Researcher holding up a GMO vegetable in the laboratory
© Monika Wisniewska via iStockphoto.com
Genetically Modified Organisms: Is it Nice to Fool Mother Nature?
by Thelma Lee Gross, DVM
This is Part 2 of a two-part series. You can read Part 1 here.
Some Problems with GMOs
It is not surprising that genetic modification is not without its costs. Most of these relate to potentially negative environmental impact. Nothing is free, and certainly not GMOs. This section will deal with some of the issues that have arisen and may arise as a result of genetically modified food crops.
Antibiotic Resistance Genes Amflora potatoes, one of the older GMOs, is used in industry (See Part 1). It contains an antibiotic resistance gene that is used as a marker for genetic modification. Antibiotics are applied to select the successfully modified product which co-expresses resistance to the antibiotic used. If the product is modified correctly, it survives because it also resists the antibiotic. However, this resistance gene could theoretically be transferred to bacteria by direct exposure of the modified potato to the environment in which bacteria abound.
As concerns over antibiotic resistance are increasing rapidly in the modern medical world, this technique of selection should be discontinued and, in fact, is considered antiquated by current standards of GMO production. Newer GMOs are confirmed via the use of polymerase chain reaction (PCR) testing or bioassays. Nevertheless, this potato was approved for planting in Europe in
2009.
Agricultural Test Area © Andres Reh vis iStockphoto.com
Herbicide Ready Issues In theory, if a crop is resistant to an herbicide, then that herbicide (usually glyphosate, Roundup) can be used with impunity, and weed control is achieved without tilling (See Part 1). However, recent evidence by Michael Owen, a weed scientist at Iowa State University, indicates that “weed communities” are shifting as a result of the practice of planting glyphosate-resistant crops and then focusing on the use of one herbicide. The genetic trait itself seems to be having no direct effect on the weed communities via crossbreeding; rather, it is the overall method of weed control that is creating local pressure to shift the weed communities to those that include glyphosate- resistant species, creating
new problems for the farmer. The
conclusion by Owen and Green is that diversified weed management systems, as well as new herbicides, will need to be developed. This seems to negate the benefits of herbicide resistant GMOs, and it may ultimately increase the need for a variety of potentially more toxic products.
Although scientists are indicating that these weed shifts can lower crop yields, in House oversight meetings in October 2010, Ann Wright, a deputy undersecretary of the Agriculture Department, said the department “lacked authority” to restrict herbicide-tolerant crops, much to the dismay of Rep. Dennis Kucinich (D-Ohio), who is working on the superweed issue. He stated the Department could stop herbicide-ready crops under its noxious weed law, of which Wright was apparently ignorant. According to Wright, the USDA can only regulate herbicide-tolerant crops as pests themselves but cannot stop farmers from using the crops, even if they lead to the development of resistant weeds. The Environmental Protection Agency said it had raised the weed-resistance issue with the USDA and was in “conversation” with them. At that hearing, Owen, who has also worked on a National Research Council, said he believed it is
too late anyway because farmers have come to rely on the use of one herbicide (glyphosate) alone. Currently 93% of the soybeans and 70% of the corn planted in the USA in 2010 were herbicide tolerant varieties.
In October 2010, current Roundup Ready plants (stecklings) from sugar beet rootstock were
ordered to be removed from the ground by Judge Jeffrey White in San Francisco, due to a lawsuit involving the Sierra Club, Organic Seed Alliance, and other plaintiffs. This suit followed USDA-issued permits to plant the stecklings, even though White had revoked the federal deregulation of seeds and crops containing the Roundup Ready trait in August, pending a new environmental study. However, this week the USDA decided to allow the current crop to be harvested, even though the environmental study will not be released
until 2012.
It is clear that glyphosate-resistant crop plants may function as weed pests. Herbicide-ready rapeseed (canola) often is alternated with other crops and can show up as a weed in the alternate crop’s plantings the following year. This
may force the use of more persistent and different herbicides and is certainly not the intended effect of this GMO.
These problems are significant and quite possibly outweigh the benefits. If this type of GMO ultimately creates an increase in pesticide use and begins to function as a weed itself, then it should be removed from the market and other alternatives sought.
GMO Cotton (South Africa) © Brasil2 via iStockphoto.com
Bt Issues There is some evidence that the prolonged use of Bt crops can create emergence of resistant insect strains or elevation in populations of insects that are naturally resistant; these would likely have emerged with the use of Bt alone. There is
recent field evidence that certain strains of mirid bugs have acquired pest status in areas of China where Bt cotton is grown.
In essence, any responsible program of genetic modification that involves pests like weeds and insects should be considering the emergence of resistance. Bt crops remain useful because of the significant reduction in production costs and relative safety of this type of pesticide. Characterizing the mutations that enable resistance could lead to the development of molecular tools to monitor resistance in the field, as well as new genetically modified crops that stay ahead of pest resistance without the use of toxic external products. This might be achieved by further studies like those described in Part 1, where naturally occurring pest-resistance genes are transferred from one plant to another in a “share the wealth” approach to pest control.
Genetic Drift The increasing use of GMOs often means that the variety of planted strains is diminished as farmers adopt more lucrative crops. In places where there are heritage strains of importance to native farmers and consumers, cross pollination from modified crops becomes a real worry. In Mexico, for example, concern for the genetic pollution of native varieties has spurred protests, despite evidence that using genetically modified corn ultimately may provide independence from imported U.S. corn by substantially increasing domestic yield. Native varieties in some areas already contain genes from genetically altered corn. The fear is that indigenous species that display adaptive traits for certain challenged regions may lose those advantages by exposure over time to genetically modified corn. This has not yet been found. Hybrid corn already exists in Mexico and has been
regularly mixed with native corn varieties. Genetically modified canola (rapeseed) has been growing in the wild, and has apparently crossbred with native strains, according to a
survey in August of 2010 by the Ecological Society of America.
These results indicate that genetically modified organisms, like all organisms, cannot be contained and will interbreed to a varying extent. The effect of the proposed trait on the environment should be studied prior to release and traits such as herbicide resistance should be avoided. For the sake of genetic banking alone, not to mention the cultural importance of crop and other plants, heritage varieties should be carefully protected by strict segregation from GMOs. This is also important for organic farmers who cannot market their food if “contamination” by GMOs is identified.
Bt genetic material
has been identified in tissues of wild mussels. Mussels likely receive the genes during feeding when they ingest Bt contaminated microorganisms. The long term effect of such exposure to these lower organisms of the food chain is not yet known; Bt is not known to be toxic to any organisms other than insect larvae. But it is conceivable that other effects of environmental spread of GMOs may emerge as further studies are made.
Genetic Engineering (Plant) © espion via iStockphoto.com
The Influence of Industry
GMOs are often promoted as the one-stop solution in the management of the world’s food problems and instead should involve an integrated and holistic approach. Such strong emphasis on this silver bullet of biotechnology is promulgated by industry, which has a strong vested interest in GMOs.
The Monsanto Company is the world’s largest producer of genetically engineered seed, including Roundup Ready products, and controls over 90% of the world’s genetically engineered seed production. Monsanto came under investigation by the U.S. Justice Department in 2009 as a result of its business strategies and licensing agreements. For example, Monsanto
does not permit independent companies to breed plants that contain both Monsanto's genes and the genes of any of its competitors, called “stacking,” unless Monsanto gives prior written permission.
In
some cases, this company is clearly influencing or controlling which scientific studies of GMOs are done and published. Some researchers working with GMOs have apparently had to pry the data for testing out of Monsanto via
Freedom of Information filings and lawsuits. Although their secrecy may have something to do with proprietary issues, this resembles a cover-up to the public. Monsanto does not claim responsibility for the genetic drift from its GMOs, and in the case of GM canola spreading to the wild,
disingenuously tried to make it an issue of patent rights.
The final section of this series will attempt to balance the pros and cons of GMOs from an ethical perspective, with a view to the future of our world.
Genetic Modification in Balance
The core of our distrust of genetic modification is that we do not like the idea of humans manipulating a genome of anything, not even a bacterium. It conjures up a fear of mad scientists creating monsters fused from fish and elephants or birds and snakes. One internet poster, for example, shows a fruit viciously biting its consumer and was featured on a previous post of this blogsite. There is a fear of the “slippery slope” and that ultimately we will manipulate our own genome for eugenics, and not just to avert or reverse genetic disease (See Part 1). We are already
engineering farmed salmon to grow more quickly, although the FDA has not yet given its approval. And recently scientists in Canada engineered a pig to produce phytase, an enzyme that helps in the digestion of cereal grains. This obviates addition of phosphorous to their diet. This reduces production costs and allegedly reduces phosphorous contamination of the environment. Pigs are mammals. Are we far behind?
The Case for Human Disease Human
gene therapy is a natural outcome of genetic manipulation and in essence creates GMOs of us humans, but in a “good way.” Diseases that lend themselves well to gene therapy include sickle-cell anemia, Tay-Sachs disease, Duchenne muscular dystrophy, Huntington's chorea, and cystic fibrosis, as these occur from mistakes involving single nitrogen bases of a DNA molecule. If a correct copy of a given gene can be successfully inserted and then assume its normal function, these genetic disorders may be cured. Research has begun in combined immunodeficiency disorder and alpha-1-antitrypsin deficiency of humans, among other diseases.
If we do not like the idea of genetic engineering, aren’t we willing to relax our disapproval when it means saving lives? You bet we are. Although we can all imagine an end point, the horrific one involving designer offspring and new creatures created from genetic parts of others, can we not be selective in the use of genetic modification? Can we not pull back when problems emerge and forge ahead when real benefits are gained? I think we can.
A Balanced Approach The most laudatory stated goal of genetic modification of our food is that of fighting starvation and malnutrition. But genetic modification should not be touted as the end-all and be-all of agriculture’s successful future. As we have seen, GMOs can grow in areas of environmental deprivation, such as in high saline soils and in areas of low water availability. They can increase the availability of nutrients. However, it is possible to conventionally breed many of these traits into foods, as organizations like
HarvestPlus are doing. Iron, zinc and vitamin A are the principle targets of this organization’s efforts at biofortification. HarvestPlus is producing sweet potatoes with beta carotene and is working on a similar corn crop. Cassava with beta carotene; iron-rich beans; and iron and zinc enriched millet, rice, and wheat are being produced for Asia. In Peru
potatoes are being developed at the International Potato Center in Lima to contain more iron and zinc, also without genetic modification.
Burmese Rice Planting © David Kerkhoff via iStockphoto.com
Green Super Rice is actually a number of new rice varieties that are being conventionally bred to maintain high crop yield with less fertilizer and in unfavorable environmental conditions. A
Bill and Melinda Gates Foundation-funded rice research project, these rice crops are being targeted to poor rice farmers in fifteen countries of Africa and Asia. These strains can be tailored to the individual needs of a region, such as drought or flooding. The ability to produce these varieties is dependent on molecular genetics and a detailed knowledge of the genes under study. A
key technique involves subjecting biotic and abiotic stresses to offspring, thereby eliminating weak lines in a system of accelerated natural selection.
In a further example, a salt-tolerant wheat that yields 25 per cent more on saline soils than its parent variety was created by placing salt tolerant genes from Triticum monoccum, a wheat species that grows on poor, arid soils in the Middle East, into durum wheat. This was accomplished using non-GM breeding. Successful offspring were identified using the latest molecular marking technology.
“Site-directed mutagenesis,” is a technique that is currently lead by Cibus, a company in San Diego. This uses the plant’s own genetic machinery to change its DNA. Regulatory approval is more straightforward because outside genes are not being introduced.
Cibus has reached agreements with a variety of companies and organizations to use its technique on their crops, including the Flax Council of Canada. Although this is still genetic modification, it may be tolerable to a public that fears “Frankenfoods” because altered genes are sourced from the plants’ own genetic armamentarium.
Genetic technology remains vital even in the conventional production of new crops. Writing in the Proceedings of the National Academy of Sciences (PNAS) in 2009, researchers
stated: “……the best biofortification strategies will likely involve genetic engineering in conjunction with conventional breeding, particularly when the direct enhancement of local elite breeding varieties is required.”
The use of a GM versus a conventional crop must be considered on a case by case basis. If financial gains are to be made by the farmer, the GM crop will be selected, and not always to the benefit of the future of farming. This is human nature. Scientific research must be independent of big business and must indicate when GMOs have gone wrong, no matter their temporary financial advantage. Then they must be removed from the marketplace.
Genetically modified crops should not be used to the exclusion of conventional crops, particularly if their use is being driven by financial gain on the part of big business. If conventional methods provide seeds that breed true from generation to generation and have viable traits that ensure a healthy and productive crop at a cheaper price, then they are superior and should be promoted. In addition to biotechnology, viable, informed agro-ecological practices are critical. GMOs alone do not guarantee a successful crop.
The Problem of Feeding the World Perhaps the most highly touted positive outcome of GMO crops is in the fight against world hunger and malnutrition. We have already seen in Part 2 of this series how genetic modification is being geared towards nutritional augmentation of crops as well as towards improved yield in areas of highly challenged soils and climate. While conventional breeding programs are making significant contributions as well, the role of genetic modification should not be overlooked.
In Europe there is a pervasive resistance to genetically modified food. Because of the European influence throughout Africa and lack of education there on the role and benefits of GMOs, Africa has been very slow to implement planting of genetically modified crops. Activism against GMOs has played a significant role. Since regulatory laws are strict in Europe, this has influenced progress in Africa with which it has strong ties. It would seem that this can only prolong the problems of starvation and malnutrition in the region. Recently, Roger Beachy, head of the National Institutes of Food and Agriculture of the USDA,
spoke out pointedly on this subject. Europe cannot keep influencing third world countries in this way because the cost is lives. A unified effort that seeks a role for GMOs, particularly in areas of the world that rely on a single crop for food, is critical. World support for integrating these products with modern agricultural technology must occur, however, as small farmers often do not have access to modern seeds and other technological advantages, even if they should want them.
Since 1980, U.S. assistance for agricultural development in Africa has fallen by 75%.
Greenpeace has been persistent and ferocious in its protest against GMOs. It apparently funded the study of Spiroux et al. that claims toxicity of Bt and Roundup Ready corn fed to rats; this paper was based largely on statistical analysis of previous studies by Monsanto. The results of the paper have been grossly exaggerated across the internet as “organ failure” in rats. The small biochemical changes observed did not correlate with organic disease.
Food Standards Australia New Zealand, among several organizations, has refuted the conclusions.
Greenpeace creates a picture of GMOs interbreeding wildly throughout nature, and thus creating an “unforeseeable and uncontrollable” future.
In reality genetically modified organisms have been part of the food chain for 15 years and have yet to create any scientifically proven illness. True, there is no absolute proof that GMOs might not cause some health effects somewhere eventually, but it is easy to scare the public with such hints of the bogeyman to come. How is this fair to areas of the world that can seriously benefit from GMOs?
Greenpeace is right to state that biological diversity is important as part of our “global heritage.” Monocultures are more susceptible to disease, as has occurred with commercial bananas and oranges. (See earlier part) Diverse varieties of heritage plants serve as a source of important material for naturally and genetically modified crops that will resist diseases as they emerge and facilitate production of novel, improved food crops to nourish the world. But diverse plantings, often important in small family farms, cannot be adapted to large scale production, and it is large scale production that is needed if our exploding world population is to thrive. We cannot expect our poor world neighbors to survive on boutique produce, grown organically on small farms. That is food elitism.
Further, regulatory delays, like those faced by golden rice, are unreasonable. It is unconscionable to hold a nutritionally-modified organism to the same cookie cutter of fierce regulatory requirements that might reasonably face a GMO that is herbicide or pest resistant. It is time for a two-tiered system with fast tracking for simple nutrionally altered GMOs that improve protein, vitamin, and trace mineral content of food, while providing a more rigorous approval process for GMOs involving pesticides, herbicides, and resistance to infectious diseases.
The rich can afford to be cautious, even if caution were due. But the poor cannot continue to face starvation and malnutrition with its attendant diseases when part of the answer lies at hand. From
Jimmy Carter: “
Responsible biotechnology is not the enemy; starvation is. Without adequate food supplies at affordable prices, we cannot expect world health or peace.”
No one likes to give an inch on any highly polarized issue: look at the NRA, which does not support a ban on automatic weapons and vehemently holds on to the right to purchase a gun without a background check. As long as we see GMOs in terms of black and white, we cannot make progress to fight malnutrition and starvation, to provide a cheaper source of medicines and vaccines, to address genetic diseases, and to fight problems of pollution and energy shortage. Let us approach this vitally important field of technology with insight, thoughtfulness, and an open mind.
So it's Marzie here, with still more homework...
If you lived in Africa or Latin America and could eat potatoes or some other tuber that would prevent your susceptibility to malaria or dengue, so that you could be healthy enough to work and feed (and also protect) your children, so that you could avoid the costs, even if you could somehow afford them, of medical care for one of those mosquito borne diseases-
Would you?
Syringe stuck in a potato ©David Crockett via iStockphoto.com
You bet you would.
I'll be back with more about GMOs next week. So many of you had no idea of the good side of GMOs, or where the ideas that GMOs are bad came from. I'll be hoping to add to the broad perspective that Thelma Lee has built. As always, thanks for reading...
Article text content © Thelma Lee Gross, DVM
Blog end comments © Bright Nepenthe, 2011
All other images were purchased from iStockphoto and/or are fair use via Wikipedia as noted.
© Bright Nepenthe, 2011
