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4 The Promise of QPM GENERAL CONCLUSIONS Quality-protein maize (QPM) appears to be an outstanding product. From current evidence, there seem to be no fundamental technical uncertainties still to resolve. In their remarkable research, scientists at the Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) have overcome or minimized the problems that formerly discredited opaque-2 maize: low yield, low acceptability, high disease suscepti- bility, slow drying capabilities, and poor storage qualities. Thus, in principle, QPM should be as acceptable and as inexpensive as common maize, and its nutritional advantage should come at little or no penalty to the farmer or consumer. Whether the world needs quality protein is not as evident as it seemed when opaque-2 maize was developed in the early 1970s. However, despite uncertainties expressed by some nutritionists, the panel expects major health benefits to be derived from QPM. QPM carries the promise of creating both better food and more food, and of producing quality protein without sacrificing carbohydrates and calories. Over the long term, QPM should benefit tens of thousands of maize-reliant communities and millions of poorly nourished people. In a sense QPM is nutritionally risk-free. If its present performance remains stable or is further improved, its use requires that nothing be given up. Switching from common maize to QPM demands no sacrifice of yield, money, calories, or nutrients. The only difference between QPM and common maize is a reorganization of proteins that in QPM emphasizes more nutritious subtypes (see chapter 6). INTRODUCING QPM The promise of QPM is probably greatest in areas of the world where people depend on maize, sorghum, or root crops to feed young 35
36 QUALITY-PROTEIN MAIZE children. In other areas where meat, milk, or highly digestible legumes are readily available at a low price and are routinely fed to the young, there is less concern about the protein quality of maize. However, where these quality-protein sources are scarce, expensive, or tradi- tionally withheld from small children, there are powerful reasons for testing QPM. Happily, it is not really a new crop. Millions of people are accustomed to growing and eating maize. QPM demands no unexpected inputs of fertilizer, pesticides, irrigation, or agronomic practices. And QPM should require little or no change in eating habits and almost no modification of the food-supply system. In this, it differs from previous approaches to relieving protein shortages, which usually involved the introduction of exotic legumes, algae, or food supplements that de- manded substantial changes in personal eating habits or national food supply. QPM is expected to perform well under a wide range of conditions. It was created in a process that shuttled seeds back and forth between a "good" growing site and a "poor" one (see chapter 7). Only seeds from progenies that could survive both conditions were advanced. This, together with maize's broad adaptability, means that QPM should demonstrate tolerance to harsh conditions and poor management. QPM and Children Some nutritionists doubt whether the introduction of any type of maize in infant feeding should be advocated. However, if maize is already being used in this way, then QPM should not make the situation worse, and in fact seems likely to improve it. For millions of children in Latin America and Africa, there are particularly auspicious prospects for QPM. There, maize and low-protein root crops tend to make up much of an infant's diet. Metabolic-balance studies have already shown that children who consume maize as the only source of protein increase their nitrogen retention by 50-100 percent when they switch from normal maize to nutritionally improved maize.1 Such increases should translate into equivalent rates of weight gain, lean-body-mass growth, growth in stature, and protection from the manifestations of protein deficiency. QPM is likely to have special importance for use in weaning foods, catch-up growth, and improving birth weights: Weaning foods. Nutritionists agree that wherever people depend on cereals alone or cereals and beans for weaning children, QPM is likely to produce benefits. For the fully weaned infant, the new grain should satisfy protein needs while satisfying a reasonable amount of calorie 1 Viterietal., 1972.
THE PROMISE OF QPM 37 needs. For partially weaned babies it should also be beneficial.2 Thus, in the age groups from about four months to three years, it should reduce mortality from malnutrition and improve growth rates among societies whose dietary staple is maize. Catch-up growth. For children trying to recover growth after being malnourished or sick, QPM should also be valuable. Their protein requirements are proportionately higher than normal. For many, they are so high that protein becomes limitingâparticularly in the youngest, and notably after episodes of diarrhea. Improving birth weights. As mentioned, a prime cause of infant death is low birth weight. A principal contributory factor is the mother's own low level of nutrition, and the use of QPM during pregnancy could raise levels of child survival. Low birth weight is associated with 30-40 percent of the millions of infant deaths in the developing world. In many countries, food supplements for "at-risk" pregnant women have been shown to be effective as a preventive measure. QPM should be at least as good. QPM and Beans As noted, maize is often consumed with beans. The beans contribute lysine, tryptophan, and niacin, and the combination would seem to give QPM little nutritional significance. However, beans are more expensive to buy than maize; they cost more to grow and they yield less. Also, they require long cooking time, which is a problem as firewood becomes increasingly difficult to find. Moreover, since high- yielding cereals were introduced in Latin countries, bean production has decreased, whereas maize production has increased. In addition, beans are not consumed every day. Also, beans are difficult to digest by very young children. Throughout much of Latin America, for example, parents withhold beans until a child is at least two years old. Thus, during the most vulnerable growth period, children often need lysine and tryptophan, even if the rest of the family is eating a steady diet of beans. The same is probably true in India and Pakistan, where people eat chickpeas, lentils, and pigeon peas (dahl), which are also not fed to the youngest children. The same may also be the case in parts of Africa, where cowpeas are the chief legume supplement. In summary, therefore, even those who eat beans and other legumes should get a more balanced diet with QPM as their cereal rather than common maize. 2 Despite the overwhelming value of breast feeding, there is growing recognition that it is important to use weaning foods to supplement mother's milk after about the age of four months. At this time the breast-milk supply can fall short of the growing infant's demands for protein and energy. Information from S.N. Smith. Also see Waterlow and Thomson, 1979.
38 QUALITY-PROTEIN MAIZE A Nutritional Safety Net In a broad sense, QPM could provide a nutritional safety net for a country, valley, village, or family, even if it is not vital for everyone. In a child's diet, it provides more latitude for error where beans or other foods are used to supplement local carbohydrate staples. Indeed, for all of the population, the switch to QPM from normal maize makes any dietary irregularity less important, and any reliance on legumes or other supplements less crucial to health. In remote areas, especially those not accessible by mass transportation, it could provide children a nutritional security that could be sustained by local effort without reliance on the outside world. Even where there is no visible malnutrition, the presence of QPM could be important. Fiscal, political, fuel-supply, or agricultural crises often bring cutbacks in services. Indeed, even countries with praise- worthy commitments to the poor have been forced to stop funding social services, dismiss schoolteachers, reduce food subsidies for pregnant mothers and children, close clinics, and halt immunization programs for lack of funds, foods, fuel, or spare parts. It should be understood that QPM's benefits do not merely double the level of effective maize protein. People actually show better use of all proteinsâno matter what the source. This is because malnour- ished bodies use poorly even the small amount of nutrients they may get. Malnourished children, for instance, void much of their meager protein in their urine. If fed QPM, this wastage can be minimized or stopped. Indeed, improving a person's overall nutritional status means that bodies absorb all nutrientsâvitamins, iron, and other mineralsâ more easily. Moreover, as noted earlier, a diet of quality protein stimulates appetite. Economic Development The normal way to measure a crop's yield is in kilograms per hectare, but with QPM there is an additional level of yield: the amount of nutrients produced per hectare. With this new crop, productivity can actually be expressed in terms of the efficiency of feeding people. In this sense, the nutritional benefits of QPM have broad implications for economic development. For instance, each gram of QPM gives the same amount of usable protein as at least two grams of normal maize. By extension, therefore, QPM makes maize farming at least twice as efficient in terms of protein production. Or, said another way, half the land area can fulfill an individual's protein requirements. It has been calculated, for instance, that in Guatemala it takes 0.013 hectares to feed a child for a year with QPM, whereas it takes 0.035 hectares to feed that same child with ordinary maize. For adults, the relative advantage is less because adults have lower protein require-
THE PROMISE OF QPM 39 ments than children, but the conclusion, nevertheless, remains that QPM makes maize production more efficient.3'4 Animal Feed QPM has a clear and certain value in livestock productionâ particularly where soybeans or fishmeal are expensive or unavailable (as in the maize-producing regions of West Africa). Young animals require diets higher in protein than young people.5 In most locations, substituting QPM for soybeans or fishmeal will reduce the cost of feeding livestock. However, the protein in QPM is not as concentrated, so that some supplements will probably still be needed. Nonetheless, using QPM is likely to make the production of animals (particularly pigs and chickens) more efficient. Indirectly, this will improve human diets by providing more meat and eggs. For some countries it could also reduce the foreign exchange paid out for imported feeds. Nutritional Supplements Several countriesâBolivia, Peru, Panama, Colombia, and a number of African nations, for instanceânow make nutritional supplements based on mixtures of food legumes, cereal grains, and oilseed cake. These countries might particularly benefit from QPM. In Central America, a pioneering supplement, Incaparina, has been a notable success, and its sales are rising throughout the region. First produced following the 1966 earthquake in Guatemala, when food was limited, it incorporated 3 percent yeast as a quality-protein ingredient. Later, as yeast became too expensive, lysine was substituted. Now lysine has also become too expensive, and the formulation is currently being modified to incorporate QPM. In addition, Incaparina's producers are experimenting with removing the starch from QPM to produce a protein concentrate. This has a nutritional makeup similar to that of an oilseed meal. Indeed, QPM protein concentrate is soon expected to replace cottonseed meal in the Incaparina formulation. Snack Foods QPM is especially promising for tortilla chips and other maize-based snack foods. The snack-food industry is perennially charged with 3 Bressani and Elias, 1979. 4 Because conventional maize and QPM have roughly equal contents of protein, carbohydrate, and fat, their formation requires the same amount of sunlight. It costs the maize plant virtually no additional photosynthetic energy to produce lysine and tryptophan than to produce more common amino acids. 5 People grow relatively much more slowly. A 4.5 kg piglet may gain 450 g per day (10 percent of its body weight), a 30 g baby rat gains 3-4 g per day (10 percent), but a 4 kg infant gains only about 30 g per day (1 percent).
40 QUALITY-PROTEIN MAIZE peddling "junk food" of little nutritional value. The soft, floury kernels of opaque-2 maize did not lend themselves to the standard methods used in producing commercial snack foods. However, the kernels in QPM are likely to be suitable. Using QPM might provide both a nutritious product and an important public relations benefit. (For more information see appendix A.) RECOMMENDATIONS In any scientific development there is a time for caution and a time for boldness. The panel is convinced that with QPM the time for action has arrived. QPM should be field tested quickly. It has been produced by the dedicated efforts of a small research team in the face of worldwide abandonment and at low budget. Now is the time for researchers to help assess QPM in the "real world" situation of farmers and mal- nourished people. Although QPM has shown outstanding promise, to date it is only a promise. Any lingering doubts need to be rapidly resolved by an organized, international, cooperative effort. Testing QPM in national maize-breeding programs is vital, especially in countries with high incidences of malnutrition. Areas of the world that should be targeted are those where people depend heavily on maize to feed small children; for example, the highlands of the Andes, Central America, most parts of Africa, and select countries of Asia, including Bangladesh, Indonesia, and the Philippines. QPM has promise, too, in areas where people could be persuaded to use it instead of their current cassava, plantain, sorghum, or other inferior-protein staples. All over the world, low-income populations are increasing their dependence on cereals. With its good yields and high nutritional quality, QPM could become a powerful means for helping them become less vulnerable to malnutrition. As noted, maize is often the crop of the poor, and in the maize-growing areas of the world, millions of children living in poverty are not thriving. Here is an opportunity to explore this new approach to relieving an intolerable situation. There is every reason to expect health benefits, particularly in weanlings and malnourished infants. QPM has the advantage in that it allows a country to combat such dietary deficiencies by using its own farmers and resources. Indeed, in most areas, it should allow a family to combat its own malnutrition without outside help.
