Too many unknowns in the manufacture and use of GM foods
Canberra Times, 28 July 2008
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In her guest column in this space on July 14, Paula Mathewson of CropLife put forward the genetically modified crop industry's view of GM food. Unfortunately, she left out some critical facts.
First, most GM foods come from GM crops. To make these crops, genetic engineers insert bits of DNA from animals, plants, bacteria and/or viruses into the food plants that we eat. While the GM crop industry boasts about how accurate the process is, the reality is rather different.
A classic insertion method is to actually fire the DNA into the plant using a modified shotgun. As the inserts land randomly, they can interfere with the plant's normal genetic functioning, and may cause a previously unknown substance to be made.
To date, almost all GM plants have been designed to make a new protein that makes the plant able to survive herbicide spraying or to make its own insecticide (which we then eat), and not to benefit consumers.
Like the GM industry, Paula likes how our food regulator regulates GM food. What she
hasn't told you is that the regulator does not do any safety experiments of its own, but only does a paper-based safety assessment, based largely on what the GM crop company decides to tell it. It also does not require any animal or human studies to be done at all before it approves a GM crop as safe.
If any animal studies are actually done, they are almost always done by the GM company that wants to profit from the crop and not by independent researchers. This is like accepting the safety statements made by tobacco companies without requiring independent studies.
Furthermore, these animal studies generally just involve feeding only the new protein that the plant is designed to make as a single oral dose and measuring how many animals die within seven to 14 days.
There are serious problems with this method.
First, the actual protein tested does not come from the GM plant that we eat but from a GM bacterium that we don't eat. Our regulator simply assumes that the protein is the same when it may not be.
Also, it assumes that the plant will only make that substance and nothing else. It also assumes that any animal that is not actually dead must be healthy and will stay that way, when it may in fact be seriously ill.
If feeding studies of actual GM plant material are done, they are usually completed within only four weeks and animal production measures such as meat production are usually measured rather than matters relevant to human health, for example organ
health. Allergy is only assessed using a paper-based method, not by animal studies. Proteins with similarity to known allergic substances have been passed as safe. Reproductive effects are not measured. Study periods are not long enough to allow cancers to develop. Now consider that we will be eating these crops for generations.
Is there evidence of harm from eating GM crops? Yes, mostly from independent researchers using animal models. Effects have been found on the liver, kidney, pancreas, testes, digestive system, respiratory system, immune function (including allergy) and reproduction.
Are any of these occurring in people? We simply don't know. There have been no studies into whether any of the millions of people who have been hospitalised or died since GM crops were introduced got ill due to eating these crops.
Our food regulator has allowed 55 different GM crop varieties into the Australian food supply, mostly corn, soy, canola and cotton. They are likely to be present in much of our daily diet, including fried and baked goods, such as soy in bread and processed food, cottonseed oil in chips and canola in margarine. Refined products like oil are exempt from labelling, as are meat, milk, cheese and eggs from animals that have eaten GM feed.
Why? Because our food regulator believes that they do not contain any DNA or protein from the GM crop. Scientific studies show otherwise. Meals from restaurants and take-aways do not require labelling. Moreover, the labelling laws are not policed.
Finally, Paula uses one survey to "show" that people have no concerns about eating GM foods. Unfortunately, she didn't mention all the surveys by bodies such as Swinburne University, Roy Morgan Research and Biotechnology Australia that show the opposite. Polling also shows that 92 per cent of Australians want all GM food labelled.
Of course, the GM crop industry doesn't want this and continues to vigorously oppose it. Labelling allows for consumer choice, traceability, easier investigations into the effects of GM crops on human health and easier legal action.
*Dr Carman is director of the Institute of Health and Environmental Research