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Busting the GM myths: a view from Greenpeace

The Conversation recently published an article looking at the myths about genetic modification. This article is a rejoinder to that piece, and a contribution to the ongoing debate about whether there is…

Canola is one of two GM crops approved in Australia. Ngarkat

The Conversation recently published an article looking at the myths about genetic modification. This article is a rejoinder to that piece, and a contribution to the ongoing debate about whether there is any safe way to genetically modify our food.

GM is crude science

Genetic engineering (or genetic modification) inserts DNA (or genes) into the genome of a plant. The genomes of plants and animals are controlled by a complex regulatory network that controls gene expression (the production of proteins). Genetic engineering does not take account of this.

The inserted GM genes operate outside this regulatory network. Because the exact nature of this network is poorly understood, it is not possible to predict the interaction of the inserted genes with the plant’s own genome when the genes are being expressed.

Inserting DNA can cause additional fragments to be inserted and can also delete and rearrange the plant’s own DNA.

Unexpected and unknown fragments of genetic material have been found in commercial GM crops¹ (for example, Roundup Ready soya² and insect resistant maize³, MON810).

As a consequence, GM crops could produce unintended novel proteins, or altered plant proteins. Because most allergens are proteins, this raises concerns about these crops' potential to cause allergies.

As Richard Richards points out, genetic engineering is not a good way to develop plant varieties with complex traits (such as drought resistance).

This doesn’t mean we can’t develop these types of varieties. Other biotechnologies, such as marker assisted selection (an advanced form of breeding) can be used to develop new varieties, such as drought-resistant rice and wheat.

These technologies use our knowledge of how plant genomes function, but do not result in the deliberate release of a GM plant. Plants developed using this method are already in farmer’s fields.

GM crops do not increase yield and will not solve hunger

The United Nations/World Bank assessment of agriculture was performed by 400 scientists from over 100 countries. They carefully examined whether GM crops increased yields and could not come to a firm conclusion:

“The pool of evidence of the sustainability and productivity of GMOs in different settings is relatively anecdotal, and the findings from different contexts are variable, allowing proponents and critics to hold entrenched positions about their present and potential value.

“Some regions report increases in some crops and positive financial returns have been reported for GM cotton in studies including South Africa, Argentina, China, India and Mexico.

“In contrast, the US and Argentina may have slight yield declines in soybeans, and also for maize in the US⁴”.

The evidence is clear that GM plants are unlikely to play any effective role in increasing food security. In fact, the expense and risk of GM crops could actually decrease food security. GM seeds are subject to patent claims which will indirectly increase the price of food; this will not alleviate poverty or hunger and will pose a threat to food sovereignty.

As the UN Agriculture Assessment states: “In developing countries especially, instruments such as patents may drive up costs, restrict experimentation by the individual farmer or public researcher while also potentially undermining local practices that enhance food security and economic sustainability”⁵.

Food insecurity is related to industrial farming, bad harvests related to climate change, unjust distribution of food, changes in consumption patterns, financial speculation on agricultural commodities and the rush for agrofuels.

This problem is not restricted to the Global South. In 2005, one in 20 Victorians experienced food insecurity.

Solutions to hunger and malnutrition are not easy. But supporting farmers and farm workers in eco-agriculture systems that minimise dependency on external inputs, such as artificial fertilisers and pesticides, is a major option to fight hunger and improve food security worldwide⁶.

GM crops pose risks to the environment

Most GM crops are either insect-resistant (that is, produce their own pesticide), herbicide-tolerant or sometimes both.

The environmental risks of GM insect-resistant crops have been documented in a review of the scientific literature⁷ and are summarised briefly here. Many GM insect-resistant crops produce the same or a similar toxin to GM maize so many of the concerns can, in general, be extrapolated to other GM insect-resistant crops.

GM insect resistant crops are designed to kill specific pests, by exuding a toxin called Bacillus thuringiensis (or Bt).

This Bt is different from the bacterial sprays used in conventional and organic agriculture: it is less specific to the organisms it can affect. For example, GM insect-resistant crops may be toxic to “non-target” organisms, such as butterflies. Long-term exposure to pollen from GM insect-resistant maize causes a decreased survival rate in monarch butterfly larvae⁸.

GM insect-resistant crops can be toxic to other, beneficial insects which are important in the natural control of maize pests, such as green lacewings.

Studies have shown that other, new pest insects are filling the void left by the absence of the specific insect pests controlled Bt crops target⁹. This leads to the spraying of additional pesticides with additional costs to both farmers and the environment.

GM herbicide-tolerant crops are generally associated with one of two herbicides: glyphosate (sold as Roundup), associated with GM Roundup Ready crops, or glufosinate, associated with GM Liberty Link crops. Both these herbicides raise concerns but, in terms of environmental effects, most studies have focussed on glyphosate (or Roundup).

In the past 10-15 years, many new studies suggest that Monsanto’s Roundup is far less environmentally benign than previously thought. These studies are the subject of a recent review¹⁰ but are summarised briefly here.

There are concerns Roundup (or glyphosate) is toxic to aquatic biodiversity¹¹, such as frog larvae (tadpoles).

Glyphosate applications are associated with nutrient (nitrogen and manganese) deficiencies in GM Roundup Ready soya, thought to be induced by its effects on soil microorganisms¹².

Evolution of weed resistance to Roundup is now well-documented as a serious problem where Roundup Ready crops are grown on a large scale. Increasing amounts of herbicide have to be used to control these weeds, or else additional herbicides have to be used to supplement Roundup. This implies an increased toxic burden on the environment and people.

We do not know if GM foods are safe to eat

Many GM crops end up in food for humans and animals. In Australia, only two GM crops are cultivated – canola and cotton – but many are approved for food imports.

There are two ways in which genetic engineering may affect food safety:

  • Gene disruption or instability may lead to new toxins being produced.
  • The new protein produced by the foreign gene may cause allergies or toxicity.

Because GM crops are prone to unexpected and unpredictable effects, the evaluation of food safety requires looking for unexpected and unpredictable effects. This is extremely difficult, if not impossible. Therefore, all current testing regimes for GM foodstuffs around the world are inadequate.

National inadequacies also exist. A recent report of the Australian Auditor General questioned whether Food Standards Australia New Zealand (FSANZ) gets sufficient information from applicants to be an effective regulator.

The Auditor found that FSANZ has no procedure for ensuring the data provided by corporate applicants is actually correct and complete. They found gaps in supporting data and evidence that some applications were approved¹³, despite these gaps.

In 2005, the development of an Australian GM pea was dramatically stopped because a study found serious health impacts in mice¹⁴. Small changes in the structure of the GM protein were found to unexpectedly cause allergenic reactions in mice.

The incident sent shockwaves around the world. People wanted to know whether this toxicity would have been detected in routine testing to evaluate GM food safety.

As the editor of New Scientist said¹⁵:

“The important question is whether national regulatory authorities would have spotted the allergy. In Australia, where the research was done, the answer is no. Although researchers ended the project voluntarily when they discovered the allergic reactions, the tests they did are not mandatory.”

We simply do not know if GM crops are safe for animal or human consumption.


1) Windels, P. et al. 2001. European Food Research Technology 213:107-112

2) Rang, A. et al 2004. European Food Research Technology 220: 438-443

3) Hernandez, M. et al. 2003. Transgenic Research 12: 179–189

4) IAASTD.pdf). 2009. Agriculture at a Crossroads - Synthesis report.

5) IAASTD.pdf). 2009. Agriculture at a Crossroads - Synthesis report.

6) Nellemann, C. et al.2009. The Environmental Food Crisis.

7) Cotter, J. 2009. GM insect-resistant (Bt) maize in Europe: a growing threat to wildlife and agriculture

8) Dively, Galen P. et al. 2004. Entomological Society of America 33: 1116-25.

9) Wang, S. et al 2008. Int J Biotechnology 10: 113-21.

10) Riley, P. et al. 2011. Herbicide Tolerance and GM Crops.

11) Relyea, Rick A.. 2005. Ecological Applications 15:1118–1124

12) Kremer, R.J. and Means, N.E.. 2009. European Journal of Agronomy 31: 153-161.

13) ANAO. 2010. Food Standards Australia New Zealand.

14) Prescott, Vanessa E. et al. 2005. J. Agric. Food Chem. 53: 9023–9030.

15) Editorial. 2005. New Scientist 2527.

Greenpeace campaigns to prevent the deliberate release of genetically modified (GM) or genetically engineered (GE) organisms into the environment. GM organisms (plants, animals, micro-organisms) are living organisms that can multiply and cross-breed and pose a threat of irreversible damage to biodiversity and ecosystems. The safety, long term, of GM food for humans and feed for animals is unknown.

Dr Cotter is visiting Australia from October 16-26 to highlight concerns over the safety of GM wheat.

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20 Comments sorted by

  1. Mark Groeneveld

    logged in via Facebook

    "As a consequence, GM crops could produce unintended novel proteins, or altered plant proteins. Because most allergens are proteins, this raises concerns about these crops' potential to cause allergies."

    The conclusion does not logically follow, just because most allergens are proteins does not mean that one of these unintended or altered proteins has a significant probability of being an allergen. Put another way, there may be a thousand allergens and 10 million proteins (not accurate numbers, but useful for demonstration). Most of the allergens are proteins, but a random protein has a very very small chance of being an allergen. You have not demonstrated that this chance is high enough to cause concern.

  2. Daryl Holland

    logged in via Twitter

    It is also illogical to state that there is poor quality evidence for or against an overall benefit in yields from current GM crops and then go on to say

    "The evidence is clear that GM plants are unlikely to play any effective role in increasing food security."

    It also appears that the author is suggesting that novel proteins are never produced during traditional cross-breeding or selection.

    Also, a minor point, but Bacillus thuringiensis is not a toxin, it is a bacterium and is not exuded or produced by any crop. The Bt toxin is produced by crops, yes, but not Bt itself.

  3. Anna Alvsdotter

    logged in via Facebook

    Oh but there is very good evidence supporting organic farming over what now, sadly, is called 'conventional' farming. A 30-year, side-by-side trial of these two farming methods concludes that organic farming outperforms 'conventional' farming in every measure; crop resilience, yield, farmers’ income, sustainability, energy use, soil health, employment and food security.

    "With results like these, why does conventional wisdom favour chemical farming? Vested interests. Organic farming keeps more money on the farm and in rural communities and out of the pockets of chemical companies. As the major funders of research centres and universities, and major advertisers in the farm media, they effectively buy a pro-chemical bias."

    1. Tyson Adams

      Scientist and author

      In reply to Anna Alvsdotter

      Actually Anna, organic farming has been shown to be inferior in just about every respect. Why else would the vast majority of the world's farmers be using conventional practices?

      This article, as I have come to expect from anti-GM and Greenpeace activists, is light on actual science. It is especially fond of citing research out of context, such as the point Bernie raised below about the Monarch Butterfly. I'm quite sick of the specious and fraudulent way these groups wish to use science to further their little agenda.

      It is likely that we will have 9.3 billion mouths to feed by 2050. We can either use 1950s agriculture (organic) which was able to support 2.5 billion people, or we can use every modern tool we have to grow food.

      BSc, MSc, PhD
      Plant Science

  4. Bernie Masters

    environmental consultant at FIA Technology Pty Ltd, B K Masters and Associates

    In any science-based debate which also relies on emotion to garner support, it's important that the science be clearly enunciated so that people can make their own decisions about whether, in this case, they should be pro- or anti-GM. To give one example where Cotter's article relies more on emotion than science, I refer you to her statement that "Long-term exposure to pollen from GM insect-resistant maize causes a decreased survival rate in monarch butterfly larvae⁸."

    In isolation, the statement…

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    1. Hamish Jackson


      In reply to Bernie Masters

      I agree with you Bernie regarding Cotter's statement regarding Monarch butterflies, it is annoying that she distorted the evidence around this issue. Thanks also to Daryl, but I'm not sure these points taken together undermine the whole article as implied by Bernie. Many of her statements appear to be in line with her cited references (eg 5, 6 , 11, 15). Indeed, was is not a more rigorous piece than the original Five Myths article, which I found to be suspiciously rosy about the GM issues?

  5. Ross Barnard

    Professor; Biotechnology Program Director at University of Queensland

    More of the old either/or arguments..... Can't we just use what works in a particular place, for a particular crop, whether it's conventional, marker assisted selection, mutagenesis and selection, or genetic modification and selection?? Then TEST the foods for their nutritional and chemical content and allergenicity, irrespective of the method by which they were produced. We had better watch out, though. If we test too carefully we might have to ban some foods we love (irrespective of their "organic" or "non-organic" means of production) because of the natural toxins they contain.

  6. Davoe McNamee

    logged in via email

    The climate change deniers have an evil twin in Greenpeace. This organisation is against science (when they don't like it) and recently destroyed a test crop in controlled conditions for no good reason. If you want to see their unscientific attitude, look no further than the quote from Lord Melchett in the house of Lords.

    Lord Melchett: 'It is a permanent and definite and complete opposition based on a view that there will always be major uncertainties. It is the nature of the technology, indeed…

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  7. Sue Chapman


    I'm wondering why the author says:
    "In Australia, only two GM crops are cultivated – canola and cotton – but many are approved for food imports."
    when both links in that appear to point to a list of various other crops approved and perhaps growing, no mention of importing. I'd like clear identification on foods we buy, not just "GMO" but whether the mod contains a new pesticide etc.

  8. wilma western

    logged in via email

    Isn't it amazing how the anti-GM crops people never mention the terrible hazards of medical biotech and manipulating genes of bacteria etc for treatment purposes? According to them , gloom and doom threatens the majority of developed country farmers who are just too stupid to understand that industrial farming ( whatever that is) is no good either for profits or productivity. Ross Barnard is right when he urges us to look at what works rather than taking up ideological positions, and it's good to see Bernie going to the trouble of showing up the misuse of the monarch butterfly research. Glyphosate has been used for decades by farmers for non- GM cropping .The image of glyphosate sprayed on a cropping paddock in the Wimmera killing off the tadpoles living there was pretty irresistible. Properly used with GM crops ,less glyphosate can be used therefore reducing problems of chemical cost and resistance....words from a retired farmer.

  9. wilma western

    logged in via email

    Another use of glyphosate in our neck of the paddocks was to kill off pasture species before either direct seeding native vegetation into shelter belts or planting tube tree stock in same. Pretty terrible really.

  10. Bob Phelps

    Director at Gene Ethics

    Genetically manipulated (GM) crops are not a growth industry. In 2010 GM crops were grown on just 7.6% of global arable land. Of that limited acreage, 45% were grown in the USA alone and 98% in just 10 countries ( Cropping systems in 165 countries and 60 dependent territories remain completely GM-free.

    The promised crops with drought and salt tolerance, nitrogen fixation in grains, longer shelf life, and more nutritional value do not exist and GM is very unlikely to deliver them…

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    1. Bernie Masters

      environmental consultant at FIA Technology Pty Ltd, B K Masters and Associates

      In reply to Bob Phelps

      The world is not short of oil - only of cheap, easily extractable oil. We're not short of phosphates for fertiliser - known deposits will meet our global needs for the next 200 years at least, but they're in politically unstable countries. We have no shortage of water, only freshwater - fortunately seawater desalination is now a proven technology with ever lowering costs of production. And we're not running short of land - we've got more than the world started with 100 years ago thanks to many (often…

      Read more
    2. Ross Barnard

      Professor; Biotechnology Program Director at University of Queensland

      In reply to Bob Phelps

      Bob- so this means we should give up trying to use GM to achieve the objectives you listed? Will they be achieved faster with conventional approaches ? Conventional approaches can work faster and cheaper for some traits (but not all). See the excellent work of Howarth Bouis for a cogent, detailed and non-emotive discussion of the later points. Many of our greatest human innovations were considered very unlikely to succeed when they were conceived. Some of the things you list will happen, just…

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  11. Bob Phelps

    Director at Gene Ethics

    Ross: just 8 GM food crops are listed in Food Standard 1.5.2. There are 48 approved GM events (genetic transformations) of those eight crops – corn 18 events; cotton 12 events; soy 7; potato 3; canola 3; sugarbeet 2; rice 1; and lucerne 1. Most are herbicide tolerance or Bt insect toxins. Though approved, many are not commercially grown anywhere as the companies are registering their events as a hedge against more huge Starlink corn or GM rice recalls that cost the industry $2 billion. Just two of…

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  12. wilma western

    logged in via email

    The Genethics spokesman Bob Phelps implies that $41 billion allegedly spent on GM crop research has been an almost total waste , mentioning CSIRO and other publicly-funded research. This seems disingenuous - how much of the alleged $41 billion was spent by Monsanto, Bayer et al? I doubt if $41 billion is the amount spent by publicly-funded institutes. I doubt if the aforementioned corporations would go on spending huge amounts on GM crop research if there was minimal scientific success and dollar return. That is unless you believe the story that the whole GM thing is a giant conspiracy by Monsanto et al to dominate global agriculture by tricking farmers into buying their seed. Funny how the anti- GM campaigners raise the Monsanto bogey when it suits , but attack the CSIRO and other institutes also when it suits.

  13. Bob Phelps

    Director at Gene Ethics

    OK Wilma - the $45 billion (not 41) didn't include public R&D budgets spent on genetic manipulation. North Dakota State University economist Dr William Wilson said: “From 1990 to 2009, major companies have collectively spent some US$45 billion on crop protection R&D, with each allocating significant sums to GM ‘seeds and traits’.” Stock Journal, 17 February 2011, p. 12.

    GM-free advocates mention Monsanto because it is the world's biggest commercial seed company and owns around 90% of all GM crop…

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  14. Anna Alvsdotter

    logged in via Facebook

    Wilma, do watch the films Food, Inc., Food Matters and The Economics of Happiness. They will help you understand the growing concern about our health and food safety here in Australia.
    The "whole GM thing" is not so much a "giant conspiracy by Monsanto", but you'd have to be very naive not to get that this is about money - lots of it. And it ain't goin' to the hard working farmers.