Are genetically modified foods and crops dangerous to human health and to the environment

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Are genetically modified foods and crops dangerous to human health and to the environment?

Viewpoint: Yes, genetically modified foods and crops, which result from techniques that may have profound, unanticipated, and dangerous consequences, are dangerous to human health and the environment.

Viewpoint: No, genetically modified foods are not dangerous; they are essential for the world's future.

In the 1970s, scientists learned how to cut and splice DNA to form recombinant DNA molecules and began developing techniques that made it possible to isolate, clone, and transfer genes from one organism to another. Scientists hoped that the new techniques of molecular biology, often referred to as genetic engineering, would be used to treat genetic diseases. But it was soon clear that genetic engineering could also be used to manipulate the genetic materials of plants, animals, and microorganisms for commercial purposes.

Responding to widespread fears about the safety of recombinant DNA technology and genetic engineering, the City Council of Cambridge, Massachusetts, proposed a ban on the use of gene splicing experiments in area laboratories. Other cities and states debated similar bans. However, the development of guidelines for recombinant DNA research and the successful use of the technique to produce valuable drugs, like human insulin and erythropoietin, diminished public anxieties. Recombinant DNA techniques also led to the development of transgenic organisms and genetically modified (GM) crops.

By the 1990s, GM crops were being field-tested or commercialized in the United States, Canada, Argentina, and Australia. Critics of the new technologies called the products of GM crops "Frankenfoods" and insisted that GM crops were dangerous to human health and the environment. The Cartagena Protocol on Biosafety, sponsored by the United Nations Convention of Biological Diversity, was adopted in 2000. The goal of the Protocol was to regulate the trade and sale of genetically modified organisms. However, in Europe and the United States concerns about the safety of genetically modified foods led to protests, boycotts, and demands for bans on GM foods.

Genetic modification of plants and animals usually involves the addition of a gene that provides a desirable trait not ordinarily present in the target variety. Those who support the use of genetically modified plants, animals, and foods believe that GM products will become essential components of our future food supply. Particularly in areas of the world threatened by malnutrition, famine, and starvation, GM crops seem to promise benefits in terms of costs, safety, availability, and nutritional value of staple foods. Predicting a global population of 7 billion by 2013, demographers warn that agricultural biotechnology and productivity will become increasingly critical in the not-too-distant future. Genetically modified plants and animals could be used as a source of drugs, vaccines, hormones, and other valuable substances. The addition of appropriate genes may also help accelerate the growth of plants, trees, and animals, or make it possible for them to grow and flourish in harsh climates.

Based on studies of GM foods and comparisons with conventional food sources, most scientists consider GM products to be safe for the environment and for human consumption. Indeed, many common food sources, such as potatoes and manioc, contain chemicals that can be toxic or dangerous to some or all consumers. Conventional foods, such as peanuts, are extremely dangerous to people with allergies, while others contain chemicals that may cause cancer or birth defects. Part of a plant may be toxic, such as rhubarb leaves, whereas other parts are safe to eat. Moreover, supporters contend that GM crops are subjected to higher level of scrutiny than plant varieties developed by traditional breeding techniques.

Molecular biologists note that critics of GM foods seem to ignore the difference between genes and gene products. Therefore, opponents of GM foods claim that the product of an exotic gene will be present in every cell of the GM organism, so that consumers will be subjected to dangerous levels of both the exotic gene and the protein it encodes. Such arguments fail to take into account the fact that although every cell in the organism contains the same genes, not all parts of the organism contain the same gene products. For example, all cells contain the gene for hemoglobin, but this protein is only found in red blood cells.

Genetic engineering has been used to create plants that synthesize their own insecticides, plants that are resistant to herbicides, viral diseases, spoilage, and cold, and plants that are enriched with vita-mins or other nutrients. For example, a strain of rice known as "golden rice" was modified to contain higher levels of a vitamin A precursor. Although half of the world's population depends on rice as a staple food, rice is a poor source of many essential vitamins and micronutrients. The United Nations Children's Fund predicts that eliminating vitamin A deficiency could prevent one to two million deaths each year among children aged one to four years. Advocates hope that GM foods will be looked at positively in the light of "nutritional genomics" fighting malnutrition rather than the source of "Frankenfoods" designed to increase the profits of commercial enterprises. They note that research on golden rice was funded by grants from the Rockefeller Foundation, the Swiss Federal Institute of Technology, and the European Community Biotech Program.

Critics of genetic engineering believe that the potential economic advantages of GM plants, animals, and foods are encouraging the development of organisms and foods that may be dangerous to humans and to the environment. For many millennia, farmers have used classical selection and hybridization techniques to produce plants and animals with desirable characteristics, but they were unable to deliberately transfer genes from one species to another. Although scientists may hope to effect the very specific transfer of one highly desirable gene, critics argue that the impact of the exotic gene might have profound, unanticipated, and dangerous consequences. Indeed, although the genomes of many species have now been sequenced, much remains to be discovered about genetic regulation. The addition of exotic genes into widely used crops raises the possibility that GM foods could provoke allergic reactions in susceptible individuals. Another concern raised by critics is that once GM crops are common, pollen from these plants might be accidentally transferred to other plants, with unpredictable results.

At the very least, opponents of GM foods want to have such foods clearly labeled so that people will be able to choose whether or not they want to consume them. Survey of public attitudes towards biotechnology in the 1990s suggested that GM foods were much more controversial in Europe than in the United States. Although there was more press coverage of the issue in Europe, much of it more positive than press reports in the United States, about 30% of Europeans expressed opposition to GM foods.

The history of biotechnology regulation in Europe and the United States has taken different paths. In the United States, most of the major regulatory issues were settled by 1990. Generally, biotechnology products were regulated within existing laws and procedures. In Europe, however, regulators attempted, rather unsuccessfully, to establish new regulatory procedures to deal with biotechnology issues. This approach created more widespread public debate and uncertainty. Surveys indicated that Americans had higher levels of trust in their regulatory agencies than was the case in Europe.

The dream of mixing characteristics from different sources to produce the best offspring is very ancient, but the outcome of classical or modern genetic techniques is not always predictable. According to playwright George Bernard Shaw, a beautiful actress once proposed that they should have children together. She was sure that the children would have her beauty and his brains. Shaw, however, warned her that the children might suffer by inheriting her brains and his face. Scientific literacy remains a problem, as demonstrated by the response to a survey on attitudes towards biotechnology carried out in 1997 in the United States and Great Britain. Many of the respondents believed that GM tomatoes contained genes, but natural tomatoes did not. Since the introduction of recombinant DNA technology in the 1970s, it has been very difficult to conduct an informed debate about biotechnology issues, but it is difficult to imagine a scientific debate more polarizing than the one being waged over the safety of GM foods.

—LOIS N. MAGNER

Viewpoint: Yes, genetically modified foods and crops, which result from techniques that may have profound, unanticipated, and dangerous consequences, are dangerous to human health and the environment.

Proponents of genetically modified (GM) organisms, particularly crops and foodstuffs, maintain that the genetic modifications are intended to make the crops more hardy and healthful, and to make more food available to more people in need. Though such altruism may, in fact, apply in some cases, it is far closer to the truth to say that corporate profit is the real impetus behind the GM movement. Yet there are very real dangers inherent in GM crops and foods. These dangers, described below, threaten human and animal health and the health of ecosystems. As you will see, proliferation of GM organisms poses a dire threat to the future of agriculture and, perhaps, to the survival of natural ecosystems.

What Is Genetic Modification?

Classical Agricultural Manipulation.

For the last 10,000 years or so—since the Agricultural Revolution—humans have been growing and raising their own food. From the very beginning, farmers have tried to improve their crops and livestock by selective breeding. For example, farmers would save seeds from those tomato plants that bore the most and the sweetest fruit. They would plant only these seeds and, through ongoing selection of seeds from plants with the most desirable traits, they would change and improve the yield, the hardiness, and the quality of the crops they grew. This kind of classical manipulation of agricultural products has been going on for centuries.

Cross-breeding is another kind of classical manipulation of crops. A farmer might notice that one tomato plant yielded many fruits and that a different tomato plant was highly tolerant of cold. The farmer might cross-breed these two plants—transferring the pollen of one to the pistil of the other—to yield a tomato plant that both yielded many fruits and that was tolerant of cold. This kind of crop manipulation involves the mingling of genes from two closely related plants—all the genes involved in this cross come from tomatoes.

What farmers could never do was cross-breed or transfer genes from two totally unrelated organisms. That's the realm of genetic modification.

Biotechnology Defined.

Genetic engineering—biotechnology—is the process in which a gene from one organism is inserted into the genome of a completely dissimilar and unrelated organism. The inserted gene causes all or some of the cells of the host organism to produce a particular substance (a protein) or to manifest a particular trait.

For example, in classical selective breeding, a farmer trying to breed a variety of tomato that is tolerant of extreme frost has rather limited options. That's because there is a limit to the degree of cold tolerance inherent in the genes of any tomato variety. In the genetically modified world, however, a scientist can insert into the tomato plant a gene from a bottom-dwelling fish that codes for the production of anti-freeze. Thus, the tomato might conceivably grow in the Arctic because the fish gene causes the plant to produce a kind of anti-freeze.

Proponents of genetic engineering claim that it permits them to transcend the natural genetic limits of a particular class of organisms; for example, the tomato plant's limited genetic ability to tolerate freezing temperatures. Increasingly, however, scientists and the public are questioning the wisdom of such manipulations.

Genetic engineering's ability to transfer genetic material—not within or even between species, but across entire phyla or kingdoms; in fact, from anywhere in nature—is extremely worrisome. Many scientists believe that this compromises the essential identity and integrity of individual species. Further, because genetic modification is concentrated among crops, which are grown openly on the land, there is a grave risk that these GM organisms cannot be contained, but will spread their altered and, literally unnatural, genes throughout natural ecosystems—with unforeseen, but likely dire effects.

There are dangerous misconceptions and numerous risks inherent in genetic engineering. These include: (1) misunderstanding genetic interactions; (2) risks to human health; (3) gene escape; and (4) testing, regulation, and labeling. Each is discussed below.

Genetic Misconceptions

The One-to-One Myth.

Genetic engineers operate on the assumption that genes and traits have a direct, one-to-one relationship. They genetically manipulate organisms based on the idea that single genes are distinct, determinate, and stable, and that they function in isolation from other genes. For example, they believe that a fish gene for cold tolerance codes only for that one trait, and if it is inserted into another organism it will confer on it only that one trait. This idea is considered extremely simplistic and patently false.

Genetic material works in conjunction with other genetic material. A gene inserted into DNA is affected by the other genes that make up the DNA: it interacts with these other genes, and it is influenced by these genes and the proteins they produce. The organism itself affects all its genes, and, as the environment affects the organism, so too does the environment affect the genes. Thus, simply inserting a gene for a trait does not mean that that trait will be expressed purely or in a way that the scientists intended. And it certainly does not mean that that gene will reside in the organism's DNA without affecting the genes surrounding it. There are no data to indicate the nature of the changes the inserted gene has on the organism's natural genetic makeup. Yet scientists know for a fact that genes interact with and affect each other. And everyone knows that genes mutate from time to time. As yet, we have no way of knowing how an alien, inserted gene will affect an organism's DNA over time. If the inserted gene is later shown to have disastrous effects on the organism, there is no way to undo the genetic damage.

The "Junk" Myth.

Genetic engineering also operates under the outdated assumption that it is safe to insert alien genes into the 95% of genetic material that was once called "junk genes." Scientists noted that only about 5% of an organism's genes seem to actively code for a known protein and purpose. That's why the remainder of the genes, whose purpose they could not figure out, were called "junk."

Recent research has shown that these "junk" genes are anything but. The research strongly indicates that "junk" genes are very likely a vital "backup" for the more active genes. Further, in the 1990s, studies show that interference with these random genes can have dire effects. If these genes are altered, they tend to mutate. If a gene (whether alien or from another region of the organism's own DNA) is inserted into a region of random genes, the rate of genetic mutation increases sharply. In some experiments, the genetic mutations were associated with disease.

Health Effects

There are many potential, or at least unresearched, health risks involved in GM crops and foods.

Eating Alien Gene Products.

There may be a risk attendant upon consuming foods that contain genes from what are generally non-food organisms.

There is a grave risk involved when genes known to be harmful to living things are inserted into consumables. This is the case for GM potatoes and other crops (particularly soy and corn). These GM crops have had inserted into their DNA a gene that produces a naturally occurring pesticide. The pesticide, Bt (Bacillus thuringiensis), is toxic to certain insect pests. When the gene is inserted into the crop seed, every cell of the growing plant contains this gene. When people eat these GM foods, they ingest the pesticide.

The GM plant is naturally resistant to the insect pests that would otherwise devour it, so the genetic modification helps farmers get a good crop and allows crops to be grown with fewer pesticide applications. Yet there is little or no research on the human health effects of a lifetime of eating pesticide-laden foods. A pesticide is a chemical that is toxic to at least some living things. What is the effect of a lifetime of ingesting GM foods?

Allergies.

In the 1980s, biotech scientists genetically engineered a new strain of celery, which grew better and lasted longer in the supermarket produce section. Alas, it had to be withdrawn after people who handled it or ate it broke out in a severe rash. A potato produced in the 1990s, genetically modified to enhance its nutritional value—a worthy endeavor—ended up making consumers violently ill. It turns out that the genetic modification that boosted the potato's nutrients also caused the plant to produce toxic levels of glycoalkaloids. The genetic engineers had no idea that the simple insertion of a single gene would have this unforeseen and dangerous outcome.

Also in the 1990s, genes from Brazil nuts were inserted into soy beans to enhance their protein content—again, a worthwhile goal. But the beans were not labeled to show they were genetically engineered. Trusting consumers who ate the extra-nutritious beans had no idea that they contained the nutty genes. People allergic to Brazil nuts fell ill, some seriously. Tests done on non-human animals did not reveal this side effect.

In 1998, researchers tested the health effects of a crop plant into which a virus gene had been inserted. (The virus gene gave the plant resistance to a bacterial plant disease.) Mice were fed the GM plant. The scientists found that in the process of digestion, some of the virus genes escaped into the animals' bloodstream. The more GM plants the mice ate, the greater the blood level of the virus. This research shows that alien genes in GM foods can escape into the body. What scientists don't yet know is the health effects caused by alien virus genes that remain in and circulate through the body.

Finally, there are the health effects that arise directly from the corporate profit motive. For example, Monsanto is a world leader in the creation and production of genetically modified crop seeds. The company also manufactures agricultural chemicals; Roundup®, for example, is an herbicide made by Monsanto. Its GM division has developed "Roundup-ready" plant seeds, which yield crops that are impervious to the plant-killing effects of Roundup®. Thus, a farmer can douse his fields with far more herbicide than he would otherwise, because he knows that his cash crop will be unaffected. Yet when that cash crop is harvested and sold as food, it contains far more toxic herbicide than it would have had if it been naturally herbicide sensitive. The plant food is sold to consumers as being identical to and as safe as any non-GM food, yet it contains far greater quantities of herbicides, which are known toxins. Again, the question must be raised about the health effects of lifelong consumption of herbicide-laden foods.

Gene Escape

At the heart of genetic engineering lies an unavoidable contradiction. On one hand, genetic engineers operate under the assumption that genes are universally transferable, even across entire kingdoms and phyla of unrelated organisms. On the other hand, they reassure a worried public that once alien genes are transferred into an organism they cannot and will not spread further—into non-target, wild organisms, for instance.

Research has shown that alien genes inserted into an organism—transgenes—have escaped and become incorporated into wild organisms. The effects of gene escape are unknown, but most scientists believe they will likely be catastrophic.

In the late 1990s, British researchers found that transgenes from GM rapeseed plants in a 123-acre experimental field escaped and were incorporated into the genetic material of weeds growing more than one mile away. Further, when the crop was harvested, some seeds naturally fell on the ground and were eaten by birds. Evidence was found that the birds had transferred the transgenes to plants many miles away.

In another study, researchers discovered that plants genetically engineered to withstand the effects of heavy applications of herbicides did well in an herbicide-doused field. Yet in a "natural environment" in which herbicide was not used, the plants did very poorly. The scientists concluded that if this transgene escaped into the wild (where, of course, herbicide is not used) and was incorporated into wild plants, these wild plants would also do poorly (due to lack of herbicide in the natural environment). With transgene-infected wild plants growing poorly, wildlife and the entire ecosystem will suffer and may even face collapse.

A research report published in the September 1999 issue of Nature revealed that, contrary to the assertions of the biotech industry, genetic material from GM plants was far more likely to escape into the wild than were genes from non-GM plants. The scientists state that an organism's natural genes are more securely "attached" to the chromosomes because they have evolved in response to other genes and the environment over millions of years. The research underlines the inevitability that alien transgenes will escape and become incorporated into the genetic material of wild plant species and varieties. Any mutations or negative effects the transgenes have on wild plants will be irreversible. Once genes escape and spread through the wild, there is no way to recall or stop them. Since we don't know what effects transgenes will have on wild plants, it is surely wise and prudent to study their potential effects thoroughly before permitting their widespread use.

The "Super" Syndrome

Some scientists insist that the inevitable escape of transgenes into the wild will have disastrous effects not only on ecosystems, but on agriculture as well. Consider—

Super-weeds.

Some GM crop plants are genetically engineered to resist the effects of herbicides. What happens when, inevitably, the genes for herbicide tolerance are transferred from crops to pesky weed species? Once weeds become resistant to herbicides, there'll be no stopping them. In a way, the herbicide-resistant genes inserted into crops contain the "seeds" of their own destruction. Sooner or later, their herbicide-resistant genes will escape and be incorporated into the very weeds the herbicides are intended to kill. Then what?

Super-bugs.

Among the most popular and widespread applications of genetic engineering is the transfer of genes to plants that confer resistance to pests and plant diseases. Inevitably, these genes escape to wild plants, which incorporate the gene and themselves become resistant to insect pests and plant diseases. As is by now well known, insect pests and the bacteria and viruses that cause disease reproduce so rapidly that sooner or later—usually sooner—they become immune, or resistant, to whatever is trying to do them in. It is therefore only a matter of time before the GM crops succumb to new, improved Super-pests or Super-diseases—insects, bacteria, and viruses that have developed resistance—immunity—to the genetic modification. What do we do then to combat infestation and disease? What happens when these Super-bugs descend on the natural environment?

(It's interesting to note that in the entire history of humans' fight against crop pests, and despite an enormous arsenal of increasingly lethal chemical pesticides, not one insect pest species has gone extinct. They just adapt a resistance to every chemical thrown at them!)

Testing, Regulation, and Labeling

Scientists and a large segment of the public are legitimately worried about the widespread use of GM crops and foods. The general public may be less aware of the ecosystem-wide ramifications of transgene escape, but people are increasingly concerned about the human health effects of GM foods. For this reason, they are asking that GM foods and products that contain GM foods be labeled as such.

In the mid-1990s, senior scientists with the U.S. Department of Agriculture's (USDA) biotech division reported to agency heads that GM foods are so different from non-GM foods that they pose a serious health risk. The senior biotech scientists recommended that the USDA establish a protocol for testing this novel type of food. The scientists criticized the biotech industry's own safety data, which were accepted without question by the USDA, as "critically flawed" and "grossly inadequate." However, the USDA ignored these recommendations, publicly insisting that GM foods are identical to non-GM foods and therefore need no special safety testing or labeling. Memos that subsequently came to light (via lawsuit) showed that the federal government had directed the USDA to "foster" promotion and acceptance of GM foods. Thus, the USDA ignored the recommendations of its own senior scientists and compromised the health of the American people.

To date in the United States (unlike Europe), the reasonable request for product labeling has been either ignored or simply shot down. Despite the very real dangers of allergic reactions to foods containing genes from known allergens—not to mention the risks inherent in pesticide-laden foods—neither corporations nor the government agencies charged with assuring us a safe food supply will agree to label GM foods. In what is widely regarded as inaction in support of corporate profit, the government refuses to respect its citizens' right to make an informed choice. (A wonderfully told, and very telling, tale of the shenanigans that surround GM foods and the U.S. agencies that, supposedly, regulate their safety is Michael Pollan's article "Playing God in the Garden.")

Conclusion

Genetically modified foods and crops pose unforeseen and potentially catastrophic threats to wild plants and to ecosystems because of the inevitability of transgene escape and the evolution of resistant weeds, pests, and disease organisms. Misconceptions about how genes work within organisms pose the additional threat of mutations, which may threaten human health. Human health is threatened more directly by GM plant foods that contain known toxins. In sum, genetic manipulation of organisms for profit without adequate study of the consequences for human life or the environment is a very dangerous and potentially catastrophic undertaking. As Pollan described it: "Biological pollution will be the environmental nightmare of the twenty-first century … [it] is not like chemical pollution … that eventually disperses … [it is] more like a disease."

—NATALIE GOLDSTEIN

Viewpoint: No, genetically modified foods are not dangerous; they are essential for the world's future.

Genetically modified (GM) plants and animals have only been available for a few years, but already they are becoming key elements of the food supply. The reason for the rapid acceptance of genetically modified foods by farmers and food producers is that they provide several advantages, including cost, safety, and availability in areas of the world where people are starving. These advantages will only become more and more apparent as their presence in the food supply becomes more dominant. Such dominance is not a matter of "if," but of "when." A survey of the different types of GM plants and animals being developed indicates why this is the case, and also indicates why prospects are good that these organisms are not only useful but safe to both humans and the environment.

It should be noted at the start that "safe" is always a relative term. No food, no matter how "natural" it may be, is without risks. Eating too much of anything can cause problems—a man who for months ate tomatoes at almost every meal ended up turning orange from the pigments in this vegetable. A number of natural foods contain toxic substances, though usually in very small quantities. For example, carrots and potatoes both carry toxins, but these aren't a problem in the quantities they are usually eaten. Such plants have never been subjected to the scrutiny that GM foods have received. In the United States, the Environmental Protection Agency (EPA) demands information on the safety of GM crops—both to humans and to the environment—before these crops are planted in open fields. This is a greater level of review than is given to plants that are created by more traditional breeding programs, such as crossing different strains of a plant to produce seeds carrying novel sets of characteristics. This type of breeding has been going on for centuries, with little concern about the safety of the plants created in this way. Yet there can be problems with this approach. For example, a carrot strain produced by such the traditional breeding program was found to be high in toxins, and the same was true of a new potato strain.

Protecting Against Pests

One approach to the genetic engineering of plants is to insert a gene into a plant that makes the plant more resistant to pest damage. Many plants produce chemicals that taste unpleasant or are toxic to insects or slow insects' growth. These genes could be transferred to crop species that don't ordinarily possess them. Farmers could then grow plants that carry their own insecticides with them. This can reduce the spraying of insecticides that are sometimes toxic to humans as well as to other insects. In China alone, 400-500 cotton farmers are killed each year in accidents involving pesticides. Also, using such GM plants could make growing plants cheaper, since farmers wouldn't have to buy as much insecticide, and there would be less damage to non-target insects.

These benefits are more than just speculation or wishful thinking; there is solid evidence for each of them, and it comes from one of the earliest efforts to genetically engineer crop plants. A bacterium called Bacillus thuringiensis makes a substance that kills many common insect pests. Lures containing this substance have been used for years in gardens to keep down insect populations. Biologists took the gene for this chemical and inserted it into corn cells. The resulting corn plants, called Bt corn, make the substance and thus carry their own natural insecticide with them. Bt corn is now planted widely in the United States, as is Bt cotton. The fact that these plants have only been available for a few years, and that they have already been so widely accepted by farmers, indicates the value of this genetic modification. In addition, Bt corn has been found to be comparable to regular corn and doesn't cause any ill effects in humans who eat it.

Many of the problems that plague crop plants are not as obvious as insects. Invisible viruses can also destroy plants. Thanks to genetic engineering, biologists are now able to create plants that are resistant to viral diseases. African scientists have created a virus-resistant form of cassava, a yam-like plant that's a staple crop in many parts of Africa. Now they are working on a GM form of the sweet potato that is virus-resistant. These projects indicate that GM crops are not just for wealthy nations and may even prove to be more important in underdeveloped countries. Many of these nations have rapidly growing populations, some of whom are already living on subsistence diets, often low in important nutrients. And food crises are likely to worsen in the future as populations continue to increase. In such situations, GM crops may be the only way to provide sufficient, highly nutritious food to stave off malnutrition. Rather than being a threat to health, such foods may instead be essential to the well-being of large numbers of people. Still another way to improve yields is to prevent spoilage, a reason much food is lost before it gets to those who need it. Specific genes have been identified that slow ripening, so that vegetables and fruits with such genes can be transported to market and sold before they spoil.

Fighting Weeds

In addition to inserting genes that provide protection against pests and thus cut down on the use of pesticides, biologists have also found a way to make the use of herbicides more effective and less costly. Herbicides are chemicals that kill plants, and therefore can be employed as weed killers. The problem with their use in farming is that they also kill a lot of crop plants. However, biologists have identified genes that make plants resistant to herbicides, so the plants grow well even in their presence; these genes have now been transferred to many crop plants. This means that farmers can use a weed killer, and still have a good crop. This is economically important because overall, crop yields are reduced by 10-15% due to weeds, which compete with the crop plants for water, soil nutrients, and sunlight. Also, besides increased crop yields due to less competition from weeds, there is less need for tilling, so erosion, a constant problem for farmers, is reduced.

Health Benefits

In some cases, GM crops may provide real benefits to human health. A strain of rice has been developed that contains a gene to make beta-carotene, a nutrient the human body can convert into vitamin A. Vita-min A deficiencies are painfully common in many Third World countries, including countries where rice is the staple crop. This new type of rice, called golden rice because the beta-carotene gives grains a yellow color, could provide distinct health benefits. A vitamin A deficiency can cause birth defects, and in children and adults it can also cause skin problems, and perhaps more importantly, night blindness. Public health researchers calculate that curing vitamin A deficiencies could significantly reduce deaths due to night-time accidents in Third World countries. Many of these deaths can be linked to vision difficulties related to vitamin A deficiency. Another strain of GM rice, one that increases the iron content of the grain, could also be a boon to health, since iron deficiency is extremely common throughout the world, particularly among women and children. In the future, genes for many other nutrients could be added to a wide variety of crop plants, making many foods much more nutritious. This is particularly crucial in countries where most people are poor and the variety of foods available to them is limited.

GM food crops could also aid human health more indirectly. Plants can be genetically engineered to make molecules that could be used as drugs. For example, carrots have been engineered to produce a vaccine against hepatitis B. This vaccine can be produced in more traditional ways, but it is very expensive. A plant source for the vaccine would significantly decrease its cost. Research is also being done on developing GM plants that would produce a wide variety of vaccines, hormones, and other drugs that are currently expensive and difficult to make. Plants could produce these substances in large quantities, and purification of these substances from plant materials would be relatively easy and therefore economical. This would mean that many drugs now almost totally unavailable in Third World countries because of their cost would be obtainable by much larger numbers of people who desperately need them.

What should also be mentioned here are the benefits of genetically engineered animals as well as plants. Animals with added genes for growth will grow more quickly on less feed, making the health benefits of the high-quality protein in meat available to more people. The same argument can be made for adding genes that increase milk production in cows. Efforts are also underway to create GM animals that could serve as sources for vaccines and other drugs.

Protecting against Harsh Environments

Most of the world's available high-quality arable land, that is, land well-suited for growing plants, is already being used as farm land. With a rapidly growing world population that already includes over 1.5 billion people suffering from malnutrition, finding land on which to grow enough food to feed everyone well is going to become an increasingly difficult problem. Yet converting the world's rain forests to farmland is not considered an environmentally responsible answer to the problem. The poor soil of rain forests doesn't support agriculture for more than a few years, so farmers are forced to then destroy more rain forests, leading to spiraling environmental deterioration. Also, the loss of rain forests means the loss of many species of plants, animals, and microscopic organisms, thus depleting the Earth's biodiversity and worsening the present mass extinction many biologists consider the most severe in Earth's history. That's why the benefits of GM crops in increasing yields per acre by reducing crop loss due to weeds and pests are important, and that's why it's also important to extend agriculture into areas where the weather has been considered too harsh for large-scale agriculture in the past.

In such unpromising environments, GM crops can be invaluable. Plants can be engineered to be resistant to frost, thus extending the growing season in colder regions. Genes have also been identified that provide drought and heat resistance, making hot, dry lands more attractive for agriculture. Such areas may also benefit from GM plants with genes that allow them to grow in highly saline environments. This also means that salt water could be used for irrigation, something that has been impossible up to now because crop plants can't ordinarily tolerate high salinity.

It is undeniable that some GM organisms may cause environmental problems and may have some health consequences. But the monitoring of these plants by the Environmental Protection Agency means that problems are dealt with before the plants are used widely. Balanced against these difficulties, the dire consequences to the environment and human health of not using GM organisms are much greater. Malnutrition will become more widespread, more rain forests will be destroyed, and life-saving drugs will continue to be priced outside the means of a majority of the world's population. No innovation is without consequences, but in the case of GM foods, the benefits so outweigh the dangers that to hesitate is to court environmental and human disaster.

—MAURA C. FLANNERY

KEY TERMS

ARABLE LAND:

Terrain that is fit to be used as farm land, that can be easily cultivated.

DNA (DEOXYRIBONUCLEIC ACID):

A nucleic acid found primarily in the chromosomes that contains an organism's genetic information. DNA is the hereditary material of all organisms, which pass on their traits through their DNA.

GENETICALLY MODIFIED (GM) FOODS:

Foods that contain some plant or animal material that has been genetically altered. Usually, this means that a gene, a piece of DNA, has been added that provides the organism with a trait it would not ordinarily have.

HERBICIDE:

A chemical that can destroy plants or at least inhibit their growth; the targets of herbicides are usually weeds.

KINGDOM:

The highest level of organism classification. The kingdoms are Monera, Protists, Fungi, Plants, and Animals.

PESTICIDE:

A chemical that kills pests, most often insects.

PHYLA (SINGULAR, PHYLUM):

The major groups into which organisms are scientifically classified; a high-level category just below kingdom and above class.

TRANSGENE:

An alien gene inserted into the DNA of an organism (a trans [ferred] gene) through genetic engineering.

YOUR GM CUPBOARD

The following are just a few of the everyday foods that contain genetic modifications, primarily for the production of pesticides or for herbicide resistance.

Soy products.

Soy flour, soy oil, lecithin, vitamin E, tofu, veggie burgers and soy-based meat substitutes, soy sauce; products that contain soy or soy oil (comprising 60% of all processed foods): ice cream, yogurt, infant formula, sauces, margarine, baked goods, chocolates, candies, fried foods, pastas; also shampoo, bubble bath, cosmetics.

Corn products.

Corn flour, corn oil, corn starch, corn sweeteners, corn syrup; products that contain corn or corn derivative: vitamin C, tofu, chips, candy, ice cream, infant formula, salad dressing, tomato sauce, baked goods, baking powder, alcohol, vanilla, margarine, powdered sugar, enriched flour, pastas.

Canola products.

Canola oil; products containing canola oil: chips, peanut butter, crackers, cookies.

Potatoes.

Fresh potatoes, processed or restaurant potatoes and potato products: chips, vegetable pies, soups.

Tomatoes.

Fresh tomatoes; products containing tomatoes: sauces, purees, pizza, lasagna, and most Italian and Mexican foods.

Dairy products.

Cows are treated with hormones (BGH—bovine growth hormone and are fed GM feed, for example, corn products): cheeses, butter, sour cream, yogurt, ice cream, cream cheese, cottage cheese.

[source: Friends of the Earth: <www.foe.org/safefood/foodingredients.html>.]

—NatalieGoldstein

Science in Dispute