GM Foods—Bringing Rationality to the Debate
The war over genetically-modified foods continues to smolder, as evidenced by the recent class-action suit filed against Monsanto. While the agricultural-biotech companies and the organizations that represent them try to put out the fires, scientists at universities and research institutes, whose research largely laid the foundation for this technology, have largely stayed out of the fray.However, a group of researchers traveled to the WTO meetings in Seattle last month to present their views on the controversy. What follows are remarks presented by Martina McGloughlin, Director of the University of Davis Biotechnology Program to a conference entitled: "The public need for science, not fiction, on biotechnology."
Joining Martina McGloughlin on the conference panel were: Nina Fedoroff, director, Life Sciences Consortium and the Biotechnology Institute, Pennsylvania State University; Brian Larkins, professor, Department of Plant Sciences, University of Arizona; and Douglas Randall, professor, Department of Biochemistry, University of Missouri.
Biotechnology is one of the areas receiving a great deal of attention from environmental and consumer groups around the world. Most scientists working in the field are in total agreement with the stated mission of these groups that is we need to feed and clothe the world's people while minimizing the impact of agriculture on the environment. But the human population continues to grow, while arable land is a finite quantity. So unless we will accept starvation or placing parks and the Amazon Basin under the plow, there really is no alternative to applying biotechnology to agriculture. As noted by Dr. Norman Borlaug, Nobel Laureate, 1970 and Father of the green revolution, "Biotechnology is a new revolution providing feed, food and industrial products to support a global population increasing at the rate of 100 million per year."
Biotechnology should be looked upon not only as a solution to problems but also as a mechanism to improve the quality of life and the quality of the environment. Although GMOs are an extension of current technologies, today's biotechnology differs significantly from previous agricultural technologies. Using genetic engineering, scientists can enhance the nutritional content, vitamins, minerals, antioxidants, texture, color, flavor, growing season, yield, disease resistance, shelf-life and other properties of production crops. We are entering an era of Agricultural Biotechnology that will finally allow us to address longstanding nutritional deficiencies in the food supply, deficiencies that until now could only be partially addressed by fortification. The ability to manipulate plant nutritional content heralds an exciting new era and has the potential to directly benefit the farmer, consumer and overall health of the nation and the world. Scientists can use similar plant delivery systems to provide not just enhanced nutrition but also vaccines and therapeutics, which are especially important in developing countries. In addition to plants, engineered microbes and enzymes produced using recombinant DNA methods are used in many aspects of food production. The cheese and bread you eat and the detergent you use to clean your clothes all have used engineered enzymes since the early part of this decade.
By reducing dependency on chemicals and tillage through the development of natural fertilizers and of pest-resistant plants, biotechnology has the potential to conserve natural resources, prevent soil erosion and improve environmental quality. Strains of microorganisms could increase the efficiency, capacity and variety of waste treatment. Bioprocessing using engineered microbes offers new ways to use renewable resources for the production of materials and fuel reduce or dependence on fossil fuels. Biotechnology is, in fact, the low-risk alternative to current practices.
The vast majority of plant and agricultural scientists who are truly familiar with how crops have been developed through the years and the processes through which those foods have been evaluated, are amazed by the response of those that seemingly do not want the technology to be adopted. Some of these groups are established to promote protection of the environment, but are opposed to genetically modified crops that require less chemical insecticide, or reduce tillage and soil erosion. Other groups are truly concerned about the safety of the foods produced by new techniques that they do not understand, but have full confidence in foods produced by classical methods that they also do not understand.
The most cost-effective and environmentally sound general method for controlling pests and disease is the use of that totally organic substance DNA. This approach already has led to a reduction in the use of sprayed chemical insecticides. It has been estimated, based on recent scientific data, that growing genetically modified potatoes that carry genes for resistance to Colorado potato beetle and could eliminate the use of 1.35 million kilograms (or nearly 3 million pounds; 1,500 tons) of chemical pesticides. The savings of insecticides in cotton and corn are far larger. According to the U.S. National Agricultural Statistics Service, 2 million fewer pounds of insecticide were used in 1998 to control bollworm and budworm than were used in 1995, before "Bt" cotton was introduced. And the Bt gene -- introduced into the crop plant, not sprayed into the atmosphere -- is present in minute amounts and spares beneficial insects. Recent data also shows that crops genetically modified to be herbicide-tolerant have reduced the amount of chemicals used to control weeds because they permit the use of more environmentally friendly herbicides and reduce the need for pre-emergent spraying. If similar research efforts were undertaken on all of the major fruits and vegetables produced in this country, the reduction in the amount of pesticides used by the farmer that find their way into the soil, water, and air, and that can remain in some grocery produce, would be truly staggering.
In addition, thanks to biotechnology, an older, more environmentally friendly technology is enjoying a major resurgence. This cultivation technique is termed no-till agriculture. Unlike conventional tillage, which controls weed growth by plowing and cultivating, no-till agriculture uses quantities of selective herbicides to kill weeds. The resulting vegetation detritus protects seedlings when they are most vulnerable to the ravages of nature. Soil erosion is reduced. Beneficial insects in the debris are protected. And the till-less technique reduces equipment, fuel, and fertilizer needs and, significantly, the time required for tending crops. It also improves soil-aggregate formation, microbial activity in the soil, and water infiltration and storage, while enabling cultivation on slopes of up to 15 percent. This is definitely an attractive prospect for developing countries. Yet to be successful, no-till agriculture needs to be used in tandem with plants modified to be herbicide-tolerant and insect-resistant.
There is no evidence that recombinant DNA techniques or rDNA-modified organisms pose any unique or unforeseen environmental or health hazards. In fact, a National Research Council study found that "as the molecular methods are more specific, users of these methods will be more certain about the traits they introduce into plants." Greater certainty means greater precision and safety. The subtly altered products on our plates have been put through more thorough testing than any conventional food ever has been subjected to. Many scientists who worked in the past on crop improvement using much less precise methods of cross breeding, or mutation-induced breeding, or wide species crosses did not undergo the same type of scrutiny or inquiry. Ironically, many of our daily staples would be banned if subjected to today's rigorous standards. Potatoes and tomatoes contain toxic glycoalkaloids, which have been linked to spina bifida. Kidney beans contain phytohaemagglutinin and are poisonous if undercooked. And dozens of people die each year from cynaogenic glycosides from peach seeds. Nevertheless, scientists working on GMOs have used strict scientific principles and thorough analyses to confirm for themselves and the public that the genes and techniques used are safe for the consumer and for the environment.
To cite an example of misrepresentation of facts, in a recent paper Ho et al questions the safety of the Cauliflower Mosaic viral promoter used in many transgenic plants. It is estimated that about 10% of all cabbages and other brassica are infected with this virus, so every time we eat cabbage we consume 10,000 more total virus particles than would come from the same amount of transgenic plant material. Also no potential for dangerous activities of new combinations involving 35S promoter parts could be postulated that would be different from the potential present in the cells already. All elements in the promoter exist already in plant cells. Every banana variety examined has integrated viral sequences from a CaMV-related pararetrovirus and most people eat uncooked bananas. Ho cites a Swiss publication that shows that horizontal gene transfer does not occur even under selection pressure, as evidence for such a transfer. Ho also noted that cauliflower mosaic virus is similar to retrotransposons. It is becoming increasingly apparent that a significant proportion of plant genomes are made up of retrotransposons. Perhaps we should have a moratorium on eating plants!
The most that we can ask is that all foods produced by whatever method receive the same level of evaluation both with regard to impact on the environment, and safety to the consumer. Millions of people have already eaten the products of genetic engineering and no adverse effects have been demonstrated. Scientists are confident in the scientific validity of the systems that regulate and oversee the American food supply. They are equally confident that if we abandon the scientific process in judging the safety of the food supply, we will slow or destroy the advances that will reduce the use of unsafe chemicals and agricultural practices in this country and we will limit the wonderful potential of improved nutrition and quality that promise to strengthen the agriculture economies in the U.S.A. and around the world.
As noted by former U.S. President Jimmy Carter, "Responsible biotechnology is not the enemy; starvation is. Without adequate food supplies at affordable prices, we cannot expect world health, or peace."
For more information: Martina McGloughlin, Director, UC Davis Biotechnology Program. Tel: 530-752-3260. Email: mmcgloughlin@ucdavis.edu.