March 1, 2011

Two Cents: The GMO Debate

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The Sun recently published a series of opinion pieces debating the pros and cons of genetically modified organisms. In the interest of fostering further dialogue on the issue, The Sun solicited the opinions of several knowledgeable professors on the topic.The Sun recently published a series of opinion pieces debating the pros and cons of genetically modified organisms. In the interest of fostering further dialogue on the issue, The Sun solicited the opinions of several knowledgeable professors on the topic — in what will be the first in a series of debates on a host of controversial matters. The aim is to present a sampling of views, which in no way will be entirely comprehensive, but will hopefully allow readers to learn about different topics from a variety of perspectives and disciplines.

What are genetically modified foods?

“Much of the form and function of a plant is encoded by the DNA in its cells. When you eat either a genetically modified plant or an organic one, you are also eating its DNA. Knowing the code of a specific gene in a plant, or the code of a plant’s entire genome, allows us to observe and understand this source of variation in plant form and function. Two common types of DNA variations are often detected. First, differences in the code for a gene arise due to mutations in the DNA   resulting in alleles or different forms of a gene. The second is diversity in which alleles are strung together to comprise the plant’s genome and brought together by pollination of the parent(s). Transgenic or genetically modified plants (G.M.O.s) contain a specifically targeted change in a gene or an insertion of an entirely new gene into a genome.” –– Prof. Mazourek, plant breeding and genetics

Lack of FDA Regulation

When on sabbatical in Washington, D.C. in 2002, Prof. David Pelletier, nutritional sciences, explored the scientific and legal basis for the U.S. Food and Drug Administration’s regulations on genetically engineered food. Two categories exist for food regulation: food additive and food adulteration. As described by Pelletier, the food additive category is more preventive in orientation and requires publicly available testing, documentation and approval before a food goes to market, while the food adulteration clause allows the FDA to respond to unexpected events that happen at some point before and after a food goes to market. From a strictly legal perspective, the FDA chose to give genetically engineered foods (as a class) the presumption of being Generally Regarded as Safe (GRAS), and thereby subject only to the adulteration clause.The dilemma is, G.E. foods do meet the legal definition of a food that needs to be regulated under the food additive clause, but in 1992 (and to this day) we do not have adequate tests for producers to assess the safety of the varied unintended compositional changes that can occur in G.E. foods. “The pro-G.E. scientists typically give the example, ‘picture a string of yellow beads representing a strand of DNA in the cells of a food and having one bead replaced with a red one. This bead will produce the intended new protein. It only changes one thing in the food.’ However, we now know that the insertion of one gene can disrupts the functioning of dozens or even hundreds of other genes throughout the genome. It’s not beads on a string, but more like a spider web, if you pull on one part, it affects other parts.” “None of this means G.E. foods are not safe –– it means we don’t have good methods for testing them. It also needs to be recognized that the FDA does not require foods from other technologies to undergo such testing.” Interestingly, Pelletier’s research documented that from 1994-2004, 21,936 USDA research projects were funded in all areas of food research, but only 19 of these had the keywords of “plants, biotechnology and allergens,” and most of these were devoted to detecting or reducing the risks from known allergens. To date, no such research initiative has been launched. Another problem is that there is no requirement that G.E. foods be labeled, so it is not possible to do epidemiological studies to see if there are any adverse consequences of consuming G.E. foods. Most disturbing to Pelletier is the way in which the policy was developed. He said the FDA did not request input on its draft policy statement from an expert committee of the National Academy of Sciences, nor did it consult any of its advisory committees. “My beef isn’t with genetically engineered food; it’s with the process FDA used to formulate its policy, which was an inside job from beginning to end and even disregarded the concerns of senior FDA scientists.”–– Interview with Prof. David Pelletier, nutritional sciences

G.M.O.s and Feeding the World

“The world’s population is currently about 7 billion and it expected to grow to 9 billion by 2050.  Today, according to the Food and Agriculture Organization of the United Nations, there are more than 900 million undernourished people in the world. The FAO defines undernourished as lacking sufficient calories to meet energy requirements.  In addition, more than 2 billion people, mostly children and women, are iron deficient and an estimated 6,000 children die every day from vitamin A malnutrition.

One strategy for addressing the problem of micronutrient malnutrition (vitamin and mineral deficiency) is biofortification of staple food crops such as rice, wheat, maize, sweet potatoes and beans.  Biofortification is the use of biotechnology to enhance the content and/or bioavailability of vitamins and minerals in foods.  One well-known and promising example of a biofortifed food is golden rice.  Golden rice was developed using genetic engineering to program rice plants to produce beta-carotene in the rice kernels. (Beta-carotene is converted to vitamin A in the body.) This means that conventional plant breeding cannot be used to increase beta carotene in rice kernels, leaving genetic engineering as the only alternative for breeding biofortified rice.   Rice provides as much as 80 percent of the calories in the diets of the poor in many areas of the world and vitamin A deficiency is often prevalent in rice eating areas.  I don’t believe that genetic engineering alone can save the world from hunger and malnutrition but I do think it is one of many strategies and technologies that we must pursue if we are to have any hope of feeding the 9 billion people who will inhabit out planet by 2050.  All technologies we develop carry risks but I believe we must be willing to take some risks because the alternative is the status quo with millions of people suffering terribly from hunger and malnutrition.”  –– Prof. Dennis Miller, food science

Public Perception of G.M.O.s Abroad

Prof. Ronald Herring, government, has done extensive research on genetically modified organisms and their use and impacts in India.   In 2008, Herring wrote an op-ed for The Hindu regarding the misconceptions of the effects of G.M.O.s on Indian farmers. Herring writes, “There is a great puzzle here. If disastrous in 40 countries, why does the technology spread so rapidly across nations and farms? Recombinant DNA technologies represent perhaps the most rapid adoption of any agricultural technology in history. Are farmers irrational, ignorant, duped? The subaltern famously cannot speak, but can she not count either?”Herring continued, “There is then no puzzle of farmers adopting disastrous technologies: the disasters exist entirely in the imaginary of advocacy networks that have interests in disasters. The acceptance of molecular breeding technologies is rooted in precisely the agency and rationality of Indian farmers denied in global narratives of G.M.O. opponents. Neither duped nor innumerate, cotton farmers face extreme challenges — from climate change to globally rigged markets — but they do know what works in their fields.”Prof. Herring teaches CSS 4100: The G.M.O. Debate: Science and Society, along with Profs. Peter Hobbs and Janice Thies, crop and soil sciences. Though the science behind genetically modified foods is not Herring’s academic focus, he shared his thoughts on the subject. When asked about the safety of G.MO.s, Herring responded, “There are studies that show that the transcriptomic errors introduced by other means of plant breeding considered ‘conventional’ are greater than those made by recombinant DNA breeding. The question is whether there is more or less risk in genetically engineered plants as opposed to breeding techniques we think of as conventional, that have been normalized. Most important is mutagenic plants, which are bred by taking a traditional cultivar and inducing mutations by radiation or chemical agents called mutagens.  Here’s the critical point: only recombinant DNA plants –– where genes are spliced together –– are considered ‘G.M.O.s’ and subjected to special scrutiny.”–– Interview with Prof. Ronald Herring, government

Pesticides, Organics, and Comparative Breeding

Prof. Elizabeth Earle, plant breeding and genetics, challenged the assertion of the Feb. 15 opinion piece “Rejecting Genetically Mod­ified Food” that G.M.O. crops can cause resistance to pesticides. “Other genetically modified foods are made to resist insect attack, like BT crops, reducing the use of pesticides. Therefore, they cause the introduction of fewer toxic chemicals in the environment. Consumers ought to be pleased about that.”“One of the big arguments about G.M. crops is the problem it creates for organic growers. Organ­ic growers decided themselves that being organic would mean having only a small percentage of their crops as G.M. There are G.M. crops that could be considered favorable for the environment.”Finally, food safety remains a contentious aspect of using G.M. plants. “People have been eating G.M. foods in this country since 1996,” Earle said. “Everything I’ve seen on food safety points to the safety of G.M. plants.”Earle cited a survey recently published in Plant Physiology that examined 44 microarray studies comparing genetically engineered (G.E.) crops to non-G.E. crops. The authors concluded that there are fewer changes in the plant genome ––­­ in the overall expression of genes and proteins –– of G.E. crops compared to changes caused by traditional breeding or environmental conditions, like drought. “This indicates that the overall changes to the plant genome by G.M. are smaller than the natural variation caused by traditional breeding.”––Interview with Prof. Elizabeth Earle plant breeding and genetics

Original Author: Sun Staff