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You are in GM Crops and Food → Introductory Guide → Food Safety

Food Safety

Is GM food safe to eat? Some argue that GM foods are tested more thoroughly than any other foods, while others believe that we have not tested them enough so would not know if there are problems. Although GM foods have been eaten in some countries for six years, there has been no monitoring so hard evidence about their safety is in short supply.

The first specific regulations for safety testing of GM foods became law in Europein 1997. These were revisedin 2003. To read more about how GM food is assessed for food saftey read the regulations section of our website

There are 4 main areas of food safety concern:

• The genetic modification itself may make the plant toxic when eaten.
• The new GM characteristic may cause allergies.
• If antibiotic resistance genes are used, they may increase problems with drug resistant diseases.
• The GM process may have unintended effects on the plant, which may affect food safety.

Toxicity - When a crop is changed to make it resistant to insects or tolerant of weedkillers, it has to make new compounds to carry out these functions. If people have not eaten such compounds before, they will need to be safety tested. Some toxicity testing is carried out using laboratory animals, which may detect very rapid effects but may not identify longer-term, more subtle health effects.

Allergies - The new compounds produced in the GM food may cause an allergic reaction. Food allergies are on the increase as we eat more varied diets with new ingredients. It will be possible to test for allergenicity if the GM genes come from something such as peanuts, which are known to cause allergies in some people, but with new sources it will be much harder. When a new food is introduced, it takes 5-6 years before allergies are recognised.

Unintended effects - GM is not a precise technique. There is no control over where genes are inserted among the plant's own genes. Many copies or fragments of genes can be included and the gene may even be inserted backwards. There is plenty of potential for unexpected outcomes if normal genes are disrupted or the foreign gene does not function properly. These may affect the chemical composition of the crop and the safety of the food derived from it. Until recently, GM food safety testing ignored the potential for unintended effects, and techniques to screen GM foods for 'surprise' effects are still in the development stage.

Antibiotic resistance - Antibiotic resistance genes are used as 'markers' in GM crops to indicate whether the genetic modification has been successful. The GM process is inefficient and only a small number of cells incorporate the foreign genes. Therefore, an antibiotic resistance gene is included and, if the genetic modification is successful, the plant cell will grow in the presence of the antibiotic - if not, it will die. If these genes are transferred to disease-causing organisms, they may compromise antibiotic treatment. The antibiotic marker genes have no function in the plant and could be removed, but this costs more. The British Medical Association has called for a ban on the use of antibiotic resistance marker genes.

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