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Genetically modified organisms (GMOs) are living organisms whose genetic material has been artificially manipulated in a laboratory through genetic engineering. Combining genes from different organisms is known as recombinant DNA technology and the resulting organism is said to be ‘Genetically modified (GM)’, ‘Genetically engineered’ or ‘Transgenic’. This creates combinations of plant, animal, bacteria, and virus genes that do not occur in nature or through traditional crossbreeding methods. Most GM crops have been engineered to withstand the direct application of herbicide (glyphosate) and/or to produce an insecticide. However, new technologies are now being used to artificially develop other traits in plants, such as a resistance to browning in apples, and to create new organisms using synthetic biology. Despite biotech industry promises, there is no evidence that any of the GM crops currently on the market offer increased yield, drought tolerance, enhanced nutrition, or any other consumer benefit. In the absence of credible independent long-term feeding studies, the safety of GM crops is unknown. Increasingly, citizens are taking matters into their own hands and choosing to opt out of the GMO experiment.
The primary concerns of GM crops are the following:
Negative health effects because of eating genetically modified organisms
Not enough safety testing on GMOs
Allergic reactions to the new proteins that are produced
Transfer of genetic modification to wild relative
Increased pollution due to increased herbicide use
Decrease in genetic diversity of crops and animals
As the prevalence of genetically modified organisms continues to rise, there has been increasing public interest for information concerning the safety of these products. Concerns generally focus on how the GM crops may affect the environment or how it may affect the consumer. One specific concern is the possibility for GM crops to negatively affect human health. This could result from differences in the nutritional content of crops, allergic response from unnatural proteins, or undesired side effects such as toxicity, organ damage, or gene transfer. Practically all recent reviews that have critically assessed the results of GM crop/food safety research data, published in peer-reviewed science journals, have come to the conclusion that, at best, their safety has not yet been adequately established. At worst, that the results of risk assessment studies, particularly (but not exclusively) those carried out independent of the biotechnology industry, have raised important safety concerns which have not been properly settled.
The commonly raised concerns about possible implications of GM foods for human health are: inherent toxicity of the novel gene and their products, the potential to express novel antigenic proteins or alter levels of existing protein allergens, the potential for unintended effects resulting from alterations of host metabolic pathways, or over expression of inherently toxic or pharmacologically active substances, and the potential for nutrient composition in the new food differing significantly from a conventional counterpart.
Soil and Environmental Contamination
The worldwide commercial cultivation of genetically modified (GM) crops has raised concerns about potential adverse effects on the environment resulting from the use of these crops. One particular example is the Bt Corn (Bacillus Thuringensis Corn), which is widely known for its pest controlling ability. Bacillus thuringensis is a soil bacterium that has a gene that produces certain protein toxins that effectively destroy pests and insects, like larval caterpillars. This gene is then inserted into the corn to make it more resistant to pests. While this characteristic is helpful in controlling pests, this may result in the release of the said toxin to the soil. Herbicides, including glyphosate, increase plant diseases by altering plants’ ability to absorb nutrients and reduce soil health by killing microbes. Too much toxins in the soil can prevent the growth of good bacteria essential for plant growth. As a result, the soil becomes void of all necessary nutrients.
Large scale commercial planting of genetically modified crops began in 1996. Alongside concerns regarding the long-term health, environmental and socio-economic impacts of these crops, a specific concern has been that of contamination of non-GM crops by GM crops and of relatives established outside planted areas. According to the International Journal of Food Contamination, almost 400 cases of GMO contamination occurred between 1997 and 2013 in 63 countries. Part of the problem is the very nature of nature. Many plants are pollinated by insects, birds, or wind, allowing pollen from a GMO plant to move to neighboring fields or into the wild. This “genetic drift” illustrates the enormous difficulty in containing GMO technology. Not only is genetic drift impossible to prevent, inadequate regulation also fails to hold seed companies accountable for any resulting damages and ultimately puts the onus on farmers who have been the victims of contamination. Concerns regarding GM contamination of non-GM crops include loss of markets, particularly those requiring “GM-free” products; future supply of non-GM seed (especially for seed saved from open pollinated crops) and possible introgression (spreading) of the GM trait into both wild and feral populations of crop relatives.
Superweeds and Superpests
GM agriculture has led to superweeds and superpests that are extraordinarily difficult for farmers to manage. The emergence and spread of glyphosate-resistant weeds is the second, and by far the most important factor driving up herbicide use on land planted wtih herbicide-resistant varieties. Of concern is the overuse of glyphosate, a broad-spectrum herbicide commercially found in Roundup, used with seeds engineered to withstand its application. Glyphosate resistant weeds were practically unknown before the introduction of roundup ready crops in 1996. Between 1996 and 2011, U.S. herbicide use grew by 527 million pounds, mostly from glyphosate. There are now at least 14 species of glyphosate-resistant weeds throughout the country, and almost double that number worldwide. This very scenario was forewarned in a 2010 report from the National Academy of Sciences, which cautioned that the overuse of glyphosate would render it useless. Additionally, Farmers affected by resistant pests must revert to older and more toxic chemicals, more labor or more intensive tillage, which overshadow the promised benefits of GM technology.
The production of GM crops also imposes high risks to the disruption of biodiversity. This is because the “better” traits produced from engineering genes can result in the favoring of one organism. Furthermore, the introduction of genetically modified organisms can eventually disrupt the natural process of gene flow. Not only is biodiversity at risk, but beneficial insect populations are being destroyed and watersheds are being polluted.
Perhaps the best-known event illustrating the importance of genetic diversity in agriculture is the Irish potato famine. In the 1800s, much of the Irish population depended on the “lumper” potato almost exclusively for their diet. The country was a veritable monoculture – a great vulnerability that revealed itself when blight spread rapidly through the countryside, devastating the crop, the Irish population, and its economy.
Lessons from the ‘great Irish potato famine’ should be regarded. The prevalence of GMOs in major field crops threatens the genetic diversity of our food supply. Genetic diversity helps individual species adjust to new conditions, diseases, and pests, and can aid ecosystems in adapting to a changing environment or severe conditions like drought or floods. Climate change presents these exact challenges and farmers need as many tools as possible to address them – right down to the genetic code.
For thousands of years, farmers have saved seeds from one farming season to another. But when Monsanto developed genetically modified (GM) seeds that would resist its own herbicide, the glyphosate-based Roundup, it patented the seeds. The United States Patent and Trademark Office, for practically all its history, refused to grant patents on seeds, viewing them as life forms with too many variables to be patented. However, in 1980, the U.S. Supreme Court allowed for seed patents in a 5-4 decision. This laid the groundwork for plenty of corporations to start gaining control of global food supply. Over the past 15 years or so, a collection of five giant biotech corporations - Monsanto, Syngenta, Bayer, Dow, and DuPont - have bought up more than 200 other companies, allowing them to dominate access to seeds. Monsanto has become the world leader in genetic engineering of seeds, winning over 674 biotechnology patents, which is more than any other company. If you are a farmer who buys its Roundup Ready seeds, you are required to sign an agreement promising not to save the seed produced after each harvest for re-planting. You are also prohibited from selling the seed to other farmers. In short, you must buy new seeds every year.
Because saving seeds is considered patent infringement, anyone who does save GM seeds must pay a license fee to re-sow them. This results in higher prices and reduced product options, as well as the increased need for pesticides and herbicides required by GM crops. The first harvest of GM or hybrid seed varieties, with optimal irrigation, fertilizer and pesticides, yields may increase by 15 to 30 percent. However, the second generation of these seeds does not yield the same thing, instead it develops into a multitude of plant forms. Therefore, re-planting hybrid seeds is not possible, and farmers are forced to repurchase seeds every season. For the seed distributors this is truly genius, their business is protected and engineered into the very product they sell.
The following articles describe a few of the environmental topics and health concerns surrounding GMCell Biology of GM Crops
Schubert, David. "A different perspective on GM food." Nature biotechnology 20, no. 10 (2002): 969-969.
Immunological and Gastrointestinal Changes from GMO Diet
The digestive tract is the first site of contact for any ingested compound. It follows that if a compound is toxic, the first signs of toxicity may be visible in the gastrointestinal tract. Furthermore, since the stomach and intestines are the sites of longest residence for any ingested product, and the liver is a primary organ of detoxification, these should become the most important sites for the evaluation of an ingested compound's toxicity.
Carman, Judy A., Howard R. Vlieger, Larry J. Ver Steeg, Verlyn E. Sneller, Garth W. Robinson, Catherine A. Clinch-Jones, Julie I. Haynes, and John W. Edwards. "A long-term toxicology study on pigs fed a combined genetically modified (GM) soy and GM maize diet." J Org Syst 8, no. 1 (2013): 38-54.
This study concluded, "pigs fed a GMO diet exhibited heavier uteri and a higher rate of severe stomach inflammation than pigs fed a comparable non-GMO diet. Given the widespread use of GMO feed for livestock as well as humans this is a cause for concern”
DE LA, R. I. V. A. "Bacillus thuringiensis Cry1Ac protoxin is a potent systemic and mucosal adjuvant." Scandinavian Journal of Immunology 49, no. 6 (1999): 578-584.
Ewen, Stanley WB, and Arpad Pusztai. "Effect of diets containing genetically modified potatoes expressing Galanthus nivalis lectin on rat small intestine." The Lancet 354, no. 9187 (1999): 1353-1354.
Fares, Nagui H., and Adel K. El‐Sayed. "Fine structural changes in the ileum of mice fed on δ‐endotoxin‐treated potatoes and transgenic potatoes." Natural toxins 6, no. 6 (1998): 219-233.
“In conclusion, the present investigation revealed mild changes in the microscopic structure of the different cellular compartments of the ileum in a group of mice fed transgenic potatoes as compared with another group of mice fed on the -endotoxin-treated potatoes, despite the presence of the same type of toxin of Bacillus thuringiensis var. kurstaki in the transgenic potatoes as a result of gene expression.”
Malatesta, Manuela, Marco Biggiogera, Elizabetta Manuali, and MARCO BRUNO LUIGI Rocchi. "Fine structural analyses of pancreatic acinar cell nuclei from mice fed on genetically modified soybean." European Journal of Histochemistry (2003): 385-388.
Malatesta, Manuela, Chiara Caporaloni, Stefano Gavaudan, Marco BL Rocchi, Sonja Serafini, Cinzia Tiberi, and Giancarlo Gazzanelli. "Ultrastructural morphometrical and immunocytochemical analyses of hepatocyte nuclei from mice fed on genetically modified soybean." Cell structure and function 27, no. 4 (2002): 173-180.
Malatesta, Manuela, Federica Boraldi, Giulia Annovi, Beatrice Baldelli, Serafina Battistelli, Marco Biggiogera, and Daniela Quaglino. "A long-term study on female mice fed on a genetically modified soybean: effects on liver ageing." Histochemistry and cell biology 130, no. 5 (2008): 967-977.
This study observed that hepatocytes of GM-fed mice showed mitochondrial and nuclear modifications indicative of reduced metabolic rate. This study demonstrates that GM soybean intake can influence some liver features during ageing and, although the mechanisms remain unknown, underlines the importance to investigate the long-term consequences of GM-diets and the potential synergistic effects with ageing, xenobiotics and/or stress conditions.
Pusztai, Arpad. "Genetically modified foods: Are they a risk to human/animal health." Actionbioscience. org. June (2001).
Vazquez-Padron, Roberto I., L. Moreno-Fierros, L. Neri-Bazan, A. F. Martinez-Gil, G. A. De-la-Riva, and R. Lopez-Revilla. "Characterization of the mucosal and systemic immune response induced by Cry1Ac protein from Bacillus thuringiensis HD 73 in mice." Brazilian Journal of Medical and Biological Research 33, no. 2 (2000): 147-155.
Vázquez-Padrón, Roberto I., Joel Gonzáles-Cabrera, Carlos García-Tovar, Leticia Neri-Bazan, Rubén Lopéz-Revilla, Manuel Hernández, Leticia Moreno-Fierro, and A. Gustavo. "Cry1Ac protoxin from Bacillus thuringiensis sp. kurstaki HD73 binds to surface proteins in the mouse small intestine." Biochemical and biophysical research communications 271, no. 1 (2000): 54-58.
Vecchio, Lorella, Barbara Cisterna, Manuela Malatesta, T. E. Martin, and M. Biggiogera. "Ultrastructural analysis of testes from mice fed on genetically modified soybean." European Journal of Histochemistry (2004): 449-454.
Zdziarski, I. M., J. W. Edwards, J. A. Carman, and J. I. Haynes. "GM crops and the rat digestive tract: A critical review." Environment international 73 (2014): 423-433.
Ecological Risks of GM Crops
Another environmental risk associated with GM crops includes their potential impact on non-target soil microorganisms playing a fundamental role in crop residue degradation and in biogeochemical cycles.
Giovannetti, Manuela, Cristiana Sbrana, and Alessandra Turrini. "The impact of genetically modified crops on soil microbial communities." In Biology Forum/Rivista di Biologia, vol. 98, no. 3. 2005.
Losey, John E., Linda S. Rayor, and Maureen E. Carter. "Transgenic pollen harms monarch larvae." Nature 399, no. 6733 (1999): 214-214.
Rosi-Marshall, Emma J., Jennifer L. Tank, Todd V. Royer, Matt R. Whiles, Michelle Evans-White, Cynthia Chambers, Natalie A. Griffiths, J. Pokelsek, and M. L. Stephen. "Toxins in transgenic crop byproducts may affect headwater stream ecosystems." Proceedings of the National Academy of Sciences 104, no. 41 (2007): 16204-16208.
Giovannetti, Manuela. "The ecological risks of transgenic plants." In RIVISTA DI BIOLOGIA BIOLOGY FORUM, vol. 96, no. 2, pp. 207-224. ANICIA SRL, 2003.
Tank, Jennifer L., Emma J. Rosi-Marshall, Todd V. Royer, Matt R. Whiles, Natalie A. Griffiths, Therese C. Frauendorf, and David J. Treering. "Occurrence of maize detritus and a transgenic insecticidal protein (Cry1Ab) within the stream network of an agricultural landscape." Proceedings of the National Academy of Sciences 107, no. 41 (2010): 17645-17650.
Wolfenbarger, Laressa L., and Paul R. Phifer. "The ecological risks and benefits of genetically engineered plants." Science 290, no. 5499 (2000): 2088-2093.
GM Crops Increasing Insecticide Usage and Resistant Weeds
Benbrook, Charles M. "Impacts of genetically engineered crops on pesticide use in the US--the first sixteen years." Environmental Sciences Europe 24, no. 1 (2012): 24.
Conclusions: Contrary to often-repeated claims that today’s genetically-engineered crops have, and are reducing pesticide use, the spread of glyphosate-resistant weeds in herbicide-resistant weed management systems has brought about substantial increases in the number and volume of herbicides applied. If new genetically engineered forms of corn and soybeans tolerant of 2,4-D are approved, the volume of 2,4-D sprayed could drive herbicide usage upward by another approximate 50%. The magnitude of increases in herbicide use on herbicide-resistant hectares has dwarfed the reduction in insecticide use on Bt crops over the past 16 years and will continue to do so for the foreseeable future.
Heap, Ian M. "The occurrence of herbicide‐resistant weeds worldwide." Pesticide science 51, no. 3 (1997): 235-243.
Alteration and Reduction of Phytonutrients in GM Crops
Bøhn, Thomas, Marek Cuhra, Terje Traavik, Monica Sanden, J. Fagan, and R. Primicerio. "Compositional differences in soybeans on the market: glyphosate accumulates in Roundup Ready GM soybeans." Food chemistry 153 (2014): 207-215.
Abstract: This article describes the nutrient and elemental composition, including residues of herbicides and pesticides, of 31 soybean batches from Iowa, USA. The soy samples were grouped into three different categories: (i) genetically modified, glyphosate-tolerant soy (GM-soy); (ii) unmodified soy cultivated using a conventional “chemical” cultivation regime; and (iii) unmodified soy cultivated using an organic cultivation regime. Organic soybeans showed the healthiest nutritional profile with more sugars, such as glucose, fructose, sucrose and maltose, significantly more total protein, zinc and less fiber than both conventional and GM-soy. Organic soybeans also contained less total saturated fat and total omega-6 fatty acids than both conventional and GM-soy. GM-soy contained high residues of glyphosate and AMPA (mean 3.3 and 5.7 mg/kg, respectively). Conventional and organic soybean batches contained none of these agrochemicals. Using 35 different nutritional and elemental variables to characterize each soy sample, we were able to discriminate GM, conventional and organic soybeans without exception, demonstrating “substantial non-equivalence” in compositional characteristics for ‘ready-to-market’ soybeans.
Lappe, M.A., Bailey, E.B., Childress, C. and Setchell, K.D.R. (1999) "Alterations in clinically important phytoestrogens in genetically modified, herbicide-tolerant soybeans." Journal of Medical Food 1, 241-245.
Abstract: “The growing clinical interest in and use of soybean-based food products or extracts to increase dietary phytoestrogen intake makes the precise composition of the key biologically active ingredients of soybeans, notably genistin and daidzin, of substantial medical interest. Conventional soybeans are increasingly being replaced by genetically modified varieties. We analyzed the phytoestrogen concentrations in two varieties of genetically modified, herbicide-tolerant soybeans and their isogenic conventional counterparts grown under similar conditions. An overall reduction in phytoestrogen levels of 12-14% was observed in the genetically altered soybean strains, mostly attributable to reductions in the concentrations of genistin and, to a lesser extent, in daidzin. Significant sample-to-sample variability in these two phytoestrogens, but not in glycitin, was evident in the genetically altered soybeans. Given the high biological potency of isoflavones and their metabolic conversion products, these data suggest that genetically modified soybeans may be less potent sources of clinically relevant phytoestrogens than their conventional precursors. These observations, if confirmed in other soybean varieties, heighten the importance of establishing baselines of expected isoflavone levels in transgenic and conventional soy products to ensure uniformity of clinical results. Disclosure of the origins and isoflavone composition of soyfood products would be a valuable adjunct to clinical decision-making.”