. In other words, they are a potential “poison,” as was stated by the Zambian president Levy Mwanawasa4.
The safety testing of GM foods is based on the concept of ‘substantial equivalence’. This is the idea that if a GM food can be shown to be ‘substantially’ the same as a non GM food then it is considered to be safe. It was developed because of the difficulties and cost of conducting traditional safety tests (like those used for new drugs) on GM foods. But it has been severely criticised by some scientists because it is not clear what level of similarity makes something ‘substantially’ equivalent5.
Many GM crops contain genes which provide resistance to commonly used antibiotics such as ampicillin. There is concern that these genes could be passed from food to bacteria in the guts of humans and animals. In the Netherlands, researchers used a model of a human gut to look at what would happen to GM food after it is eaten. They predicted that 6% of the genes from GM tomatoes would survive digestion and considered that the genes could survive for long enough for bacteria to pick them up. In 2002, research published by the Food Standards Agency showed this happening for the first time, when GM genes were found to have been picked up by gut bacteria of human volunteers6. Therefore this concern of genes ‘jumping’ the species barrier is a potentially disastrous one, because it could lead to mutations in organisms, such as bacteria, that could stop medicines such as penicillin working against them.
As well as harmful effects to humans, genetically modified crops are also affecting wildlife. Wildlife in UK farmland is already in severe decline because of intensive, chemical farming. Plants which were considered to be arable weeds 40 years ago are now listed as rare or scarce and some are endangered. Similarly more than 20 bird species including the tree sparrow and song thrush have shown drastic declines in numbers since the 1970s 7. There is widespread concern that the use of GM herbicide tolerant crops could make this worse.
To add to the list of concerns for farmers and the public when growing GM crops, is the risk of contamination. One of the main difficulties which farmers encounter when growing GM crops is that there is no way to contain pollen movement. In the case of oilseed rape, researchers have found that its pollen can travel up to 4km and can escape from fields even when they are surrounded by barrier crops to prevent this. The Government has separation distance requirements between GM and non-GM crops. These only require farmers to leave a distance of 50-200m between GM and non-GM oilseed rape and 50-200m for maize.8. But evidence shows that this is clearly not enough to prevent GM contamination. There have already been several serious incidents, despite the fact that GM crops are only grown by a minority of farmers worldwide.
A myth associated with GM Crops, is that they are necessary to feed the world’s growing population in the coming century by increasing yields and fighting crop diseases. However, many people in the world are suffering from malnutrition and hunger because they cannot afford to buy food, not because it is unavailable. Complex social, political and economic forces affect how people have access to land, money and resources.
It is these forces, much more than the level of food production which determine who gets to eat, and who does not. It is not just a simple case of there being more people, so more food should be grown. There is more than enough food to feed everyone very well at the moment, yet hundreds of millions of people go hungry and nearly two billion are malnourished. For example, in 1998 it is estimated that 36 million people, including 14 million children, were hungry or on the brink of hunger in the USA9, one of the richest countries in the world!
In conclusion, I feel that there are too many concerns and disadvantages associated with GM crops, to make them a viable option for food. I feel that although they do have their benefits, this is heavily overshadowed by their disadvantages, and subsequently alternative and safer methods should be introduced to replace GM crops.
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BIBLIOGRAPHY/REFERENCES:
- Book: GM CROPS – The Scientists Speak
By Brian John Ford.
ISBN: 0954359534
- Science Today – Pg 289
Titled: Reaping the Plant Gene Harvest. By T. Gura
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New Scientist – 30th October 2002
Titled: “Zambia Bans GM Food Aid.” By Andy Coghlan
- Nutritional Therapy Today 7 (1997) – Pg5
Titled: “Substantial Equivalence – A license to kill?” By Antoniou M.
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The Daily Telegraph – 19th February 1999
Titled: “Report raises fear of faster decline in farm wildlife.” By Charles Glover
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The Sunday Express – 14th November 1999
By Roger Highfield
- A New Introduction to Biology.
By Bill Indge, Martin Rowland, Margaret Baker
