What are Genetically Modified Organisms?
Selective breeding is a well established practice in both plants and animals, practiced for thousands of years. The most desired genetic traits are sought out by crossing one species with another. This creates a superior specimen, aiming to remove deleterious traits.
Desired outcomes in organisms include:
- Higher yields
- More resilience to climatic conditions
- Greater nutritional value
- Increased resistance to disease
- Less use of pesticides.
Definition of Genetic Modification:
“Altering the genetic trait of a living organism by using recombinant DNA technology to transfer one or more genes from one organism to another, bypassing biological species”.
Genetic engineering seeks to take breeding a step further. By being highly selective of the genes that cross; GE produces a specimen which result in the desired outcomes.
Breeding is a time consuming process and will not always bring about desired outcomes. This opens the door for a more expedited process. However, the extent to which the current processes can be safely replicated artificially is questionable.
Why Are They Necessary?
Genetically modified organisms are a way to address the growing global population and climate change. With a growing population there is a greater pressure to feed more people. Without the loss of crops to pests and harsh environmental conditions yields increase. Genetically modified crops are also used to reduce the use of pesticides. Some pesticides have a negative impact on the environment and human health (16).
The use of GM has the potential to alter the nutritional content of foods. Nutritionists expect a higher nutrient content, and better availability of nutrients. They also expect less anti nutritional factors from the use of biotechnology (1).
GM’s as nutraceuticals – engineering foods preventing allergies or intolerances to certain foods. GM’s used to increase the nutritional value of a food. Increasing the lycopene content in tomatoes for prevention/treatment of heart disease (12).
Recombinant DNA technology is also used to produce provitamin A in rice. This is usually lost from the endosperm during processing and storage after harvest. This intervention has the potential to address Vitamin A deficiency across many countries (3).
Fig 1. Novel Food Crops Under Development
Harry A. Kuiper, Gijs A. Kleter, Hub P. J. M. Noteborn, Esther J. Kok. 2001. Assessment of the food safety issues related to genetically modified foods. The Plant Journal Volume 27, Issue 6 September 2001 Pages 503–528.
There are good motives for the use of Genetically modified crops. Yet, there isn’t anything that GM crops can do that natural procedures cant. Through sustainable agricultural systems.
Organic agriculture is an established way of improving yields, providing environmental and social benefits (14,15,16). Significant increases in yields result from teaching farmers sustainable practices:
- Better soil nutrition
- Improved pest and disease control
- Water use efficiency
- Better weed control methods and Ecological intensification (13).
Fig 2. Push, Pull Agricultural Method. Using Plants As Natural Pesticides.
If there are already ways to increase yield, reduce pests and weeds then why GMO? What are the motives? Is it profit incentives? Genetically modified foods can be patented meaning seeds sell year after year. This mimics the highly profitable pharmaceutical model.
It isn’t so much that a lack of yields or loss of crops due to environmental conditions causes world hunger but:
“Inefficient, unfair distribution systems, agricultural commodity speculation, poor farming methods and political crises that causes world hunger” (13).
It isn’t a question of food production but access to food. The hungry cannot afford to pay for it. So are GMOs really a viable solution to world hunger when the problem isn’t the production but the food system itself?
Genetic modification has potential. That is if it does have the ability to consistently produce favourable genetic outcomes, without unintended effects. All whilst under safe regulatory scrutiny of course. When fully understood they could have a place alongside sustainable practices. We could produce quality foods low in pesticide residues and high in nutritional value.
The real concern with GMO’s is the effect that they will have on the consumer. Will long term consumption of these foods result in disease, or could they provide optimal nourishment?
Current understanding establishes a few inconsistencies in the expected outcomes of genetic engineering:
“Introduction of the same gene into two different types of cells can produce two very distinct protein molecules. Second, the introduction of any gene,whether from a different or the same species, usually significantly changes overall gene expression. This changes the phenotype of the recipient cell. Third, enzymatic pathways introduced to synthesize small molecules, such as vitamins, could interact with endogenous pathways to produce novel molecules”(9).
The Consequences Of Inconsistency
Indian agricultural labourers reported reactions of the skin, eyes and upper respiratory tract after handling Bt Cotton. Some required hospitalisation. 23 labourers had handled non-gm varieties of cotton before and had not displayed allergic responses (10).
Bt corn pollen
100 filipinos living next to a Bt corn field developed skin, respiratory, intestinal reactions and other symptoms whilst the corn was releasing pollen. Blood tests of 39 people showed an antibody response to Bt-toxin suggesting a correlation but not causation (11).
Allergenicity may result from new proteins or by their interaction with usual proteins, producing a new allergen (1).
Concern about the potential of pleiotropic or unintended effects. For example, altered gene expression leading to increased levels of anti-nutrients, novel toxins or allergens, as a result of the insertion event” (2).
Transgene location might cause:
“the food derived from the plant to have higher levels of toxins than normal, or lowered levels of a significant nutrient (8).
“Genes in a corn or soybean plant may react on a similar scale to the insertion of a transgene. The changes may result in:
“synthesis of toxic, carcinogenic, teratogenic [causing changes in the fetus], or allergenic compounds”. And inhibit “the synthesis of a beneficial plant molecule” (9).
There are a few concerns when it comes to the safety of GMO foods. The current measures put in place to safeguard against disease and outbreak:
Toxicity from consumption of Genetically modified foods can become apparent relatively quickly. But, with diseases of longer term onset like cancer there is no way of detecting it in the short term. Without labels on GMO foods, there is no traceability to account for potential reactions. So it would be pertinent to hold back on the release of GMO products to the global market. Not until long – term studies exist on humans to establish the safety of such products to establish any adverse effects. For the current GMO’s on the market, they should have labels to allow the consumer a choice in what they wish to consume.
The evaluation methods used to assess the safety of GMO foods isn’t gold standard in the assessment of potential adverse effects that could occur.
Substantial equivalence assures that novel foods are as safe and nutritious as conventionally grown foods by assessing:
(a) the properties of the introduced trait (gene).
(b) any effect generated by the introduction or expression of the new trait in the crop or food (1).
Chemical analysis alone cannot conclude the safety of a novel plant that has been genetically modified (5). “Substantial equivalence is not, and has never been a synonym of safety, neither in Europe, nor in the United States” (1).
Substantial equivalence assesses the nutritional and anutritional components of a plant. If similar to conventional produce, GMO counterpart foods pass as safe. This is due to the complications of evaluating the potential toxicity of whole foods. This evaluation is not thorough enough to deem foods safe to consume. Not if only based on nutritional and anutritional components. These are not solid indicators of potential adverse effects from long term consumption.
Common Food Sources
Rowland IR. Genetically modified foods, science, consumers and the media. Proceeding of the Nutrition Society. 2002;61:25-9.
Throwing caution into the wind is not something of interest when considering the widespread use of GMO’s. Certainly not before testing and evaluation looking for unexpected outcomes.
Scientific evidence exists showing the inconsistencies in outcomes. We don’t know for sure if GMO’s may pose potential health risks for the general public yet. Additionally, the lack of gold standard assessment to fully measure the safety of these foods for consumption needs attention.
Impressions for GMO’s aren’t helped by the unethical business practices of some pioneering GM company(s). This has done a good job of swaying opinion about GMO. From unethical business to flawed scientific research, named corporation(s) have left a bad taste in the mouths of people around the world. Even before GMO has been fully explored responsibly.
“Biotechnology is innately neither good nor bad. It has the potential to alleviate or aggravate the impact of agriculture on the environment. The challenge for all of us is to develop, supply, and manage biotechnology for the benefit of humankind and the environment”(4).
If there is great confidence in the efficacy and safety of current GMO’s then there shouldn’t be any concern in undertaking long-term human studies to prove it. Until those studies exist to clarify the absence of complications with current methods, and understanding of genetic engineering, it is worth giving GMO’s some time.
- Bertoni G, Marsan AP. Safety Risks for Animals Fed Genetic Modified (GM) Plants. Vet Res Commun 2005;29(Suppl 2):13-8.
- Rowland IR. Geneticaly modified foods, science, consumers and the media. Proc Nutr Soc 2002;61:25-9.
- Ye XD, Al-Babili S, Kloti A, Zhang J, Lucca P, Beyer P & PotrykusI (2000) Engineering the provitamin A (beta-carotene) biosynthetic pathway into (carotenoid-free) rice endosperm. Science 287, 303–305.
- Dale, P.J., 2001. Environmental impact of biotech crops. Journal of Animal Science, 79(E. Suppl.), E144–E147
- Aumaitre, L.A., 2004. Safety assessment and feeding value for pigs, poultry and ruminant animals of pest protected(Bt) plants and herbicide tolerant (glyphosate, glufosinate) plants: Interpretation of experimental results observed worldwide on GM plants. Italian Journal of Animal Science, 3, 107–121
- US FDA Premarket notice concerning bio-engineered foods: Proposed rule, “federal register 66:4706-38.
- David Schubert, “A Different Perspective on GM Food,” Nature Biotechnology 20, no. 10 (October 2002): 969.
- Ashish Gupta et. al., “Impact of Bt Cotton on Farmers’ Health (in Barwani and Dhar District of Madhya Pradesh),Investigation Report, Oct–Dec 2005.”
- “Study Result Not Final, Proof Bt Corn Harmful to Farmers,” BusinessWorld, 02 Mar 2004.”
- Arab L, Steck S. Lycopene and cardiovascular disease. Am J Clin Nutr 2000;71:1691-5.
- Smallholder Organic Farming not GMOS – the Solution to World Hunger. OFA ORGANIC UPDATE – FEBRUARY 2011 – SPECIAL ISSUE
- Badgley et al, (2007), Organic agriculture and the global food supply, Renewable Agriculture and Food Systems (2007), 22: 86-108
- FAO (2007), FAO international conference on Organic Agriculture and Food Security, 2007: Organic agriculture can contribute to food security, Food and Agriculture Organization of the United Nations, Rome, Italy
- Pimentel D et al (2005), Environmental, Energetic and Economic Comparisons of Organic and Conventional Farming Systems, Bioscience (Vol. 55:7), July 2005
- Leu A (2004), Organic Agriculture Can Feed the World, Acres USA, Vol. 34, No1
- Hayo M.G. van der Werf . Assessing the impact of pesticides on the environment. Agriculture, Ecosystems & Environment. Volume 60, Issues 2–3, December 1996, Pages 81–96