GM Foods - What Are The Issues?

This post is designed to aid teachers and pupils in a classroom discussion on the issues around GM Foods. This article first appeared in the November issue of Science Spin and was written by Frog Blogger Humphrey Jones.

GM or “genetically modified” foods are food products that have been produced by plants or animals whose genetic makeup has been altered artificially. Such alteration is called genetic engineering and involves changing an organism’s DNA, usually by introducing a new gene. These changes can result in foods growing more quickly, growing larger, varying in colour or becoming resistant to a certain disease or pest. GM foods have been grown since the 1990’s, mostly in the United States, and are typically plant crops like soya, maize or rapeseed, although some GM foods are produced from animals. The growth of GM crops has proven very controversial amid concerns over their effects on human health. A class discussion on GM foods is a great way to explore the science behind their production, their potential benefits and their harmful effects.

Sexual Reproduction vs. Genetic Engineering
During sexual reproduction, two gametes (sex cells) fuse forming a new organism. This organism is genetically different from its parents (i.e. its DNA is slightly different from both parents), with different characteristics. The changes are random and generally unpredictable. This is generally called cross or selective breeding and has been the principle means of creating new strains of crops or new breeds of food producing animals in agriculture. In some sense, all crops are genetically modified through natural and artificial selection, and by selective breeding and crossing. When we talk about genetically modified organisms (GMOs), however, we mean something more specific: organisms whose genetic makeup has been modified beyond what can be achieved through regular sexual reproduction. For discussion: Is selective breeding natural? Is it ethically right to alter genes in organisms?

How are GM Foods made?
GM foods are produced from GMO’s, organisms whose DNA is altered slightly without sexual reproduction - the changes are not random but specific, and their effects are more predictable. Most GMO’s are produced by introducing a gene sequence from another organism (e.g. a bacteria resistant to a pesticide) into the DNA of a food producing crop (e.g. potato). The result is the newly formed potato has a built in pesticide, therefore not requiring pesticides to be sprayed on the crop during the growing season. For discussion: Is producing GMO’s going against nature? What are the risks? Can these genes be transferred to “natural” crops? Are pesticide resistant crops preferable to crops sprayed with pesticides?

What are the benefits of GM Foods?
There are seemingly lots of advantages in growing GM crops. Disease and pest resistant varieties of crops can be grown without the need to spray fungicides, herbicides or pesticides. Plants can grow more quickly. Crops can get higher yields. Food will remain fresher for longer. Foods can be made more nutritious with added vitamins and minerals. Crops can grow in colder conditions and can become resistant to frost or drought. GM animals can produce higher yields of milk, meat or eggs. GM foods are better for the environment (no pesticide, herbicide or fungicides in ground water and GM pigs produce less “toxic” manure). GM foods can provide food for third world countries. For discussion: Are there more benefits to GM foods? Do the benefits outweigh the concerns?

Are GM Foods dangerous?
There are many concerns over the consumption and growth of GM crops. Many are concerned for the effects on human health, specifically the possibility of allergic reactions, transfer of antibiotic resistance and the unknown effects they might have on the human body. There are environmental effects – these new crops may transfer their genes to natural varieties of the same plant, reduce biodiversity, effect farm animals that may eat them or have a harmful effect on soil microbes. There are also social concerns too – GM varieties are the intellectual property of large multinational companies who could dominate the world’s food production and developing countries could become dependent on first world nations that produce these GM crops. Also, GM foods do not need to be labelled in some countries (principally the United States), meaning consumers doesn’t know they are buying these products. Is this ethically right? Mandatory labelling is required in the European Union (EU) on all products made using GMO’s. There are also ethical issues – will GM animals experience undue stress during their lifetime? For discussion: What are the other concerns over GM foods? Do the concerns outweigh the benefits? What effect will the growth of GM foods have on third world countries? Are GM foods preferred to foods treated with potentially harmful pesticides, herbicides or fungicides? What are ethical issues around the production of GM animals?

GM Crops and the European Union
EU legislation on GMO’s has been in place since the early 1990’s specifically aimed at protecting human health, protecting the environment and ensuring the “free movement of safe and healthy genetically modified products in the European Union”. Additional pieces of legislation have been introduced over the last 20 years which have further regulated the production and sale of GM foods in the EU. In March of this year, the EU Commission allowed genetically modified potato varieties (resistant to blight) to be grown in some EU countries for the first time. However, Europe remains divided on the issue, with many countries unhappy with the reassurances given on GM food’s safety. The EU will most like now allow each member state decide for themselves on the growth of GM crops. But would Irish farmers be prepared to grow GM crops on their farms? Well, in a recent Macra na Feirme survey, 54.9% of Irish farmers said they would consider growing GM crops on their farms, highlighting that young Irish farmers are open to exploring new technologies. For discussion: Should the EU Commission allow GM crops be grown in the EU? Should the EU allow each member state decide for themselves? Should Irish farmers grow GM foods on Irish soil?

GM foods clearly have the potential to improve world agriculture in the future, eliminate the need for harmful pesticides, fungicides and herbicides and potentially improve the nutritional value and shelf life of our fruit and vegetables. But many concerns still remain around the effects of GM foods on human health, ethics, safety, society and transparency. Until these concerns are alleviated, their full potential may not be realised. A discussion on GM foods can cross various subject areas including agricultural science, biology, CSPE, geography, economics and history and can be an excellent way to further pupils understanding on the science behind the technology and, broadly, around the ethical responsibility of science.


Teasy said…
As mentioned there are still many potentially treacherous effects of GM foods to be covered. Even though the potential benefits are obvious to everyone it remains a potentially very slippery slope we are on with GM foods. There are probably very good reasons why millions of years of evolution has NOT developed organisms like the ones we are now developing. The reality of the matter is that we have very little idea what the long term consequences of these organisms in our environment may be. Common sense should tell us that when we mess with nature then we are playing a very dangerous game - there is another discussion about this here
Iamreddave said…
"Sexual Reproduction vs. Genetic Engineering" many of the crops we have now have significant mutations from deliberate gamma irradiation in the 50's and 60's. Golden promise barley beloved by organic breweries for being old fashioned for example. So the choice is not Natural versus GM but Natural vs radiated vs GM.

'Common sense should tell us that when we mess with nature then we are playing a very dangerous game' it does, but the precautionary principle would presumably apply to wheat 5000 years ago when the genomes from three organisms were stuck together in a very unnatural way?

Or is it only the latest method of manipulating genomes that is unnatural the previous ones are fine?

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