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 crops (P. Windels, et al. European Food Research Technology, 2001). Examples include: Roundup Ready soya (A. Rang, et al. European Food Research Technology, 2004) and insect resistant maize, MON810 (M. Hernandez, et al. Transgenic Research, 2003).
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.
No Solution for Hunger
The United Nations/World Bank assessment of agriculture (IAASTD, “Agriculture at a Crossroads,” 2009) 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 US” (IAASTD, “Agriculture at a Crossroads,” 2009).
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” (IAASTD, “Agriculture at a Crossroads, 2009).
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 [residents of Victoria, Australia] experienced food insecurity.
Solutions to hunger and malnutrition are not easy. But supporting farmers and farm workers in eco-agriculture systems that minimize dependency on external inputs, such as artificial fertilizers and pesticides, is a major option to fight hunger and improve food security worldwide (C. Nellemann, et al. “The Environmental Food Crisis,” 2009).
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 literature (J. Cotter, Greenpeace Research Laboratories, 2009) and are summarized 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 larvae (Galen P. Dively, et. al., Entomological Society of America, 2004).
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 target (S. Wang, et. al, International Journal of Biotechnology, 2008). 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 focused 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 review (P. Riley, et. al., Herbicide Tolerance in GM Crops, 2011) but are summarized briefly here.
There are concerns Roundup (or glyphosate) is toxic to aquatic biodiversity (Rick A. Relyea, Ecological Applications, 2005), 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 microorganisms (R. J. Kremer and N. E. Means, European Journal of Agronomy, 2009).
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.
Food Safety
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 approved (ANAO, Food Standards Australia New Zealand, 2010), despite these gaps.
In 2005, the development of an Australian GM pea was dramatically stopped because a study found serious health impacts in mice (Vanessa E. Prescott, et al. Journal of Agricultural and Food Chemistry, 2005). 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 said (Editorial, New Scientist, 2005):
“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.
Dr. Janet Cotter is a senior scientist at the Greenpeace International Science Unit, based at the University of Exeter UK, supporting Greenpeace’s campaigns on forests and agriculture. This article was first published on The Conversation (theconversation.edu.au ) and is a reply to the article ‘Top Five Myths About Genetic Modification.’
