Genetically modified foods

Genetic modification is now possible using biotechnology. The genetic material may be altered with methods that do not occur naturally - this is known as ‘genetic engineering’. Selected individual genes are transferred from one organism to another. Traditional breeding can achieve similar effects, but over a much longer time span. However, traditional breeding cannot achieve the same effects using a transferred gene from a non-related species - this is possible with GM foods.

Genetic engineering broadens the scope to modify plants
Genetic modification of food is not new. For centuries, food crops and animals have been altered through selective breeding. While genes can be transferred during selective breeding, the scope for exchanging genetic material is much wider using genetic engineering. In theory, genetic engineering allows genetic material to be transferred between any organism, including between plants and animals. For example, the gene from a fish that lives in very cold seas has been inserted into a strawberry, allowing the fruit to be frost-tolerant. This has not as yet been done for currently available commercial food crops.

Foods that have been modified
Some foods have been modified to make them resistant to insects and viruses and more able to tolerate herbicides. Crops that have been modified for these purposes, with approval from the relevant authorities, in a number of countries, include:

• Maize
• Soybean
• Oilseed rape (canola)
• Chicory
• Squash
• Potato.

• Better quality food
• Higher nutritional yields
• Inexpensive and nutritious food, like carrots with more antioxidants
• Foods with a greater shelf life, like tomatoes that taste better and last longer
• Food with medicinal benefits, such as edible vaccines - for example, bananas with bacterial or rotavirus antigens
• Crops and produce that require less chemical application, such as herbicide resistant canola.

• Toxicity (using similar methods to those used for conventional foods)
• Tendency to provoke any allergic reaction
• Stability of the inserted gene
• Whether there is any nutritional deficit or change in the GM food
• Any other unintended effects of the gene insertion.

• New allergens could be inadvertently created - known allergens could be transferred from traditional foods into GM foods. For instance, during laboratory testing, a gene from the Brazil nut was introduced into soybeans. It was found that people with allergies to Brazil nuts could also be allergic to soybeans that had been genetically modified in this way. No allergic effects have been found with currently approved GM foods.
• Antibiotic resistance may develop - bioengineers sometimes insert a ‘marker’ gene to help them identify whether a new gene has been successfully introduced to the host DNA. One such marker gene is for resistance to particular antibiotics. If genes coded for such resistance enter the food chain and are taken up by human gut microflora, the effectiveness of antibiotics could be reduced and human infectious disease risk increased. Research has shown that the risk is very low; however, there is general agreement that use of these markers should be phased out. Stephen Leeder, ‘Genetically modified foods - food for thought’, MJA www.mja.com.au, John Huppatz and Paula A Fitzgerald, MJA 2000
• Cross-breeding - other risks include the potential for cross-breeding between GM crops and surrounding vegetation, including weeds. This could result in weeds that are resistant to herbicides and would thus require a greater use of herbicides, which could lead to soil and water contamination. The environmental safety aspects of GM crops vary considerably according to local conditions.
• Pesticide resistant insects - the genetic modification of some crops to permanently produce the natural biopesticide Bacillus thuringiensis (Bt) toxin could encourage the evolution of Bt-resistant insects, rendering the spray ineffective. Wherever pesticides are used, insect resistance can occur and good agricultural practice includes strategies to minimise this.
• Biodiversity - growing GM crops on a large scale may also have implications for biodiversity, the balance of wildlife and the environment. This is why environmental agencies closely monitor their use.
• Cross-contamination - plants bioengineered to produce pharmaceuticals (medicines etc) may contaminate food crops. Provisions have been introduced in the USA requiring substantial buffer zones, use of separate equipment and a rule that land used for such crops lie fallow for the next year.

• The possible monopolisation of the world food market by large multinational companies that control the distribution of GM seeds.
• Using genes from animals in plant foods may pose ethical, philosophical or religious problems. For example, eating traces of genetic material from pork could be a problem for certain religious groups.
• Animal welfare could be adversely affected. For example, cows given more potent GM growth hormones could suffer from health problems related to growth or metabolism.
• New GM organisms could be patented so that life could become commercial property through patenting.

• ‘Highly refined’ foods where the altered DNA or protein is no longer in the food (for example, oil from modified corn).
• GM food additives or processing aids - unless the new DNA remains in the food to which it is added.
• GM flavours where less than 0.1 per cent is present in the food.
• Food, food ingredients or processing aids where GM ingredients are ‘unintentionally’ present in less than 1.0 per cent.
• Food that is prepared at the point of sale (so takeaway and restaurant food will not have to be labelled).

• Genetic modification has altered the food so that its composition or nutritional value is ‘outside the normal range’ of similar non-GM goods; for example, if GM technology is used to add vitamins.
• Naturally occurring toxins are ‘significantly different’ to similar non-GM foods.
• The food produced using GM technology contains a ‘new factor’, which can cause allergic reactions in some people.
• Genetic modification raises ‘significant ethical, cultural and religious concerns’ regarding the origin of the genetic material used.

• Imported soya from the United States. This is one of the main sources of GM ingredients in food sold in Australia since 1996. The soya has been genetically modified to be resistant to a herbicide. It can be found in a wide range of foods, such as chocolates, potato chips, margarine, mayonnaise, biscuits and bread. Cottonseed oil made from GM cotton (resistant to a pesticide) is also used in Australia. It is used for frying by the food industry, and in mayonnaise and salad dressings.
• Imported GM corn is mainly used as cattle feed at present and has not been approved for farming in Australia. However, GM corn may have entered the Australian market through imported foods like breakfast cereal, bread, corn chips and gravy mixes; if so, it is now required to be labelled.
• Other GM foods available overseas that may be ingredients in foods imported to Australia include potatoes, canola oil, sugar beet, yeast, cauliflower and coffee.

• Food Standards Australia New Zealand Tel. (02) 6271 2222
• Gene Technology Information Service Tel. 1800 631 276

• There are potential benefits, risks and ethical concerns regarding GM foods that are still being researched and debated.
• The health risks associated with consuming GM foods or ingredients have not been unequivocally established.
• There is no current evidence that suggests that GM foods are likely to be harmful to health.
• GM foods sold in Australia, or foods containing GM ingredients, are required by law to be labelled.

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