GM Crops – Friend or Foe?

Last July billionaire Bill Gates was criticized for donating around US$10 million to the John Innes Centre in the United Kingdom to fund their research which helps the developing world. Why? Because they work on developing genetically-modified (GM) crops. GM crops receive a lot of publicity. They are cast positively as a potential savior of famine-struck countries, with the potential to be more nutritious, higher-yielding, and resistant to pests and extreme weather conditions. Were this true, then surely there would be very little opposition. So why is there so much controversy? Well, because it has become apparent that achieving these goals comes with a lot of difficulty, and because of the threat of potentially disastrous side-effects.

To start, it helps to clarify an under-explained fact: GM crops are ‘unnatural’ in a precise scientific sense. The fundamental difference is that nature allows genes to swap between plants of the same species, such as two tomato plants. But nature will never see genes mixing between two completely different plants (or indeed between a plant and an animal – remember the ‘Fish Tomato‘ (Hightower 1991)?), which is often what happens to produce GM crops. Swapping genes within a species occurs in an organized, well-regulated fashion. However, swapping genes between two completely different species is, frankly, a bit of a genetic mess and can lead to undesirable and unpredictable side-effects.

The fact that the GM process is ‘unnatural’ does not make it bad in itself. After all, organs are not transplanted by natural processes and without vaccinations diseases like polio would still be ravaging the world. Undoubtedly, modern medicine is a great thing no matter how unnatural it may be. There are few objections because we know that it works and that any side-effects are minor relative to the benefits gained. In addition, drugs must go through several years of thorough scientific testing before they are approved whereas GM crops do not necessarily even have to be tested on humans. In the case that a drug turns out to have negative side-effects, at least the effects are contained i.e. the effects of drugs do not spread uncontrollably from one organism to another. But this is one of the big risks of GM crops – the engineered gene may spread to other crops through cross-pollination or by lingering in the digestive tracts of wildlife with unknown effects. Testing GM crops thoroughly would entail trialling the effects of their interaction with every other organism with which they could possibly come into contact. Clearly, this is impossible without actually unleashing the crop into said ecosystem, and once this is done the process is irreversible.

Despite the risks, do GM crops at least achieve their aims? One of the most high-profile cases is Vitamin A-rich ‘Golden Rice‘, designed to be grown in developing countries where Vitamin A deficiency kills around 670,000 children every year (Black 2008). The deficiency also adds to many countries’ already high maternal mortality figures by causing the often deadly night blindness, a condition that makes it practically impossible to see in relatively low light and that can reduce the body’s capacity to fight off infectious disease like measles. After more than a decade, Golden Rice is still unavailable on the market due to fundamental problems with its development. For example, the first variety lacked sufficient Vitamin A levels meaning that it had to be consumed in huge quantities to have any benefit and therefore a new variety had to be created. Other varieties do not grow well on the Asian farms at which they are targeted and therefore are being cross-bred with natural varieties that do grow well in these places. Similar development problems have occurred with other GM crops such as virus-resistant cassava and high-protein cassava.

As for the risks, well playing with genes is a very complicated business because a single gene does not act alone in isolation. It interacts with other genes in ways which are far too complex for us to predict, let alone control. We may select a single gene which renders a plant resistant to disease, but that gene in combination with other genes can produce other unpredicted effects. Some may be unimportant, but on occasions it can result in crops that are toxic to wildlife. Examples include laboratory tests on animals which show that rats fed GM tomatoes developed stomach ulcers, and others found that mammals fed with GM soy and maize showed signs of toxic effects in the liver and kidneys. In contrast, natural selective breeding has produced, and continues to produce, crops with many of the beneficial traits that GM attempts to produce, such as drought-resistance. These days the selection process is made much more efficient by techniques such as ‘marker-assisted selection’ (MAS) where an easily identifiable ‘marker’ (such as a specific sequence of DNA) is inserted to make it easier to track the target gene. Techniques such as these are sometimes confused with GM techniques, leading to GM technology being given credit for their success. In particular, crops produced by GM or by MAS techniques are both termed ‘biotech crops’, misleading the public into thinking that the two techniques are the same. Drought-tolerant maize was developed using non-GM techniques, then herbicide tolerance was added via GM methods. The result is that all the positive attributes of the crop are assumed to arise from genetic modification.

Cynically, it might be said that research continues because of the financial interests of the private GM crop companies that stand to make huge profits from the business – once a GM crop is designed, the crop is patented and owned by the company that made it. ‘Biopiracy’ is the term used when a company takes an indigenous crop, often developed over several generations by indigenous populations, modifies it, and then claims it as their own. Recently, India (closely followed by Brazil) launched legal action against Monsanto, one of the world’s largest biotech companies, for doing precisely this. In other cases, it is hard to believe that GM companies are really working to help the developing world when the crops they sell turn out to be more expensive to grow than conventional varieties: an example is GM cotton sold to Indian farmers which was designed to be resistant to bollworms but turned out to be susceptible to aphid attack, forcing the farmers to buy expensive chemical pesticides.

Many studies of GM crops, which claim that they are successful, are commissioned by the very same companies who produce them. This puts the credibility of the studies in doubt. If GM companies want to convince the world of their benefits, they need to allow independent scientists to perform independent studies and make the results public. An example of such a study is the GMO Myths and Truths report. The authors separate the scientific evidence from the rumors to explain how GM and non-GM crops balance against each other. As a scientist, I then automatically ask why this report should be any more reliable than those commissioned by GM companies? There is no obvious reason why the authors should have any personal bias, but this does not mean that they don’t. How do we know that the studies which report negative findings of GM crops are not also biased, selectively choosing evidence to sway their readers? Short of looking carefully through all the references cited and ascertaining how scientifically sound each one is… we don’t. Since GM technology is such a controversial topic with very high stakes, and scientifically quantifying the risks is virtually impossible, performing or finding a truly objective and scientifically reliable study is difficult.

In view of this, my conclusion is that even if you could claim that the risk of GM crops having a negative effect on the environment is low, the fact is that the effects, although unlikely, could be disastrous and irreversible if they did happen and could end up doing severe harm to the very people we are trying to help. So we have to weigh up a low-probability event with very bad consequences against the benefit gained. If it were necessary to engineer GM crops due to an inability to produce food by other methods, one would have to balance the risk against the starvation of several million people. However, it is well known that there is sufficient food in the world to feed everyone: people are starving due to political instability and corruption, and the inability to access food due to lack of money or transportation. It is not due to a lack of food. So it must be the case that non-GM methods can provide sufficient food, and that this comes with no risk because they follow natural methods which nature has happily used for millions of years. Therefore using GM crops means taking a (perhaps small) risk for… well, for what exactly? Definitely there is a need to develop crops which are more resilient to the harsh weather conditions of the global South so that these countries can be self-sufficient, but natural methods are making headway here too. So why continue to take the risk with GM technology? Perhaps the answer is profit.

      Potential pros       Cons
  • Crops resistant to pests and weeds – eliminates the need for chemical pesticides.
  • Crops resistant to extreme weather conditions.
  • Crops more nutritious.
  • Crops produce higher yields.
  • More efficient than conventional breeding (in terms of space and time needed).
  • All possible benefits have yet to be proven.
  • Risk of genes from a GM crop transferring to other organisms and affecting the entire ecosystem.
  • Pest-resistant crops actually increase the rate at which pests become immune to the pesticide, so stronger chemical pesticides are required.
  • GM crops lack rigorous testing and risks are unquantified.

Can you think of any other pros and cons of genetically-modified crops? Please leave a reply below.

Tracey Li is a Research and Communications Intern with INESAD.

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For your reference:

Antoniou, M, Robinson, C, Fagan, J 2012, GMO Myths and Truths. <

Black RE et al., ‘Maternal and child undernutrition: global and regional exposures and health consequences’, The Lancet, 2008, 371 (9608), p. 253. <>

Benson, J 28th September 2011, GlobalResearch, India files biopiracy lawsuit against Monsanto, says biotech giant is stealing nature for corporate gain. <>

Enserink, E 2008, ‘Tough Lessons From Golden Rice’, Science 25 Vol. 320 no. 5875 pp. 469-471.  <>

Haerlin, B 2001, Greenpeace, GE rice is fool’s gold.<>

Hightower, R, Baden, C, Penzes, E, Lund, P, Dunsmuir P 1991, ‘Expression of antifreeze proteins in transgenic plants’, Plant Mol. Biol. 17, pp. 1013-21.

Hines, FA 1993, Department of Health & Human Services Memorandum. <>

Lakhani, N 16th July 2012, The Independent, Anger after Bill Gates gives £6m to British lab to develop GM crops. <>

Nemana, V 7th December 2012, The New York Times, In India, GM Crops Come at a High Price. <>

Paine, AJ et al. 2005, ‘Improving the nutritional value of Golden Rice through increased pro-vitamin A content’, Nature Biotechnology 23, pp. 482-487. <>

Portillo, Z 2012, SciDev, GM cassava study retracted over ‘missing’ data.                                                  <>

Séralini, GE, Mesnage, R, Clair, E, Gress, S, de Vendômois JS, Cellier, D 2011, Genetically modified crops safety assessments: Present limits and possible improvements, Environmental Sciences Europe 23 (10).

Tencer, D 2011, The Huffington Post Canada, Monsanto, World’s Largest Genetically Modified Food Producer To Be Charged With Biopiracy In India (VIDEO). <>

Varma, S 12th June 2012, The Times of India, Five million Brazilian farmers take on biotech giant Monsanto. <>

Ye X, Al-Babili S, Kloti A et al., Engineering the provitamin A (beta-carotene) biosynthetic pathway into (carotenoid-free) rice endosperm, Science. Jan 14 2000, 287(5451) pp. 303-305. <>

The Center for Food Safety, International Forum on Globalization, ‘Scientists and Government Regulators Speak Out Against Genetic Engineering’. <>

2004 ‘Monsanto’s showcase project in Africa fails’, New Scientist, Vol 181 No. 2433, 7. <>

2012 GMWATCH. <>



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  1. I think GM crops should be examined by scientist before making an assumption that it is safe for food consumption since there are adverse effects of GM crops which may result to serious human diseases such as cancer, typhoid and many others.

  2. I have seen GM cotton plantation, known as BT cotton as well, if I get it right. This GM cotton requires 3 times more water intake than ordinary local cotton. The residue of ordinary cotton is used for making rape-seed / lin-seed cakes for oil and animal fodder. BT cotton residue has no oil, hence no lin-seed cake / lin-seed oil, and also animals cannot chew the fodder made from dry stems of BT cotton. More pesticied has to be used for GM cotton compared with traditional.

    Land on which GM cotton has been planted, has to be kept fallow for a longer period after harvest. Weeds growing on the fallow land have little or no compost / natural fertilizer value.

    However, the GM cotton fibers are longer compared with traditional. The plant is shorter, and yields more crop.

    The local farmers in our are have experimented and factored that planting GM cotton is more expensive and hazardous in the long run.

    • Hi Faruque. Thanks for your comments – it’s nice to hear from someone who has first-hand experience of the topic.


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