Author: Larissa Parsley
Date: July 2004
Figure 1. Plant cloning through tissue culture propagation. One of genetic engineering's most powerful tools, cloning results in a "replica" of the original organism. In this diagram, a plant is shown being cloned by isolating its root cells and allowing them to grow in a nutrient-rich culture. The root cells will de-differentiate into calluses, or masses of non-specialized cells. These calluses can then be exposed to various plant hormones, stimulating them to grow and eventually develop into plants similar to the original plant. (Source: www.science.howstuffworks.com)
What once was a quick stop at the local grocery store now has become a series of carefully planned purchases for many consumers. All around, signs proclaim "organic" and "all natural" descriptions that, in the past, applied to all foods found in the grocery store. What products warrant so much attention and demand so much purchasing consideration? Fresh fruits and vegetables, which used to be chosen based solely on cost and appearance, are now subjected to a new criterion: have the plants been genetically modified in any way? If so, how does this affect consumers and their purchasing choices? What advantages and risks come with genetically modified plants? Do government agencies have a responsibility to regulate the production and labeling of genetically modified plants? Answers to these questions are inherently complex and can only become clear once an understanding of genetic modification is reached and the major issues of genetically modifying plants are addressed in an objective manner.
Genetic engineering 101:
When words like "genetic engineering" enter the conversation, some minds tend to jump to conclusions, conjuring up images of an army of cloned Hitlers, a dog with two heads, or purple corn on-the-cob. However, a genetically engineered organism (often referred to as "genetically modified") more than likely has undergone very little change in terms of its genetics. In the realm of food and medical biotechnology, a plant or animal is affected by genetic engineering in three possible ways:
1. Certain genes of the plant or animal are altered. These genes may be "turned on" or "turned off" to control the expression of certain traits in the organism.
Figure 2. Antibiotic-resistance marker genes. A gene that will confer antibiotic resistance to the plant is included in the same vector containing the gene which will give the plant its new, desired characteristic. If the plant exhibits antibiotic resistance, it can be deduced that the plant will also exhibit the new characteristic. (Source: BBC News)
2. A clone of the plant or animal is produced. Using cells from the host plant or animal, a clone is allowed to develop which is genetically identical to the host.
3. New genetic material (DNA) is introduced into the genome of the plant or animal. Genes from an organism of a completely different species may be inserted into the plant or animal's genome to confer new characteristics on the plant or animal. This method of genetic engineering is known as transgenic modification, and the organism is now said to contain recombinant (a new combination of) DNA. When plants are genetically modified for food or medical purposes, the third method of modification is most common.
Although transgenics is a relatively new modification technique, the manipulation of plants to achieve certain traits or crop yields is not so new. Since prehistoric times, farmers and gatherers have used selective breeding to create hybrids of plants or to produce healthier versions of a weaker plant. In more recent years, as our understanding of genetic expression control deepens, our methods for manipulating an organism's characteristics become increasingly more technical and specific.
The world was introduced to its first commercialized, genetically modified plant in 1992, when the biotech firm Calgene marketed its FlavrSavr© tomato. Because of its genetic modifications, this "new and improved" tomato resisted ripening and remained firm much longer than its unmodified counterpart. That same year, the U.S. Food and Drug Administration (FDA) announced that genetically engineered foods are "not inherently dangerous" and therefore require no special regulation.
The FDA's assurances surrounding the safety of genetically modified foods may have placated consumer concerns 11 years ago, but new health risks, economic effects, and ethical concerns are on the rise in the minds of many consumers. The question not only remains but inherently demands to be answered: What are the benefits and dangers of genetically modifying plants, and do these benefits ultimately outweigh the risks involved in such a manipulation of nature?
Advantages of genetically modified plants
Most genetically modified plants (GMPs) are crops that are modified to improve food quality or production, such as Calgene's tomato. Enhancing taste, appearance, and shelf life of certain crops has obvious economic benefits for the consumer, and although consumer satisfaction is a very positive aspect of GMPs, there exist many additional, wide-reaching advantages as well.
Some genetic modifications are designed to improve the quality and quantity of crop yield of a particular plant. For example, a corn plant may be engineered in such a way so as to generate a certain protein that increases the efficiency of its growth cycle, therefore producing more corn in a shorter amount of time than the traditional corn plant.
Another method of increasing crop yield is to confer resistance in plants normally damaged or destroyed by insects. A genetic modification may result in a new color pigment in the plant's leaves that wards off previously persistent insects, so that the plant is allowed to develop normally into a healthy source of food. A similar method of protecting crops involves genetically instilling herbicide tolerance and pesticide resistance in plants that farmers want to remain unaffected by such chemicals. If a weed-killing herbicide also harmed a farmer's wheat crop, genetic modification could confer herbicide resistance in the wheat so that it would be unaffected by the herbicide meant to destroy the weeds.
Figure 3. Recent public opinion concerning mandatory labeling of genetically modified foods. From 1998 to 2001, there was an 11% increase in public support for mandatory labeling. This steady increase demonstrates a growing public concern and consumer desire to know what types of food are being purchased and eaten. (Source: Americans & The World: Public Opinions on International Affairs)
An increased crop yield, attained through any method, could lower costs for consumers, because a particular crop is "mass produced" with less time and labor than was previously necessary. But while economic benefits appear to be the driving force behind these genetic modifications, GMPs offer other promising possibilities in the area of medical biotechnology.
Developing vaccines and antibiotics has long been one of the most pressing responsibilities and most noble goals of medical researchers. With the help of genetic engineering, reaching that goal is becoming more realistic. In recent years, biotechnologists have developed "edible vaccines," foods that contain the power to protect against disease and must only be eaten to be effective. These edible vaccines would certainly provide a more practical method of disease control than traditional immunizations and could come at much less cost and inconvenience for the consumer. Tests are already underway to determine the effectiveness of edible vaccines against the Hepatitis B virus and for the bacterial disease cholera.
Plants also may be modified to work as "antibiotic factories," mass-producing bacterial antibiotics at a much faster rate than scientists can in a laboratory. An increased supply of antibiotics may alleviate some of the financial struggles that consumers face against high-priced medications, and these genetic modifications may also lead to the development of new and more effective antibiotics.
With our increasing knowledge of plant genetics and the techniques necessary to perform genetic modification, the possibilities seem endless. Plants can be cloned for study, be made to resist pesticides, and be modified to protect a child from contracting cholera. The economic and medical benefits are no less than amazing, but what is the price of this supposed "gift" of genetic modification?
Concerns surrounding genetically modified plants
Figure 4. Policy cartoon by Reymond Page. This image, one of many of its kind, depicts the growing public distrust and suspicion of biotech companies and their policies. In this cartoon, the artist addresses the possibility of genetic modifications modifying more than the scientist's intended target and the seemingly casual manner in which organisms are modified. (Source: Action Group on Erosion, Technology, and Concentration)
Ironically, many of the economic and medical advantages associated with the genetic modification of plants are considered to be the biological disadvantages of the same process. While many consumers are hesitant to embrace GMPs for personal, philosophical, or religious reasons, legitimate health and ecological risks do arise when a plant (or any other organism) is genetically modified.
When a plant receives an infusion of foreign DNA that introduces a new trait, the plant also receives a "marker gene," an extra gene biochemically linked to the foreign DNA. This marker gene is incorporated into the plant's genome along with the foreign DNA and codes for another trait often more quickly and easily recognizable than the trait from the foreign DNA. In this way, scientists can confirm that the plant successfully received and incorporated the new DNA without waiting until the plant completes a growing season. Often, this marker gene codes for a type of antibiotic resistance in the plant, a trait easily tested soon after genetic modification occurs. If the plant shows resistance, then the modification was successful, and the plant should exhibit the desired trait.
This quick test comes with an inherent risk, however; many health officials are concerned that the plant's antibiotic resistance gene might be transferred to bacterial cells in the human body after the plant is ingested. If this transfer occurs, bacteria in the body could become resistant to the selected antibiotic and therefore become a potential public health concern.
The transfer of pollen between modified and non-modified plants could also create health and ecological problems involves. It is possible for recombinant DNA to be incorporated into an unintended host during pollination. Controlling the spread of engineered genetic material to plants that were never meant to be modified poses a deeper question: Can we realistically and effectively control genetic modification so that biodiversity is maintained?
Many consumers also have concerns regarding the transfer of allergens in GMPs. The severe allergic reactions associated with peanuts and other nuts could become a health risk with new, genetically modified plant varieties. A strawberry plant that previously provoked no allergic reaction in an individual could, after genetic modification, result in a new and never-before-seen immune response.
Taking a step back from the health and biology of the situation, economics accounts for a significant disadvantage in the minds of the GMP-wary. While supporters of GMPs claim that the increased crop yield can help provide food for developing countries, many organizations feel that these countries will never see this surplus of food because it is not in the economic interest of the companies that produce it. Anuradha Mittal, a co-director for Food First, a non-profit food policy group based in Oakland, California, questions how a biotech takeover of food production could possibly benefit the farming community and developing countries: "How can corporations expect farmers to believe this technology is in their best interests? It's about maximizing corporate profits, not ending world hunger."
Indeed, valid health, ecological, and economic risks exist with regards to genetic modification. However, there is always more to the story. If the controversy surrounding the use of GMPs centered only on safety and economics, the decision to support or reject GMPs would simply be a matter of weighing personal benefits against personal risks, for example asking whether the transfer of antibiotic resistance an acceptable risk if that same technology could provide a vaccine against HIV. However, most consumers have more than safety and economics on their minds when they consider genetic modification, and these additional considerations cannot be so easily addressed.
A deeper controversy: Social and ethical concerns
Figure 5. Wheat blows in the wind. The visual similarities between modified and non-modified crops make it impossible for the consumer to detect any modifications without seeing a label that describes the food as modified. Consumer trust is simply one of many facets to the controversy surrounding genetically modified food and the labels that might accompany such food.
Before a genetically modified product can be released onto the public market, it must pass a test of "substantial equivalence," a term that refers to the relative safety of the new product as compared to its traditional counterpart. If the new product is found to be as safe as or safer than the traditional product, then it is declared to be "substantially equivalent" and can be commercialized without any special regulation. For the consumer whose main concerns about GMPs lie in safety and health, this equivalence test may provide some comfort.
However, most consumers have doubts about GMPs on a less easily defined level. In addition to the substantial equivalence test, companies and regulatory agencies consider three main criteria when evaluating a new genetically modified product: efficacy, quality, and safety. It has been often noted that a fourth criterion unofficially exists: morality. Ironically, this criterion, more so than the other three combined, often dictates what action the company or agency will take with regards to marketing the product.
Many consumers are hesitant to support a science that they believe is "playing God" with nature. Other consumers, either for religious or personal reasons, may want to avoid eating plants which contain bacterial, animal, or human genes and believe that such plants should not be allowed to enter the human food chain.
Although many consumers do make informed decisions concerning GMPs from a health, economic, or even an ethical standpoint, at times a lack of familiarity with the process of genetic modifications and its affects leads to a suspicion which makes an objective decision difficult. Consumers' doubts about GMPs may simply arise from a fear of the unknown and a distrust of the scientific community which does not always clearly communicate its objectives and methods to society.
So, what will it take to alleviate health and safety worries in the minds of the consumers? One possible solution, which is, ironically, a new controversy in itself, is being explored.
Labeling: Will it solve the problem?
At the local grocery store we are faced with a purchasing dilemma: as the "organic" and "all natural" signs are displayed around us, we wonder, "Are all of the products without these signs genetically modified?" If so, how have they been modified? If you were a consumer in this grocery store, would you want to know that the fruits and vegetables you are buying have undergone genetic modification?
Most consumers would answer "yes" to this question, which sparks yet another controversy that is not easily resolved with equivalence tests and FDA research reports. Biotech companies have displayed a long-standing opposition to the mandatory labeling of their genetically modified products, citing time, manpower, and finances as limiting factors. Consumers, on the other hand, often feel that this unwillingness to label demonstrates secrecy and unethical motives on the part of the company, which only magnifies the distrust and suspicion already harbored by many consumers.
Companies argue that labeling for health and safety purposes would not greatly affect the consumer's purchasing choice because products such as cigarettes and alcohol are clearly labeled with health warnings yet are purchased constantly, seemingly without reservation. However, the fourth criterion of morality once again enters the picture: many consumers feel they have a right to know what products have been genetically modified so they might avoid them for religious or ethical reasons. For example, a vegetarian may choose to abstain from eating a fruit which contains animal genes, or a religious group may want to avoid genetically modified products that contain genes from an animal they consider to be sacred.
In addition to moral and ethical concerns, the simple matter of safety is reason enough for many consumers to demand labeling. Even if a particular food has been deemed "safe and healthy" for public consumption by a government research trial, the consumer may still have reservations with regard to his or her personal health. Robert Thiel, Ph.D., N.D., president of the Neuropathic Medical Association at California State University, warns that government agencies may be reluctant to enforce labeling because they believe a GMP is not fundamentally different than its unmodified counterpart. "The FDA currently requires no labeling because it believes that genetically modified foods are not significantly different than hybrids developed by cross breeding. Genetically modified foods are different, however, from hybrids." This differentiation, which appears to stem from academic hair-splitting, is truly fundamental in the labeling controversy. As Thiel states, "There is phenomenal potential for harm."
The clear and appropriate labeling of such products must become a reality before the consumer market as a whole can begin to accept the role of genetically modified organisms as a source of food, medicine, and other everyday products. When labeling becomes as common as genetic modification itself, consumers will then be free to exercise their choice about this issue, not only with words, but with purchasing action. "The mere fact that labels are there changes consumers' perception of risk from one that is involuntary to one that is voluntary," concludes Lydia Zepeda, an associate professor of consumer science at the University of Wisconsin-Madison. "Once you have a label that's assured by a government agency, there's a lot of trust in that. Some agreed-upon standard will end up enhancing consumer confidence."
Transgenic plants: Have they truly taken root?
It's clear transgenic plants are here to stay; however, must the controversy stay along with them? Don Glickman and Vin Weber, advisors to the Pew Initiative on Food and Biotechnology, answer with an emphatic "no." "Rather than fight about whether the biotech genie is good or bad," they say, "all parties need to sit down and collectively figure out how to manage it." The controversy appears to be as detrimental to the public as any risk associated with the genetically modified plants themselves. Glickman and Weber pose a warning aimed at the destructive international effects of a continued controversy. "Without efforts to find agreement, we risk wrecking the current round of trade negotiations, increasing the schism between the European Union and the United States, and impeding the use of a technology that has such great promise for the future." This schism refers to the strained relations between the EU and the United States with regard to the regulation of genetically modified organisms. The EU maintains stricter standards for labeling GMPs and also for the tracking of foods that may contain modified ingredients. Because of these regulatory differences, conflict often arises when GMPs are transferred between the EU and the United States.
The advantages and risks associated with genetically modified plants are easily explored, yet closure or compromise on the issue seems infinitely far away. What must be examined more closely are the underlying issues that compound the controversy, such as ethical concerns and labeling. These issues are not likely to disappear; however, neither is the science of genetic modification. Companies will emphasize the benefits of GMPs while consumers will question the health and ethical risks involved. Companies will downplay the importance of labeling while consumers will demand to know the genetic nature of the products they buy. However, transgenic modification has indeed become a way of life in the biotechnology world, and the techniques involved are becoming more specific and effective every day.
What is the bottom line? Genetically modified plants are here to stay, but perhaps the next time you look around your local grocery store, you might look at that ear of corn a little more closely and consider the issues surrounding such a seemingly innocent source of nourishment.
Further Reading
"History of Genetically Modified Organisms (GMOs)." American Radio Works.
"Transgenic Crops: An Introduction and Resource Guide." Colorado State University.
"Bioengineered Foods: Will They Cause Allergic Reactions?" U.S. Food and Drug Administration.
"Report on Consumer Focus Groups on Biotechnology. U.S. Food and Drug Administration.
Smith, John E. "Public Perception of Biotechnology." Basic Biotechnology. Eds. Colin Ratledge and Bjorn Kristiansen. Cambridge, UK: Cambridge University Press, 2002. 3-16.
Gaskell, George, et al. "Worlds Apart? The Reception of Genetically Modified Foods in Europe and the U.S." Science (25): 384-387. 16 July 1999.
Peter Pringle. Food, Inc: Mendel to Monsanto The Promises and Perils of the Biotech Harvest. New York: Simon & Schuster. 2003.