GM foods are genetically modified using biotechnology. Common GM foods include maize, soybeans, oilseed rape (canola), chicory, squash, potatoes, pineapples and strawberries. GM foods are designed for greater resistance to pests and viruses, higher nutritional value and longer shelf life. However, their safety, potential risks and ethical concerns are still being debated. Laws to regulate labelling of GM foods vary.
Foods genetically modified using biotechnology are known as GM foods. Genetic material is altered using non-traditional, laboratory-based methods; this is known as genetic engineering. Individual genes with specific desirable traits are transferred from one organism to another.
Traditional breeding can achieve similar effects, but works over a much longer time span and is not as targeted as GM. In addition, traditional breeding cannot transfer genes from unrelated species as is possible with GM foods.
Genetic modification of plants and animals
Genetic modification of food is not new. Humans have been altering food crops and animals through selective breeding for many centuries. However, 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 two organisms, 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. However, this has not yet been done for currently available commercial food crops.
Concerns about climate change may lead to increased development and use of drought-tolerant GM food crops.
Existing GM crops
Some foods and fibre crops have been modified to make them resistant to insects and viruses and more able to tolerate herbicides. The major crops that have been modified for these purposes, with approval from the relevant authorities, are:
- Maize (corn)
- Oilseed rape (canola)
GM products in food
Modified genes are being used in whole foods such as wheat, soybeans, maize and tomatoes. These GM whole foods are not presently available in Australia. GM food ingredients are, however, present in some Australian foods. For example, soy flour in bread may have come from imported GM soybeans.
Modified genes may have been used in an early stage of the food chain, but may or may not be present in the end product. Nevertheless, gene products – for example, phytochemicals (plant chemicals that contain compounds which may prevent disease) – may remain in the food chain. The implications for human health are unknown.
Organic foods are not genetically modified
Foods certified as organic or biodynamic should not contain any GM ingredients, according to industry guidelines.
Benefits of GM foods
Inexpensive, safe and nutritious foods are needed to feed the world’s growing population. Genetic modification may provide:
- Sturdy plants able to withstand weather extremes
- Drought-tolerant and salt-tolerant crops
- Better-quality food crops
- Higher nutritional yields
- Inexpensive and nutritious food, such as carrots with more antioxidants
- Foods with a longer shelf life, like tomatoes that taste better and last longer
- Food with medicinal (nutraceutical) benefits, such as edible vaccines – for example, bananas with bacterial or rotavirus antigens
- Disease- and insect-resistant crops that require less pesticide and herbicide – for example, GM canola.
Environmental benefits of GM foods
GM advocates argue that GM foods are better for the environment. By using GM crops that are resistant to attack by pests or disease, farmers can reduce their use of pesticides and herbicides and the residual levels of these chemicals in the environment. However, development of resistance can undermine and even reverse this benefit.
GM and nutritional enhancement
Genetic engineering can be used to increase amounts of particular nutrients (like vitamins) in food crops. Research into this technique, sometimes called nutritional enhancement, is now at an advanced stage.
GM golden rice is a white rice crop modified by the insertion of the vitamin A gene from a daffodil plant. This changes the colour and the vitamin level of the rice and is of benefit in countries where vitamin A deficiency is prevalent.
GM researchers are focusing on major health problems like iron deficiency. The removal of the proteins that cause allergies from nuts (such as peanuts and brazil nuts) is also being studied.
The risks of GM crops
Concerns about genetic modification of food raised by scientists, community groups and members of the public include:
- 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 and so the project was ceased. 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 antibiotic 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.
- Cross-breeding – GM crops can cross-breed with surrounding vegetation, including weeds, transferring undesired characteristics. The introduction of glyphosate-resistant soybeans in 1996 has produced glyphosate-tolerant weeds that have driven even greater use of herbicides.
- Pesticide-resistant insects – the genetic modification of some crops to produce the natural biopesticide Bacillus thuringiensis (Bt) toxin could encourage the evolution of Bt-resistant insects, rendering the spray ineffective.
- Biodiversity – growing GM crops on a large scale may affect the balance of wildlife and the environment. Since bees cannot distinguish GM from non-GM crops, GM crops can affect non-GM and organically–farmed crops through cross-pollination.
- Cross-contamination – plants bioengineered to produce pharmaceuticals (such as medicines) may contaminate food crops.
- Health effects – minimal research has been conducted into the potential acute or chronic health risks of using GM foods.
Social and ethical concerns about GM
Concerns about the social and ethical issues surrounding genetic modification include:
- The possible monopolisation of the world food market by large multinational companies that control the distribution of GM seeds
- Concerns related to using genes from animals in plant foods. For example, eating traces of genetic material from pork is problematic for certain religious and cultural 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 itself could become commercial property.
Regulation of GM foods
In Australia, GM foods are regulated by the Food Standards Australia New Zealand (FSANZ) Code under Standard 1.5.2 – Food produced using Gene Technology. GM foods receive individual pre-market safety assessments prior to use in foods for human consumption.
A GM food will only be approved for sale if it is assessed as being safe and as nutritious as its conventional counterparts. The assessment investigates:
- Nutritional content
- 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.
The safety of GM foods is still being debated, as it is impossible to predict all of the potential effects on human health and the environment. Consequently, some public health experts advocate caution, believing that we do not know whether GM foods are safe.
Since December 2002, Australia law has required that food labels must show if food has been genetically modified or contains GM ingredients, or whether GM additives or processing aids remain in the final food product. The label on the package must include the statement ‘genetically modified’ in conjunction with the name of the food or ingredient or processing aid.
GM foods are labelled to help consumers make informed decisions about the food they buy, not for safety reasons. Special labels are not required for:
- ‘Highly refined’ foods that no longer contain the altered DNA or protein (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 constituting less than 0.1 per cent of the food by weight
- Food, food ingredients or processing aids unintentionally containing less than one per cent GM material
- Food prepared at point of sale (takeaway and restaurant food does not have to be labelled).
Labels may be required if:
- 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, high omega-3 soybeans)
- Food contains toxins which are significantly different to those in 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.
GM food on the shelves
Many foods on supermarket shelves contain imported GM ingredients. GM foods have also been approved for production in Australia, including corn, soybeans, potatoes, canola and rice.
Other GM foods are still undergoing field trials approved by the Office of the Gene Technology Regulator, although the moratorium by state governments (lifted in Victoria and NSW in early 2008) stopped some trials. Imported food products are subject to the same regulations as domestically manufactured foods.
Around 20 GM foods, additives, flavourings, growth hormone (bovine somatotropin) and enzymes (like rennet, used to make cheese) are currently approved in Europe. More than 40 GM foods are approved for sale in the USA.
The main sources of GM foods in Australia are:
- Soya imported from the United States – 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 – this oil, made from cotton resistant to a pesticide, is used in Australia for frying (by the food industry) and in mayonnaise and salad dressings
- Imported GM corn – this 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
- GM ingredients in imported foods – including GM potatoes, canola oil, rice, sugar beet, yeast, cauliflower and coffee.
Finding GM-free food
Due to consumer demand, some food manufacturers in Australia provide GM-free food. These products may be labelled as GM free, and non-GM claims such as ‘contains no genetically modified ingredients’ are made by food manufacturers.
Enquiries about GM matters people can be directed to the Office of the Gene Technology Regulator.
Where to get help
- Food Standards Australia New Zealand (FSANZ) Tel. (02) 6271 2222
- TechNyou (formerly the Gene and NanoTechnology Information Service) Tel. 1800 631 276
- Office of the Gene Technology Regulator Tel. 1800 181 030
Things to remember
- The benefits, risks and ethical concerns regarding GM foods are still being researched and debated.
- The health risks associated with consuming GM foods or ingredients have not been unequivocally established.
- No current evidence suggests that GM foods are harmful to health.
- GM foods sold in Australia, or foods containing GM ingredients, are required to be labelled.
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Last reviewed: July 2011
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