Foods from Biotechnology in the Marketplace: Untested? Unlabelled?
Peggy G. Lemaux
Department of Plant and Microbial Biology
Claims are often repeated by those opposed to biotechnology that the products produced commercially are ÒUntested and UnlabelledÓ. The focus of my talk will be to explore these claims by looking at these products and discussing some of the issues that have surfaced relating to safety and utility.
First it might be helpful to look at the clear differences in attitudes between U.S. and European consumers and why these differences might have occurred.
There is no simple explanation. The differences began to surface in the late 1990Õs with some rather strong outcries from Europe. Why did it happen then? About that time there were several food safety scares in the E.U., e.g., mad cow disease and dioxin-contaminated foods. The credibility and effectiveness of the regulatory agencies during and after these events was, I believe, an important factor in the decisions consumers made about GE foods. Consumer confidence in the ability of the agencies to insure food safety eroded. Decisions by officials were perceived by many to be based on political expediency rather than on public safety concerns. There were also other factors that contributed to the controversy.
á Involuntary nature of change: Why werenÕt we told we were eating these foods?
á Cultural differences: We like our foods just the way they are!
á Economic incentives: European farm subsidies are the highest in the world.
How Do U.S. Consumers Feel about the New GE Foods?
These factors in Europe certainly influenced the attitudes of E.U. consumers. But how do U.S. consumers really feel about them Ð then and now? First it is important to know that even as late as April 2003, when asked if there "are any foods produced through biotechnology in the supermarket now?" 34% of U.S. consumers said ÒnoÓ. This number, 37%, differs little from that from a survey done in 1997 (IFIC, 2003).
Perhaps this lack of interest in what Europeans consider an important food safety issue relates to the fact that the majority of U.S. consumers maintain trust in federal agencies to assure food and environmental safety. Consumer polls indicate that respondents have confidence in the U.S. Food and Drug Administration, the regulatory arm responsible for food safety and the agency that monitors the safety of the new GE foods. In a recent Gallup poll, 75% of Americans had either a great deal or a fair amount of confidence in the federal government to ensure food safety; only 5% had no confidence.
This confidence is reflected in the fact that only 9% of those polled expressed concern about genetically engineered foods in terms of safety issues, down from 19% who expressed that concern in Jan. 2001. Of much more concern were safety concerns related to food handling and preparation, where 41% of those questioned expressed concern.
Perhaps this confidence also spills over into attitudes about labeling. In the April 2003 International Food Information Council poll, 70% of those polled either expressed support of the agencyÕs policy related to labeling (after the policy was described to them) or did not oppose it. In fact when asked if there was any information not currently on food labels that they would like to see on labels, only 2% of the population mentioned Ògenetically engineeredÓ and that number has remained constant since Jan. 2001.
In the U.S. there is, however, much debate over the role of the federal and state government in mandating labeling of the new GE foods. The debate revolves around the consumer Òright to knowÓ issue, not food safety. Agencies must grapple with the dilemma of who should pay the costs for providing this information to interested consumers. Since the government agencies are mandated to address food safety, not food choice issues, requiring labeling of GE foods is not a straightforward decision. This is because public perception of the health risks of consuming the new GE foods is inconsistent with the view of most health professionals and scientific experts.
What Are the Issues?
So what are some of the issues surrounding the application of genetic engineering technologies to agricultural crops? In general they fall into three broad categories, food safety, environmental and socioeconomic/ethical issues. It is not possible to discuss all the issues that fall into these categories since there are many. And it might not even be possible to address those of importance to you personally since what is vastly important to one person or group of people may not be of concern to others.
In entering into this discussion, it is important to consider the following. There are differences between ÒriskÓ, Òperception of riskÓ and ÒsafetyÓ. Risk per se can be determined quantitatively while perception of risk is something decided by an individual based on his/her own interpretation of the value of the scientific information. ÒSafetyÓ is acceptable risk. The corollary to this is that most applications of technology are not black and white issues; there are plusses and minuses to most all of them. For example, air travel does involve some quantifiable risk, but some individuals consider it safe and are willing to accept the risks, based on the benefits. In our technologically complex world, this can be said of many, if not all, activities in which we engage.
What are some of the issues related to food safety?
1) Introducing Allergens. An oft-cited example of the potential for this risk is some work conducted at Pioneer Hi-Bred to improve the protein quality of soybean. The initial approach to this problem was to use a naturally occurring protein from Brazil nut, which compensated for the amino acid imbalance in the soy nut. During the development of this product, however, Pioneer scientists checked reactivity with human sera and discovered that some individuals had allergies to this protein. Work on this project was then terminated.
Does this example show that it is possible to introduce an allergen into a food? Yes. Is this a surprising finding to most scientists? No. This example does show that the development process for a GE food involves steps that allow a company to discover a food safety problem before the food is marketed.
Since we are talking about risks and benefits, it should also be noted that biotechnology could be used to eliminate allergens. This approach to increasing food safety has not yet been fully explored, but at this point certain proteins, or building blocks of food, that cause allergic responses in humans and certain animals can be identified. Once that is accomplished, it is then possible to engineer a food to eliminate these proteins. In China, where rice is a major allergenic source, researchers identified a major allergen and worked to create rice varieties that had reduced levels of the protein and were less allergenic for consumers. In the U.S. work is proceeding on the removal of allergens from for example wheat, peanut and milk.
What U.S. governmental agencies are responsible for overseeing the potential for allergenicity in GE foods? First, if a piece of genetic information is introduced into a GE food from a source known to cause allergies, e.g., peanuts, wheat, fish, milk, the product must be, as mentioned earlier, labeled as such under current FDA statutes. Second, companies under FDA scrutiny do extensive testing of the GE foods to assure safety, as occurred with the Brazil nut protein case. This testing involves assessment of potential allergenicity using predictive models and methods and, if necessary, conduct animal model testing. Such testing does not result in zero risk, but it does reduce the probability of adverse consumer reactions.
Another example of an allergenicity problem related to GE foods involved Starlink corn, which contained a protein designed to protect against insect damage. Because of questions regarding some of its characteristics, federal regulatory agencies approved it only for animal feed, not for human consumption. Some of the grain got into certain corn products, which were recalled because agencies were not convinced that this new protein was allergy-free. Was this a danger to consumers? No, allergists know that a person has to eat a lot of a protein over a period of time to develop allergies and this product was removed from the market before that could happen. Subsequent studies show that this protein had only a moderate chance of causing an allergic response. Did the presence of Starlink corn in food products show that there were weaknesses in the grain movement process? Yes, this demonstrated that grain destined for only animal consumption could not be effectively segregated from grain intended for human consumption. This was an important lesson to learn before plants producing pharmaceuticals or plastics enter the market.
2) Inadvertent Creation of Allergens or Toxins. Can we predict or assess this type of situation with 100% accuracy. No. But, is this a situation that would only occur with GE foods? No. For example, the development of both new celery and potato varieties by classical breeding has led to foods with high levels of phytotoxins (psoralen and glycoalkaloids, respectively). When this was discovered during routine testing, development of these varieties was stopped, just as in the case with the Brazil nut protein in GE soy. Another slightly different example is the kiwi, which was introduced into the U.S. in the late 1960Õs. This fruit was later found to cause allergies in certain individuals, which in some cases has proven fatal because of unexpected cross-reactions with latex rubber allergies in patients with kiwi allergies. Although this danger is present, kiwis have not been removed from the market; individuals simply have to learn to avoid the allergenic products. Should foods like the kiwi undergo a decade or more of testing to insure that such allergenicity problems do not occur? A difficult question..
One might then ask if the probability that an unexpected allergen will occur in a new GE food higher than it would be with a food created by, for example, classical breeding between wild and commercial species? In my opinion, no. It is no more likely that the insertion of a new gene at a random location in the plant genome would activate some previously unforeseen compound than that it would be to occur during the random rearrangements and movement of genetic material during a classical breeding cross. So although the risk is not zero, it is no greater than with conventional breeding techniques, such as occurred with celery and potato, and with which we have a great deal of experience and confidence.
3) Changing Nutritive Content. To date, there is little published data to support this occurrence. One example raised relates to differences in the levels of certain secondary compounds in GE soybeans compared to the same compounds in non-GE varieties. The difficulty with such comparisons is that there is a lot of inherent variation, making comparisons difficult. For example, if one took non-GE soybeans from one field and compared them to non-GE soybeans from another field grown under different environmental conditions, they would be significantly different with regard to the secondary compounds. Biological systems are not like computers where the outcome of a particular application is the same regardless of the type of day on which you do the procedure.
Companies conduct extensive testing to demonstrate substantial equivalence, looking at many different nutritive parameters, for example, protein, fat and CHO content, minerals, vitamins, fats. The values obtained for the GE food must be in the same range as in the non-GE variety. These tests are conducted numerous times on numerous samples to average out environmental variation. Nonetheless biological variation will exist and influence the outcome.
As for the example of creating versus eliminating allergens, the same argument can be made for nutrient content. Genetic engineering can be used to improve the nutritional quality of foods, increasing the types and amounts of amino acids, changing the fat profile, and augmenting vitamin or antioxidant content. One example carried out by Indian scientists involved increasing the protein quality and quantity in potato by introducing a nonallergenic protein from Amaranthus.
4) Spread of Antibiotic Resistance Genes and Horizontal Gene Transfer. Consideration of this issue requires generation of sufficient scientific data to assess the issue. What is horizontal gene transfer? In this case it means the transfer of genetic information from foods to other organisms, like bacteria and humans. Some data related to this point has been published in the scientific literature. First, during the process of digestion most proteins and DNA from foods are broken down. Analysis of experiments in which rats are fed large quantities of DNA indicate that, although the genes can reside transiently in the outermost cells of certain organs like the liver, their retention is not stable and has no observable consequences. After all, such processes have been happening during the entire time humans have been eating foods and their DNA and few of us have taken on characteristics of the foods we eat!
Second is the concern for transfer of antibiotic resistance genes in GE plants to gut bacteria. While this has been shown to occur at very low rates under certain unusual circumstances, this is not likely to result in problems. Most antibiotic resistance genes are not effective against antibiotics in current clinical use and the use of these genes to generate GE plants is being phased out. Does this mean it is zero risk? No, but it means that it is not likely to be a significant problem. That antibiotic resistance in gut bacteria is a worldwide problem is irrefutable, but the most significant causes of this problem are due to animal husbandry practices and indiscriminate use of antibiotics in human health. The likely impact of the presence of antibiotic resistance genes in the new GE foods, if it occurs, will be negligible. One should not ignore the issue, but it is important not to lose focus on issues that are more critical in addressing the problem.
Environmental Issues
In the arena of environmental issues, there have been numerous questions raised regarding the safety and desirability of GE crops.
1) Unintended effects on insect or pest populations. This issue first arose with the well-publicized Nature paper on the effects of certain Bt corn pollen on Monarch butterflies. In this paper, the work was conducted in a laboratory study where the fate of larvae were studied after being fed either leaves dusted with pollen from control, Bt- or non-Bt-containing corn; the insects were not offered a choice of diet. Analysis of data show that larvae consuming Bt pollen were more adversely affected than those that did not.
This result was not surprising to scientists since the particular Bt used is known to affect this type of insect larvae; however, there are some other considerations in determining just how significant a problem this might be. First, the single GE event used contains Bt in the pollen; other events do not. In the case of the studied event it was possible to create a construct that did not express insecticide in the pollen and the Nature study pointed out the fact that this should have been done.
But, was this really a significant threat to the Monarch butterfly? A large-scale study was conducted to assess this. First it was found that pollen shed in most (not all) areas of the country does not occur at the same time that larval feeding occurs and pollen viability in corn is only about 48 hours. Second, Monarch butterflies prefer to lay their eggs on milkweed (their preferred host) in the open, not those plants located in the middle of a cornfield. Lastly, the density of pollen needed to adversely affect the larval eating would occur only within ~9 feet of the edge of the cornfield.
Does this mean that Monarch butterfly larvae would not be affected by Bt corn varieties that express the protein in the pollen? No. Does this mean that this is not likely to be a major threat to Monarch butterfly populations? Yes. Does it mean that we should not be concerned about such secondary effects of pesticidal strategies? No, just as we should be concerned with the environmental effects of other strategies, like pesticides, used to control pests.
Is it true that companies and others had not studied effects on unintended pests before the introduction of the varieties? No, extensive testing occurred that included assessments of six unintended pests, including the lacewing; however, the Monarch was not among those. tested but that it had an effect could have been predicted by most scientists with knowledge in the area. The question for many is the relative effect of the Bt strategy on Monarchs and other unintended pests versus conventional strategies.
An interesting contrast to the Monarch butterfly story, that once again emphasizes the need for risk/benefit analysis, is another less well-reported study also published in Nature that demonstrated a positive effect of Bt on beneficial insects. In this case they looked at the effects of Bt canola on a parasitic wasp that infects a major canola pest, the diamondback moth. This study found that the populations of the beneficial parasitic wasp rose in the areas that had Bt canola, probably due to the decrease in pesticide use that otherwise reduced the wasp populations.
But the assessment of impact does not stop with these studies. Other issues to be addressed are the impact of these gene products on the surrounding environment, the sexual compatibility with plants surrounding the production field, the consequences of the transmission of the trait to compatible relatives. One of the problems in interpreting such data is the issue of to what these impacts are to be compared. Should the Bt corn be held up against a zero-risk paradigm where agriculture has no effects on the environment, to the methods used by production agriculture or to the practices of organic agriculture? Much of the debate, I believe, has to do with what one chooses for the comparison.
2) Creation of Weeds Resistant to Herbicides. Is there a possibility of creating such weeds that are resistant to the herbicides being used for the herbicide tolerant (HT) crops? This has already happened; in fact it has been documented in several places in the U.S. and Australia. This proves once again that overuse of a particular pesticide can render a new chemical or technology useless? Will this situation create an ecological disaster? In my opinion, no. Other, perhaps less environmentally friendly herbicides, can be used to control the weeds, but it will be a significant problem for the companies developing the crops and farmers will lose the flexibility to use them!
3) Movement of Genes to Other Plants. Could the passage of genes from GE crops to weed species lead to the development of a ÒsuperweedÓ, one that does not respond to most herbicides? Certainly the passage of genes from plant to plant will happen. In the U.S. the major crops like soy, corn and cotton do not have wild relatives, but other crops like canola, sugarbeet, sunflower, rice and oats do have wild relatives and in some cases these relatives are control problems. So is it possible that a trait could escape? Yes, it is likely. Could this be a problem? It is dependent on the trait and what characteristic it confers on the wild relative. In the case of red rice, for example, this species is a problem for rice growers. The movement of herbicide tolerance to these varieties would make it impossible to control red rice with the herbicide used against the plant with the resistance gene. But returning to practices used before the introduction of these varieties could control the problem. Again is this likely to be an ecological disaster? No. But it would be a problem for farmers and for the companies developing these varieties. Therefore it is something we should be concerned about and attempt to control?
The potential impact of the movement of a particular gene should be judged on a case by case basis. In areas of cultural diversity, such as in some developing countries, crops with certain traits probably should not be released. Or the plants should be engineered so they donÕt pass the trait on to wild relatives, by creating male sterile plants or putting the trait in the chloroplast genome, which slows the rate of movement to other plants. An example of genes escaping in an area of cultural diversity was raised by a study published again in Nature. Here an engineered gene was reported to have escaped into the landraces of corn in Mexico, an area of cultural diversity for this important crop.
Another possible impact of gene movement involves the passage of genes to organically grown crops. In the U.S. federal policy dictated by the organic farmers themselves states that GE crops cannot be designated as ÒorganicÓ. Therefore, although genes have moved from conventional crops to organic crops for years, movement of engineered genes from conventionally grown farms to organic farms can result in economic loss to organic farmers. The economic liability for this occurrence has not been firmly established.
4) Loss of Genetic Diversity. Do the use of new GE technologies lead per se to a loss of genetic diversity? Yes and No. If the introduced traits are not moved into a wide variety of germplasm so farmers can use diverse germplasm, the breadth of diversity will diminish. But the source of the problem of loss of diversity can not be placed on GE varieties alone. Current cultural practices e.g., the shifting of eating habits to include meat and agricultural practices that often involve clearing of lands, have been and will continue to be, unless changed, major factors in the loss of land, particularly rain forests, and hence genetic diversity. This issue is one of greatest concern to many environmentalists and to me personally. Once lost, we cannot regain these variant populations, which will be important to the survival of all human and animal cultures. The genetic information in many of these wild species provides irreplaceable genetic resources that must be preserved.
5) Increased Herbicide Usage. Another environmental concern relates to the potential for GE crops to have detrimental effects on the environment by increasing herbicide usage or creating long-lived residues in the soil. In the first instance, current data suggest the opposite, that in fact so far the new GE crops have not led to an increase in pesticide use in terms of active ingredient per acre. In fact in some cases, like Bt cotton, there has been an overall decrease in the use of pesticides.
While the overall usage of active ingredient decreases, it should be noted that the use of particular pesticides rises, the ones to which the crops are engineered to be tolerant. Is this a bad thing? It depends on your perspective. In general these herbicides are more environmentally friendly than many other herbicides that have been used in the past. This change in pesticide use has led to a decreased use of herbicides that have groundwater advisory warnings to 38% of the levels in 1999 over those used in 1996. But the bottom line in such reductions is whether this results in a change in the water supply. In a study conducted in Illinois, it was found that 12% of samples from conventionally grown corn contained major corn herbicides, whereas only 2% of the samples from Roundup Ready (glyphosate-tolerant) corn contained herbicides. Recently (Sept. 2003) it was reported, however, that the levels of Roundup in groundwater have increased. Probably not surprising given the increased usage of this herbicide on agricultural acreage in the U.S.
6) Other Issues. There are many other environmental issues that can be raised related to current agricultural practices including the use of the new GE crops.
á The potential for environmental degradation because of GE-crop residuals?
á Will their use lead to chemical dependence?
á How doe these questions relate to current agricultural practices, e.g., tilling, fertilizers, pesticides?
á Can the use of GE crops provide a partial solution to these problems?
á Can organic crop production provide a partial solution to these problems?
á Is it practical to utilize Òorganic practicesÓ for large scale production of foods?
á Would this lead to other economic and environmental problems?
á Does the precautionary principle, which states that a practice or a food is unsafe until proven safe, apply to any new production method when practiced in large-scale?
These and other questions are complicated and likely can not be answered with a simple ÒyesÓ or ÒnoÓ. Likely the answer is, ÒIt dependsÓ. The answer emerges only as additional research is done and the manner in which the products and methods are deployed are set. Does this mean that the use of GE crops and the practices of organic agriculture stop until we have all the answers? That is an answer that must be decided by users, consumers and governments.
Socioeconomic/Ethical Issues
The last general category of concern involves general fears relating to economic and ethical issues. These include intellectual property rights, availability of the technology and its products in developing countries, and whether we should be involved in changes in an organismÕs genetic makeup in this manner for religious and ethical reasons. Perhaps the most universal concern is the issue of who will control the food supply and the concern over the role of multinational corporations in developing and controlling the GE varieties. These issues cannot be studied by scientific assessment but are rather issues to be discussed by economists, lawyers, companies and the public at large.
As we move toward a global economy it is no longer the case that one sector of the society can make decisions for other sectors without input. The recent problems at the WTO are a dramatic example of just how vocal groups can become when they feel that their basic human rights are being violated!
Environmentalists and other activist groups have been quite vocal in opposing the application of biotechnology to agriculture. If you listen carefully to what is said, as they articulate their concerns, it is often a fear of the unknown; we do not know enough about the technology to have a long-term view of the consequences. How can we predict the long-term consequences of consuming GE foods or growing GE crops in our fields? This caution comes about from an historical consideration of the long-term consequences of other technologies that over the long term had unexpected consequences Ð the use of fuel operated vehicles, nuclear power, and yes, DDT.
Farmers in contrast have a different view. They are the individuals to whom the responsibility of producing safe, cheap food has fallen. Their bottom line is intrinsically related to the consumersÕ bottom line. The amount of money they will pay for food determines the profit margin of the farmer. The profit margin dictates the practices the farmer uses to produce the food. To date, most improvements engineered into crop have focused on farmerÕs needs, making their jobs easier.
In some cases, farmers have found the crops improve their lots and their bottom line; in other cases, they have not. For farmers, the environmental issues raised by GE crops are not significantly different from issues they dealt with regarding conventional crops, ones that they had to manage. Given consumer support, farmers will likely embrace these technologies if they deliver benefits. If either does not materialize, farmers will return to methods used in the past. Consumers of the products will make these same judgements.
Summary
In summary, the first products of the technology are crude; improvements can be made. Many of the products currently in the fields and laboratories will not achieve the potential necessary for user or consumer acceptance. But the strategies will likely be improved and refined, just as the computer moved from a machine that took up city blocks to one that fits on your wrist. And consumer perspective on the issue may also change with time. It is likely the case that some products of the technology will find favor with users and consumers; some will not. Some will be a commercial success; some will not.
For more information, scientific references and a copy of the talk and slides, visit ucbiotech.org in the Biotechnology Information, Scientific Database and Resources sections, respectively.