Today’s CPE
The GM Food Debate
Today’s Dietitian
By Marie Dunford, PhD, RD
Vol. 6 No.6 p. 12

The headlines are eye-catching: “Frankenstein Foods,” “Cure on the Cob?” and “Are There Drugs in My Cornflakes?” These phrases may be exaggerated but the issues are real. As foods derived from genetically modified (GM) plants and animals become more common, the questions about them multiply and the debate about their use becomes more heated. As nutrition professionals, we need facts, not rhetoric. This article will present what we do and don’t know in an attempt to scientifically frame the debate.

Terminology
In the United States, genetically modified food refers to both plant and animal foods produced with the use of recombinant DNA (rDNA), which creates a new DNA molecule by splicing together two or more different pieces of DNA. The equivalent European term is genetically modified organisms. Scientific reports often use the term genetically engineered instead of genetically modified. All these terms refer to the same processes.

Biotech food may be used to describe GM food, but technically, biotechnology refers to a number of techniques of which only one is the use of rDNA.

The emotionally laden slang term “Frankenfood” is meant to convey the message that GM food is unnatural, uncontrollable, and probably dangerous. Frankenstein’s monster, we recall, was intended to be a superior human being but instead went berserk and wreaked havoc.

A Natural Process?
At the heart of the GM foods debate is the rDNA process. Simply defined, rDNA is a genetically engineered molecule containing DNA from two or more sources. Genetically engineered plants and animals typically contain DNA from an unrelated organism, such as a virus or bacteria.1 The artificially created gene is introduced into a host cell, where it is replicated.

Humans have cross-bred plants and animals to produce “better” versions for a long time.2 A most notable example is hybrid corn, which has been developed over centuries by painstaking control of pollination. Proponents of GM foods suggest that the rDNA process is simply a natural extension of cross-breeding. Critics argue that the process is not natural because genes are being moved between species and kingdoms (eg, bacteria or insects to plants), which is impossible in conventional cross-breeding.

Tester3 notes that the type of gene transfer is crucial and distinguishes between wide transfer (between kingdoms), close transfer (between plant species), and tweaking (between plant genomes from a single type of plant). Tweaking and close transfer are traditional cross-breeding processes while wide transfer is not. Theoretically, the greatest risks are associated with wide transfer.

Consumer Knowledge and Opinions
Consumer knowledge of GM foods is low. In a survey of 1,000 consumers conducted in August 2003 for the Pew Initiative on Food and Biotechnology,4 only approximately one-third of those surveyed had heard “some” or “a great deal” about GM foods. Fifty-eight percent said they had not eaten GM foods. (But many probably had. More than one-half of the food products in U.S. grocery stores are produced using GM seed or some other type of biotechnology.) In 2003, 81% of all soybeans and 40% of all corn produced in the United States was grown from GM seed.5

The August 2003 survey also found that approximately 25% thought GM foods were “basically safe” while an equal number said such foods were “basically unsafe.” Once survey participants were informed of the extent to which GM foods are already in the food supply, the number of people who thought such foods were “basically safe” increased to 44%.

Assessing Safety
The safety of GM foods has been hotly debated. Among the critical issues are the potential for allergenicity, the introduction of newly created (novel) genes, and the presence of antibiotic-resistant genes.

Nearly all human allergens are proteins. The creation of novel proteins via genetic modification raises legitimate questions about their potential to trigger allergic reactions. To be used in gene splicing, genes obtained from a known allergenic source must disprove their allergenicity as part of the safety assessment. Typically, scientists are not using genes from plants known to be allergenic, but the risk occurs because many genes are obtained from sources with unknown allergen potential, such as bacteria and viruses.6,7 Between 1999 and 2000, more than 2 trillion GM plants were grown and no adverse food reactions were reported.8

Newly created genes, known as novel genes, have small changes in the DNA sequence. As part of the normal digestion process, DNA is broken down in the gastrointestinal (GI) tract.9 Those who support GM foods suggest that the novel genes are no different than any other genetic material that makes its way through the GI tract and that humans have been ingesting the DNA of other species for centuries.6 Proponents paint the “what if” scenario. What if the novel genes that are created are different? What if a gene created from bacterial DNA was incorporated into the bacterial flora that exists in the human GI tract? That seems unlikely, but no “what if” scenario can ever be completely disregarded.

Part of the genetic modification process involves the use of a selectable marker such as an antibiotic-resistant gene. Could such a gene negate the effect of antibiotics taken by humans or animals for therapeutic purposes? Any antibiotic-resistant pathogenic bacteria in the gut would be hard to treat. Proponents of GM foods argue that ingestion of the antibiotic-resistant gene would be low and the chances slim that gut bacteria could incorporate the antibiotic-resistant gene into their DNA. This may be a moot point in the future as other selective markers are being developed, but antibiotic-resistant genes are currently part of the safety debate.2,6

Risk
Scientific perspective. The questions and scenarios sketched above all deal with risk. Scientists view risk in terms of probability—the number of events likely to occur in a given number of chances, often 10,000. Empirical data and theoretical models are used to predict the conditions that should result, resulting in a “risk factor”—say, two in 100,000. But risk assessment is not perfect and there have been unwelcome surprises. For example, the presence of mad cow disease in animals and a variant form of the disease in humans was not expected and therefore not considered when determining the risk associated with new sources of animal feed.9 Nevertheless, risk assessors try to err on the side of caution.

Sociocultural perspective. While scientists see risk as being objective and measurable, sociologists argue that risk is subjective and cannot be accurately measured. Perceived risk is powerful and often complicated because it involves unknown and potentially catastrophic outcomes. The best technical information cannot address all the concerns that may be associated with perceived risk.10

Because GM foods are new, some of the risks are unknown. If a consumer has little knowledge of DNA and genetics, the process of gene insertion may be difficult to understand. The transgenic process would not be visible in any way and any negative effects of eating the food would not be immediately obvious. Thus, it is understandable why some consumers are concerned about GM foods.

The “dreaded” effect is also present in the debate over genetic modification. For illustration purposes only, consider farm-raised fish in which a growth hormone gene has been inserted. What if the growth hormone gene affects humans two generations later? What if the farm-raised fish escape into the wild and decimate the native fish populations? Catastrophe can be easily painted on the mental canvas. “What if” plays a large role in the GM debate, and in a democracy can drive policy by passion, not scientific fact.

Trust
Part of the issue involves the degree of consumer trust in the three groups involved: government regulators, food producers, and research scientists. In the United States, the FDA, the USDA, and the Environmental Protection Agency (EPA) regulate food. The FDA is generally more trusted by consumers than the USDA, which some feel has a cozier relationship with food producers than the FDA or EPA.11 Some consumers do not understand science and technology and feel ill-qualified to make informed decisions about complex issues. They either trust the decisions of scientific experts or distrust the scientific community. Others may give some weight to scientific findings but consider nonscientific information, such as personal belief systems, highly or equally important.10 Thus, while science is at the heart of the GM food debate, economic, political, environmental, and sociocultural issues are also part of the mix.

GM foods have caused a great political divide, especially between the United States and Europe. Since 1995, food and agricultural issues have been under the purview of the World Trade Organization (WTO), whose meetings have drawn protests—sometimes over food and agricultural issues. Europeans opposed to GM foods have utilized a provision in the WTO code called the Precautionary Principle, which allows a country to set a stricter standard than that found in the WTO Codex if that country can show scientific data in support of that stricter standard. The Precautionary Principle encourages the acceptance and use of minority scientific opinions until they are disproved. Although it was originally intended for environmental issues, countries of the European Union (EU) have invoked the Precautionary Principle for GM food safety issues.11

The use of the Precautionary Principle in this way raises intriguing questions. What role should a minority opinion play? Could a corrupt or cynical minority effectively gain veto power? Without an opposing view, there would be no reasoned debate; there is much to be learned by testing the hypothesis and the null hypothesis. But a position held by a very small minority will always exist, and progress could be hampered. European resistance to GM foods that may be economic (protecting their food industries), geopolitical (surrendering to widespread mistrust of the United States), or partisan (accommodating Greek orthodoxy) could be disguised as scientifically based. When the EU countries, particularly France, asked for a ban on the import of GM seed and food products, the United States was quick to point out that the Precautionary Principle was being used as a nontariff trade barrier.12

The debate over genetic engineering, particularly GM seeds, is also a contentious environmental issue. Opponents see wide transfer gene technology as unnatural and fear a devastating effect on the Monarch butterfly (who can ingest pollen from GM corn), the loss of centuries-old native plant varieties (that cannot compete), the inability to protect against the unintended transfer of genes (a pesticide-resistant gene in soybeans might be transferred to a weed), and a harmful effect on small, poor farmers who cannot afford to buy GM seeds. For some of these reasons, certified organic farmers are prohibited from using GM seeds.

In March, voters in California’s rural Mendocino County passed an ordinance that banned genetically engineered crops and animals. It probably has more symbolic than legal value (agriculture is regulated at the state and national level, not locally), but it marks the beginning of a grassroots political effort in the United States.

A Cure for Hunger?
A highly emotional issue is the role that GM foods may play in relieving global hunger. One of the rallying cries of the proponents of genetic engineering is that to feed the predicted 9 billion world population in 2050, agricultural production will need to increase threefold. GM seeds could increase yields and reduce crop losses through pest-resistant genes13—and do it with less petrochemical fertilizers and pesticides.

Opponents argue that the root of world hunger problems is not production but poverty and food access, which are primarily economic, social, and political problems. They point out that the world currently produces enough food per capita but that hunger exists due to the lack of access to food and its limited distribution.14 This debate was made all the more real in 2002 when Zambia, a poor African country with 3 million starving people, refused to distribute tons of GM corn produced in the United States. The United Nations eventually intervened and transported the GM corn from Zambia to Malawi and delivered non-GM corn to Zambia. However, the incident infuriated U.S. officials, who claimed it was politically motivated, while European environmentalists accused the United States of trying to “exploit the world’s most effective marketing tool: starvation.”15

Nutrition
One of the strongest arguments for using rDNA technology—and one that will affect dietitians—is the opportunity to produce foods that are more nutritious. To date, the foods listed in Table 2 are not commercially available; however, some are close to introduction and all are technically possible.

The development of “supernutritious” products through genetic manipulation raises important questions: Are they safe? If they are safe, will consumers accept them? Will overall nutrition status change for better or worse? What are the risks and benefits? The questions must be asked and answered for each food, such as the following:
• Golden Rice, so named because of its light yellow color, has been modified by the insertion of beta-carotene–producing genes. Two of the genes come from daffodils and one from the bacterium Erwina uredovora. These genes contain the code for enzymes that are essential for the synthesis of beta-carotene.16

An estimated 3 million children worldwide suffer from blindness and stunted growth due to severe vitamin A deficiency; some 300 million suffer from mild vitamin A deficiency. Many of these children are in developing Asian countries where rice is a staple food. Proponents hail Golden Rice as a way of delivering a much-needed nutrient.17 Opponents argue that the bioavailability of the beta-carotene is low and that injected vitamin A (not beta-carotene) is the best intervention.18 As this is likely to be the first GM food product available to combat malnutrition, it is sure to be a political battleground.
• Lycopene-enhanced tomatoes are currently undergoing field testing. Lycopene, a precursor to beta-carotene, is a powerful antioxidant that has been associated with reduced risk for cardiovascular disease and some cancers.19
• High oleic acid soybean oil. The fatty acid composition of oil depends on the source, with olive oil being high in monounsaturated fatty acids (including oleic acid) and soybean oil high in polyunsaturated fatty acids. Using gene technology, soybean oil could be modified to contain 85% oleic acid—a substantial difference from the usual 25%. The GM soybean oil would be a highly monounsaturated fat source, even greater than olive oil. Soybean oil accounts for 82% of all the oil consumed in the United States and 27% of consumption worldwide.16

Labeling of GM Food
When seeds or foods are developed using genetic engineering, how should they be labeled? The FDA and USDA hold that genetic engineering does not make food safe or unsafe; therefore, a label should not be required. Most European countries want labeling. In an attempt to find a compromise position, the FDA proposed a new rule that would require manufacturers to notify the FDA at least 120 days before foods or animal feeds derived from GM plants are put on the market. Upon review, the FDA would issue a letter detailing regulatory status and would help manufacturers label their products for foreign markets.12

The FDA bases its position on the philosophy of “substantial equivalence.” For the purposes of regulation, if a GM food product has the same composition, nutritive value, functional characteristics, and organoleptic properties (taste, smell, and mouthfeel) as a conventional product, then that GM food is considered to have substantial equivalence.2

The argument for substantial equivalence is that genetic alterations (to date) have been minor and tightly targeted—genetic insertions involve only one or a few genes, and the plant is substantially equivalent to the original in all other characteristics.8 The counter argument is that while GM foods are equivalent in many ways to their non-GM counterparts, they differ in the most fundamentally important way: their DNA.

Currently, all GM foods on the market meet the substantial equivalence test, so the FDA does not have mandatory labeling guidelines. In 2001, a voluntary labeling document was created. The draft document took into account testimony at three public meetings and more than 50,000 written comments. Opinions were strong but divergent. Consumer focus groups were held to better understand how consumers interpret label claims. The draft guidance document is available on the FDA Web site at www.fda.gov.

The three nutritionally enhanced foods mentioned above—Golden Rice, lycopene-enhanced tomatoes, and highly monounsaturated soybean oil—would not meet the substantial equivalence criteria precisely because their nutritive value is enhanced. They would be subject to mandatory labeling.

A bill currently before Congress—HR 2916, known as the Genetically Engineered Food Right to Know Act—would require the labeling of all foods containing genetically engineered materials. The bill would also allow for nongenetically engineered foods to carry a voluntary label indicating that the product does not contain genetically engineered materials. Proponents of the bill argue that consumers have a right to know whether or not a food was genetically engineered.

The following message is currently being printed on the label of Hunt’s spaghetti sauce products: “According to the American Dietetic Association, lycopene as well as vitamins A and C are naturally found in tomatoes. For more information on the health benefits of tomatoes, go to www.eatright.org.”20 As there are currently no lycopene-enhanced tomatoes available to food processors, this label statement is correct. But if such tomatoes are eventually used, would the amount of lycopene in lycopene-enhanced tomatoes be considered the amount that is “naturally found in tomatoes?”

Consumers clearly need more information, and dietitians are in a unique position to provide it. One excellent source of information is the Pew Initiative on Food and Biotechnology, a nonprofit, nonpartisan research project whose mission is to inform the public and public policy makers about biotechnology issues (http://pewagbiotech.org).

The debate over genetically engineered plants and animals and the GM foods that are produced is not likely to subside soon. The magnitude of the issues and their far-reaching consequences will present us with food for consumption as well as food for thought.

— Marie Dunford, PhD, RD, is a nutrition writer and editor who lives in a small agricultural community in California. She has written a course on Technology, Food & Nutrition for Nutrition Dimension and is the author of Nutrition Logic: Food First, Supplements Second.

References for this article are available upon request by e-mailing TDeditor@gvpub.com.

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