Controverisal Issues

1. 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.

2. 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.

3. 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.

4. 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.

5. 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.

6. 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.

Ethical concerns

Concerns about genetic modification include:

• 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.

GM labelling and the law

Since December 2002, the law in Australia states that food labels must show if food has been genetically modified or contains genetically modified ingredients, or whether GM additives or processing aids remain in the final food.

Special labels are not required for:

• ‘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).

Labels may be required where:

• 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.

GM food on the shelves

There are around 20 GM foods, additives, flavourings, growth hormone (bovine somatotropin) and enzymes (like rennet, used to make cheese) currently approved in Europe. In the USA, there are more than 40 approved GM foods.

The main sources of GM foods in Australia include:

• 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.

Reference: "Genetically Modified Foods." Better Health Channel. Nov. 2006. Deakin University- Faculty of Health and Behavioural Sciences. 27 June 2008 .