In the last few decades, the revolutionary advances made in genetic engineering techniques—enabling scientists to insert DNA sequences into organisms—have opened new worlds of scientific research and medicine. In daily life, the embodiment of this technology is the genetic engineering of plants to create edible genetically modified (GM) food. Plant scientists are striving to genetically engineer plants to increase either the nutritional value or the yield. One can imagine ways in which this technology offers great possibilities to improve agriculture; however, there are also many concerns. There is a debate about whether or not GM food will fulfill its potential to advance modern agriculture and if the technology could do more harm than good to consumers, agriculture, or the environment.

The ‘Green Revolution’

After WWII, agriculture underwent what is known as the ‘Green Revolution’ in which substantial increases in food yield were gained from nitrogen-based fertilizers, increasing mechanization of large-scale farming, improvements in irrigation, and the breeding of new crop varieties. These changes provided increased food production needed for the rising human population. One visionary figure in the ‘Green Revolution’ was the American scientist Norman Borlaug who, supported by the Rockefeller Foundation, launched a program to improve agricultural yields in Mexico. In the 1940s when his work began, Mexico had to import half its wheat. By 1956, aided by the ‘Green Revolution’ strategy, Mexico was self-sufficient in wheat production and then began to export the crop. Borlaug’s work was a striking example of the transformative power of science. He had taken a scientific approach to the problem, rigorously analyzing and testing possible solutions and training local scientists in the areas where he worked. In 1970 his work was honored with a Nobel Peace Prize. A key question in agriculture today is whether the ‘Genetic Revolution’ will usher in the same striking agricultural enhancements that the ‘Green Revolution’ did.

Current GM farming

In 2004 an estimated 200 million acres were devoted to GM crops (about 2% of the total global agricultural land), grown by 8 million farmers in 17 nations. The five nations with the largest GM acreage were, in order, the USA (59% of the total global GM acreage), Argentina, Canada, Brazil, and China¹. In the USA almost all of the GM crops have been engineered to increase crop yield, either the crop has been engineered to have herbicide resistance or to prevent insect attack by producing an insect toxin from the bacterium Bacillus thuringiensis ( Bt ). In 2005 in the USA GM crops accounted for 90% of soybean grown, over 50% of the cotton crop, and 30% of the corn crop², with the GM percentage share of these crops rising steadily since their introduction in the mid 1990s.

Testing and Regulation

GM crop plants in the USA are regulated by three governmental agencies: the Food and Drug Administration (FDA) has jurisdiction over all food and feed uses of GM foods from plants, the United States Department of Agriculture (USDA) oversees the planting of genetically engineered crops, and the Environmental Protection Agency (EPA) which monitors planting and consumption of pesticides, such as Bt, engineered into plants. In 1986, these three agencies formed the Coordinated Network for Regulation of Biotechnology to evaluate products developed using modern biotechnology (http://usbiotechreg.nbii.gov/). This framework emphasizes that risk assessment will be based on the product itself, not the process by which the product was developed. In contrast the European system focuses on the process of generating the food.

Usually, the first agency to evaluate the safety of new transgenic crops is the USDA. First, registrants must obtain a trial permit to test the crop on controlled fields to see if the plants have an impact on the ecosystem. The researcher then petitions for non-regulated status, which allows relief from regulatory restrictions from the USDA, except in the unusual case of proven harm. If the plant produces a pesticide, EPA approval is needed for a field trial for ecological assessment.

Determining food safety, however, is not as straightforward. The concept of ‘substantial equivalence’ governs the regulation of food safety of GM foods. It was deemed sufficient to assess the safety of a new GM food relative to the non-GM original counterpart.

The company’s scientists test the GM crop for allergens, toxins, and anti-nutrients (compounds that inhibit the absorption of nutrients) and this data is submitted to the FDA. If the levels are ‘substantially equivalent’ to the conventional plant, the GM plant is approved for commercial sale and consumption. The FDA grants Generally Recognized As Safe (GRAS) status to GM foods, which means that these foods do not undergo additional tests or analysis with the FDA, unless there is a claim of a nutritional or health benefit. The guidelines for the conduct of food safety assessment of foods derived from GM plants are available online³. The rationale for this approach is that because whole foods are complex mixtures of compounds, animal studies cannot be readily applied for toxicological assessment because if any toxicity were found, it would be difficult to pinpoint what part of the food caused the toxicity. A report by the USA General Accounting Office contains recommendations for enhancing the effectiveness of the FDA’s evaluation of GM foods, including randomly verifying submitted test data, and increasing the transparency of the safety evaluations⁴. This would also improve the public’s confidence in the safety of GM foods. It is apparently still deemed unfeasible by scientists and regulatory officials to monitor long-term health risks of GM foods, as there is no scientific evidence of such possible harm and such studies would be technically challenging.

Labeling

The Grocery Manufacturers of America estimates that between 70 and 75 percent of all processed foods available in grocery stores in the USA may contain ingredients from genetically engineered plants⁵. Labeling is not required in the USA for GM food (unless it introduces an allergen, or is claimed to alter a food’s nutritional content). Unlike the situation in the USA and Canada, there is a mandatory labeling system for GM food in Europe and the rest of the western world. There have been attempts to introduce GM labeling legislation in the USA, but no federal or state legislation on this issue has been passed to date. In 2001 the FDA issued guidelines for voluntary labeling of foods containing (or not containing) GM food. There is a range of issues to consider in the implementation of a labeling system such as the ability to separate biotech and non-biotech products during processing or shipment, and how to classify a non-genetically engineered product from a GM organism, for example soy oil extracted from a plant that was engineered with herbicide resistance.

Public Perceptions and Confidence

Surveys have generally shown that US consumers have greater confidence in GM than their European counterparts, partly due to more negative press coverage in Europe and higher confidence in government regulatory bodies in the USA⁶. In Europe consumer confidence in the food supply was badly shaken in the 1990s over mad cow disease and its possible linkage to human Creuzfeldt-Jakob Disease⁶. The 2002 Eurobarometer study, a survey of 16,500 respondents from 15 EU member states, showed that a majority of Europeans do not support GM foods⁷. This study also revealed that public understanding of the underlying science is very poor. Those surveyed were given statements to which they had to respond true/false/don’t know. In response to, “Ordinary tomatoes do not contain genes, while genetically modified tomatoes do,” only 36% of respondents knew that this statement was false, 35% thought it was true, and 29% didn’t know whether it was true or false. The statement, “By eating a genetically modified fruit, a person’s genes could also become modified,” was thought to be true by 20% of respondents, false by 49% of respondents, and 31% didn’t know.

Environmental Concerns about GM crops

A major environmental concern about the introduction of GM crops is breeding between GM crops and non-GM plants. In the case of pesticide-resistant GM plants, this could lead to generation of ‘superweeds.’ The use of antibiotic-resistance markers in the genetic selection process to create GM plants created worries about horizontal transfer of these genes, however non-antibiotic-dependent markers have now been developed.

Loss of genetic diversity may occur if wild species become crossbred with their GM relatives. Genetic diversity is needed to recover from crop failure. Current large-scale farming practices—the monoculture of genetically uniform crops—is very vulnerable to a catastrophic failure if the right pest attacks, and in the 1970s a corn blight destroyed a substantial fraction of the corn crop in the USA. After this event, farmers had to turn to landraces, crops cultivated on a much smaller scale with higher genetic variability, to replenish the commercial stocks. Landraces though may be at risk. In 2001, a study revealed that although growing of GM maize was illegal in Mexico, the genetic markers of GM were found in crops grown by traditional farmers in rural Mexico⁸. The patenting of GM crops means that cross-contamination may have serious financial implications for farmers. In Canada in 2001, a farmer named Percy Schmeiser was sued successfully by the company Monsanto when some of his canola crop became herbicide resistant because of contamination by GM crops. Even though he wasn’t using the herbicide on his crops, the judge ruled that he was breaching Monsanto’s intellectual property rights. One scrapped industry solution to the problem of cross-contamination was the creation of so-called ‘Terminator technology’ to produce sterile GM crops. Environmentalists evoked cataclysmic imagery of these ‘Terminator’ genes being unleashed into the environment as a genetic equivalent of the Silent Spring of pesticide use in the 1960s. Cross-contamination is also a concern in the area of ‘biopharming’ in which pharmaceutical products are made in a GM crop. ‘Biopharming’ is still in its infancy, but in 2002 the USDA found corn containing an undisclosed pharmaceutical drug contaminating two cornfields in Iowa and Nebraska⁹.

The environmental impact of GM Bt corn came under intense scrutiny in 1999 when scientific research showed that pollen from Bt corn caused the death or stunted growth of larvae of Monarch butterflies¹⁰. Monarch larvae feed on milkweed plants, which are often found at the edge of cornfields. However, the EPA had never tested or considered the impact of airborne Bt pollen reaching milkweed plants. How accurately the levels of Bt pollen used in the laboratory mimicked the real situation outdoors was debated, but one thing was clear, the GM testing and regulation had fallen short. To settle the matter, a two-year investigation was carried out by academic and government scientists, with funding provided by industry and the USDA. According to Dr. Margaret Mellon of the Union of Concerned Scientists, “This was a model way to go about getting information on whether or not a risk exists. It brought together scientists, environmental and government folks together with industry…This was a really important process which should be followed routinely by the government as it makes decisions about GM products—and it’s not⁹.” The results of the study concluded that the risk to Monarch butterflies from Bt corn was negligible¹¹.

A recent study suggests that although GM crops have grown in popularity, they may not be efficiently reducing pesticide use. A 2004 report analyzed data from the USDA’s National Agricultural Statistics Center¹². The study concluded that Bt corn has reduced pesticide use on this crop. However there appeared to be increased pesticide use (estimated at 15%) on the herbicide resistant crop. This increased pesticide use was attributed to the increased appearance of herbicide resistant weeds as well as major herbicide price decreases.

Golden Rice

One prominent example of GM technology designed to enhance the nutritional content of food is Golden Rice, which was created to help alleviate Vitamin A deficiency problems. Rice, Asia’s staple crop, is not a source of Vitamin A, which is needed for healthy eyesight and immune system functioning. The WHO estimates that Vitamin A deficiency results in the death of a million children under five and the blindness of up to half a million children annually. In 2000, academic researchers in collaboration with AstraZeneca announced the creation of Golden Rice designed to produce β-carotene that can be converted to Vitamin A¹³. At the time this advance was hyped by industry, and Time magazine ran a cover story with the headline, “This rice could save a million children from going blind.” Environmentalists in particular greeted the new seed with skepticism. The Indian scientist Vandana Shiva cautioned that a normal daily intake of Golden Rice would not be sufficient to provide the daily requirement of Vitamin A and that there were other non-GM options available to tackle the problem, such as promotion of diet diversification. She also warned against industrial control of the technology, describing Golden Rice as, “a very effective strategy for corporate takeover of rice production, using the public sector as a Trojan horse.” Golden Rice has not yet been released on the market as a crop harvested for human consumption. In 2005, Syngenta developed a new Golden Rice strain with twenty times higher β-carotene production¹⁴.

Global Hunger

In 2005, of the world’s population of 6.5 billion people, 1 billion people live in extreme poverty defined as living on less than one dollar a day. 840 million people worldwide are malnourished (unable to eat enough to fulfill their basic energy requirements) and 6 million children under age 5 die annually as a result of malnutrition. In 1998 there were 5 billion tons of food produced globally and evenly distributed this would have been enough food for the world’s population, with enough to spare for an extra 900 million people¹⁵. Clearly some of the alleviation of global hunger will require political willpower, however scientists may be able to make a contribution through new technologies. Although a lot of the new technology is in the hands of just a few major corporations, efforts are also being made so these techniques can reach the developing world. PIPRA (www.pipra.org) is an initiative by universities, foundations, and non-profit research institutions to make agricultural technologies more easily available to provide subsistence crops for humanitarian purposes in the developing world. At present the area of greatest global food concern is sub-Saharan Africa, which has been devastated by AIDS and wars, and lacks much basic infrastructure. In this region in 2002 there were 34 million more people with insufficient food than there had been in 1990¹⁶, yet research to improve agriculture there is virtually nonexistent. In his Nobel Prize acceptance speech Norman Borlaug noted, “Vast sums are now being spent in all countries, developed and developing, on armaments and new nuclear and other lethal weapons, while pitifully small sums are being spent on agricultural research and education designed to sustain and humanize life rather than to degrade and destroy it.”

References:

¹ http://www.isaaa.org

² http://ers.usda.gov/publications/tb1903/tb1903.pdf

³ http://www.codexalimentarius.net/download/standards/10021/CXG_045e.pdf

⁴ http://www.gao.gov/new.items/d02566.pdf

⁵ http://www.fda.gov/fdac/features/2003/603_food.html

⁶ Science 1999 285:384-387

⁷ http://europa.eu.int/comm/public_opinion/archives/ebs/ebs_177_en.pdf

⁸ Nature 2001 414:541-543

⁹ Food Inc. Peter Pringle (2003) Simon and Schuster

¹⁰ Nature 1999 399:214

¹¹ Proceedings of the National Academy of Sciences 2001 98:11937-11942

¹² http://www.biotech-info.net/technicalpaper7.html

¹³ Science 2000 287:303-305

¹⁴ Nature Biotechnology 2005 23:482-487

¹⁵ http://nobelprize.org/peace/articles/borlaug/index.html

¹⁶ http://unstats.un.org/unsd/mi/mi_dev_report.htm