INTRODUCTION / BACKGROUND

In this decision case, a congressional staffer must weigh a number of competing needs, including the popular reactions to genetically modified organisms (GMOs) and the need to eliminate vitamin A deficiency, in deciding how to present information to her boss, an influential congressman drafting legislation to support agricultural research. The case explores the social and biological issues surrounding micronutrient malnutrition, including deficiencies of several vitamins and essential minerals, especially iron, iodine, and vitamin A. These problems, which have been referred to as "hidden hunger," affect at least one-third of the world's population, but their occurrence is confined mainly to developing countries where they typically affect twice that fraction of people and contribute to half of all child mortalities. The case deals with the nature and causes of hidden hunger and why these problems persist despite the gains in food production made by the "Green Revolution." Using vitamin A deficiency as the exemplar, the case addresses possibilities for preventing micronutrient malnutrition.

Golden Rice^TM is discussed as an example of a product that might be used to address the prevalent vitamin A deficiency in developing countries. According to some, this rice offers the possibility, by providing an available source of vitamin A in a major staple food, of reducing each year hundreds of thousands of cases of corneal blindness and death due to infection among children in poor, rice-eating countries.

I prepared this case for use in a graduate-level seminar, "Genomics, Agriculture, Food Systems and Development," at Cornell University. The dozen students in the course also included several undergraduates. Only a few students came from biological disciplines; most were social scientists. The case is used late in the semester as part of a series of classes led by various professors dealing with the issues surrounding genomic applications in agriculture and their implications to health, environmental stewardship, economic sustainability, and national development.

Objectives

• To learn about the prevalence and nature of micronutrient malnutrition in the developing world.
• To examine the nutritional aspects of pro-vitamin A carotenoids in foods, the physiological functions of vitamin A, and the health consequences of chronic vitamin A deficiency.
• To understand the "food systems" perspective on malnutrition.
• To explore how the tools of molecular genetics are used to produce transgenic crops.
• To learn about Golden Rice and the controversy surrounding it.
• To gain a better understanding of the needs for sustainable solutions to problems of malnutrition.

BLOCKS OF ANALYSIS

While the case ostensibly deals with funding agricultural research through the USDA, the underlying concern is related to the research priorities that the American public has a vested interest in supporting. This topic involves the health impacts and the opportunities of a transgenic crop to address the problem of vitamin A deficiency. The specific issues are addressed below.

Micronutrient Malnutrition

The Green Revolution, an international movement that believed malnutrition in developing countries was caused mainly by protein and food energy deficiencies, succeeded in substantially increasing food production in poor countries by focusing on the major staple grains: rice, wheat, and maize (corn). These cereal crops were viewed as the best source for increasing food energy and protein. However, cereals provide few nutrients other than calories and protein, and milling (in the case of rice and wheat) removes most of their vitamins and minerals. The availability of new, high-yielding varieties (HYVs) of rice and wheat have been attractive alternatives to the more nutrient-balanced pulse (grain legume) crops, which are highly dependent on the weather and, thus, present greater risks to farmers. This benefit has led to widespread adoption of HYVs, reducing the diversity of major cropping systems and the production of micronutrient-dense pulses. Thus, while the Green Revolution is credited with averting the wide-scale food shortages and attendant protein-energy malnutrition that seemed imminent in the 1960s, their effort did not address (and may even have contributed to) deficiencies in such micronutrients as iron, zinc, and vitamin A, which have recently emerged as major public health problems—now referred to as "hidden hunger."

Vitamin A Deficiency

Severe vitamin A deficiency leads to dryness and ulcerationof the cornea—a condition called xerophthalmia. Even modest deficiencies can increase morbidity and mortality from infectious diseases by impairing immune function. Animal products contain the only pre-formed vitamin A (i.e., retinol) in normal diets. These foods tend to be expensive and, therefore, beyond the reach of poor people in developing countries. Some plant foods, particularly yellow and orange fruits and vegetables, can be good sources of pro-vitamin A carotenoids (i.e., - and -carotenes), which yield retinal metabolically. Using such carotenoids as sources of vitamin A depends upon adequate cleavage of the carotenoid and absorption of the retinol product. These processes appear to be inefficient, particularly among poor children who may have very low intake of fat required for retinal absorption and may also suffer from enteritis, diarrhea, intestinal parasites, and infections, all of which impair the enteric absorption of retinal. To date, vitamin A deficiency alleviation programs have followed a medical model of oral vitamin A prophylaxis. These require substantial inputs of labor and money, making poor countries dependent on rich ones to sustain such programs.

Food Systems

The "food system" concept involves all activities relating to the production, acquisition and utilization of foods and the nutrients contained in foods. Food systems can be seen as converting basic resources (land, nutrients, labor, etc.) into a number of outcomes, including the health and well-being of the people in the system who are both its operators and operands. Micronutrient malnutrition is the failure of food systems to produce adequate supplies of all essential nutrients in accessible and biolgically available forms. Food system models can identify methods of addressing malnutrition in sustainable ways at the root of the problem.

Genetic Engineering of Crops

Biotechnology refers to the various methods, using plants, animals or microbes, to modify an existing species. Genetic engineering is the term for the biotechnological process in which the traits of an organism are changed by transferring individual genes from one species to another or by modifying genes within a species. Today's domesticated plants and animals are the result of selective breeding and are, thus, "genetically improved" for such traits as yield, disease resistance, and pest resistance. The the term "genetically modified organisms" (GMOs) refers only to organisms produced by genetic engineering. The only GMOs currently available to farmers are those used for pest control: soybeans, cotton, corn, and canola engineered for resistance to an herbicide; and corn, cotton, and potatoes engineered to produce bacterial proteins that are toxic to insects. Genetic engineers can insert new genes ("transgenes") into an existing plant genome by particle bombardment of target nuclei (using the "gene gun") or using of a recombinant plasmid (Agrobacterium tumefaciens). Many countries (particularly, developing countries). however, strictly regulate the ways in which transgenic crops are grown and evaluated. Both the techniques and products of genetic engineering are intellectual properties protected by international patent agreements.

Golden Rice

Rice is the major staple for a third of the world, including more than a billion people living in South Asia where vitamin A deficiency is endemic. Rice contains no pro-vitamin A carotenoids; however, such traits were incorporated into the new transgenic rice, Golden Rice, which contains -carotene in its endosperm (not lost in milling). The -carotene trait was added by incorporating into the rice genome a number of genes and DNA fragments from bacteria and the daffodil. Some 70 patents were involved in the development of Golden Rice, which is undergoing further research at the International Rice Research Institute (Los Banos, the Philippines). The aim of its producers is to make Golden Rice available free of charge to farmers in poor countries, but experts believe that farmers will only adopt Golden Rice if it is agronomically superior (in productivity, disease resistance, etc.) to currently available HYVs. Several questions exist about the actual vitamin A-biopotency of Golden Rice because of such factors as its current -carotene content, storage losses in -carotene, and what is thought to be fairly low -carotene-to-retinol conversion efficiency by at-risk children in poor countries. The adoption of Golden Rice will also depend on consumers accepting a traditional food of a different color, something that has been a barrier in several countries. (For this reason pro-vitamin A-containing yellow maize has been difficult to introduce in sub-Saharan Africa.) There is also growing political resistance to GMOs (a.k.a. "frankenfoods"), as well as skepticism that Golden Rice may be merely an attempt by the biotech industry to salvage its reputation, which was sullied by its initial efforts to develop herbicide- and pesticide-resistant crops. Products such as Golden Rice do not address the fundamental problems underlying vitamin A deficiency and other forms of micronutrient malnutrition: poverty and lack of dietary diversity.

CLASSROOM MANAGEMENT

The seminar in which I have used this case meets weekly in a three-hour session. By the time this case is used (late in the semester), the students have acquired a good working understanding of the methods of and issues surrounding biotechnology, yet they tend to have only a superficial understanding of nutrition and health relationships, particularly in the developing world. Therefore, I use the first 30 to 45 minutes of the class session to present in an informal lecture format the key technical aspects of vitamin A (chemical structure, metabolic roles, clinical signs of deficiency, etc.). I include in my presentation my own pictures of South Asian children with corneal damage (Bitot's spots, xerosis, xeropthalmia). Few, if any, of our students have ever seen such cases before. I find that introducing them in this way to the human impact of vitamin A deficiency helps sensitize them to their own tendencies to deal with unfamiliar problems abstractly, as represented by Campbell Hurst in the case. I expect students to have prepared for the class by reading the case and supporting readings (see "References" below), all of which are distributed at the beginning of the semester.

I open the discussion of the case by asking why Cindy is inclined to spend any time at all thinking about Golden Rice—after all, there's no rice grown in North Dakota, so why will Mr. Pomerantz's constituents care at all about it? As the discussion progresses, I ask such questions as: "If agriculture has been so successful, why does malnutrition persist?" "How are Campbell/Mr. Pomerantz likely to react to that idea?" "Why does vitamin A deficiency appear to be limited to South Asia, sub-Saharan Africa, and Latin America?" "Where do you get your vitamin A?"

This approach inevitably leads to a lively discussion about what Cindy experienced in the Peace Corps, why preventing malnutrition overseas is in the domestic interest of the United States (e.g., by improving foreign markets, by reducing needs for foreign aid, etc.), the ethical imperative of helping others in need, and the American political process. Because the students come to this class from different academic backgrounds, the discussion tends to be enriched by the usually different perspectives of economists, plant scientists, sociologists, etc. If necessary, I make technical points about cropping systems, food habits, health situations, and/or childcare practices in that part of the world. Anticipating this, I also have a large PowerPoint file of agricultural, food, and health data for South Asia to support particularly important points.

This is a lot of material to bring together in a single discussion, but it works very nicely with a small group of enthusiastic and committed students. Because my students are not nutritionists, I believe that the introductory "mini-lecture" is very useful in bringing them to a common point of understanding about some of the health aspects of this case.

I do not try to bring the discussion to consensus on what course Cindy should take. Instead, I wish my students to leave the class continuing to think about the issue. A good follow-up written assignmen is for students to describe what Cindy did at the staff meeting.

I believe that this case can be useful in undergraduate and certain non-science courses. Such classes would call for a more extensive and formal way of addressing the technical aspects of the nutritional and biotechnological issues underlying the case. This could be accomplished using multiple class sessions, e.g., using a class or two to focus on the nutrition and biotechnology, and a final session to focus on Cindy's decision. The instructor's development of concise and accurate graphics to present the science of this case in an understandable way will be key to adapting it for use with students with limited backgrounds in these areas. At the same time, non-scientists will bring important perspectives not unlike those of many Americans. These views are valuable to the discussion of this case and can be likened to those of Mr. Pomerantz's constituents to whom he must justify his action.

On a final note, I have been surprised to find that even the most vigorously "anti-GMO" students tend to support the application of biotechnology in developing Golden Rice. They frequently say that they see this GMO as being socially responsible and relatively free of the environmental concerns surrounding other agricultural applications.

REFERENCES

Readings Assigned to Prepare for the Class

1. Ye, X., Al-Babili, S., Klöto, A., Zhang, J., Lucca, P., Beyer, P, and Potyrkus, P. (2000) Engineering the Provitamin A (-carotene) Biosynthetic Pathway into (Carotenoid-Free) Rice Endosperm. Science 287:303-305.
    
2. Guerinot, M.L. (2000) The Green Revolution Strikes Gold. Science 287:241, 243.
    
3. Combs, Jr., G.F., R.M. Welch and J.M. Duxbury. 1998. Revealing Hidden Hunger: Solving the Micronutrient Famine. The World & I, April: 174-181.
    
4. Nash, J.M. 2000. Grains of Hope.
   http://www.time.com/time/archive/preview/0,10987,1101000731-50576,00.html
   (Free preview, full article viewing requires subscription to Time Archive.)
    
5. Environmental News Network: Debate Steams Over Golden Rice (April 4, 2001)
   http://www.enn.com/news/enn-stories/2001/04/04042001/rice_42868.asp

Other References

1. Combs, Jr., G.F. 1998. Vitamin A, Chapter 5 in The Vitamins: Fundamental Aspects in Nutrition and Health, Academic Press, New York, pp. 107-153.
    
2. Institute of Science and Society: The "Golden Rice"—An Exercise in How Not to Do Science.
   http://www.i-sis.org/rice.shtml
    
3. Scientists Rebuke Critics of Golden Rice: Biotech Rice Can Benefit Developing World.
   http://www.agbioworld.org/biotech_info/pr/rebuke.html
    
4. World Bank: Golden Rice for World's Poor.
   http://www.worldbank.org/developmentnews/archives/html/jan18-21-00.htm

Acknowledgements: Publication of this case study on the National Center for Case Study Teaching in Science web site has been made possible with support from The Pew Charitable Trusts.

Date Posted:  10/05/02 nas
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