Food from Dryland Gardens - An Ecological, Nutritional, and Social Approach to Small Scale Household Food Production (CPFE, 1991) Part I - Gardens as a development strategy (introduction...) References 2. Gardens and nutrition in drylands (introduction...) 2.1 Summary 2.2 Recommended dietary allowances and the nutrient content of foods 2.3 Special nutritional needs in drylands (introduction...) 2.3.1 Children’s Special Needs 2.3.2 Women’s Special Needs 2.3.3 Work 2.3.4 Illness 2.4 Energy 2.5 Protein 2.6 Vitamins (introduction...) 2.6.1 Vitamin A 2.6.2 Vitamin D 2.6.3 Vitamin C 2.6.4 Folacin 2.6.5 Thiamin (B1) 2.6.6 Riboflavin (B2) 2.6.7 Niacin 2.7 Minerals (introduction...) 2.7.1 Iron (Fe) 2.7.2 Zinc (Zn) 2.7.3 Calcium (Ca) 2.8 Fats 2.9 Fiber 2.10 Anti-Nutritients 2.11 The effects of gardens on nutrition (introduction...) 2.11.1 Nutrient Yields from Gardens 2.11.2 Effects on Nutrition 2.12 Resources References 3. Gardens, economics, and marketing (introduction...) 3.1 Summary 3.2 People, households, and economics (introduction...) 3.2.1 Production Efficiency 3.2.2 Economic Rationality and Risk 3.2.3 Control of Resources: Individual or the Group? 3.2.4 Economic Development and Well-Being 3.3 Garden economics (introduction...) 3.3.1 Garden Yields 3.3.2 Income and Savings from Gardens 3.3.3 Household Well-Being 3.4 Marketing garden produce (introduction...) 3.4.1 Women and Marketing 3.4.2 Risk, Investment, and Return 3.4.3 Cooperation 3.4.4 Garden Income and the Household 3.5 Resources References 4. Assessment techniques (introduction...) 4.1 Summary 4.2 Assessment, monitoring, and evaluation 4.3 From whose point of view? (introduction...) 4.3.1 Assessment and Collaboration 4.3.2 Representativeness 4.3.3 Insiders and Outsiders 4.3.4 Participant Observation 4.3.5 Gardens for Whom? 4.4 What do existing gardens tell us? 4.5 Interviews (introduction...) 4.5.1 Composing Questions 4.5.2 Translating and Back-Translating 4.5.3 Choosing a Sample 4.5.4 Pretesting 4.5.5 Conducting the Interview 4.5.6 Coding, Checking, and Analyzing 4.6 Seasonality 4.7 Food distribution and consumption 4.8 Maps 4.9 Long-term trends 4.10 Outside sources 4.11 Resources References

Food from Dryland Gardens - An Ecological, Nutritional, and Social Approach to Small Scale Household Food Production (CPFE, 1991)

Part I - Gardens as a development strategy

A vast part of the world’s population suffers from poverty, malnutrition, and environmental degradation,¹ and gardens are often a part of peoples’ struggle to cope with these problems. Gardens contribute a great deal to the nutritional, economic, and social well-being of dryland households, and they have the potential to contribute much more. Why then do so many garden projects fail? In many cases the answer is because they start out by establishing a model garden and trying to convince local people to adopt the model without first understanding existing local gardens, resources, or knowledge.² Whether intentional or not, this reflects an assumption that the project workers know more than people in the community, and that learning will be a one way process with the project providing the answers. This is an example of the “top-down” approach to development.

The Top-Down Approach to Development

We believe that to be sustainable, development that involves outsiders must be a cooperative venture. Local people guide this process and project workers are resources for them. Community members must take pride in themselves, demand control of the changes affecting them, and work with and learn from project workers as equals. Project workers, especially those from outside, must also learn to work with community members as equals, while recognizing that the local people must guide the project’s direction. Project workers must respect and support local skills and knowledge, and always keep in mind the ultimate goal of improving people’s well-being in a way that is both socially and environmentally sustainable. Gardens that support self-sufficiency by using local resources, improving nutritional status and incomes, and protecting the environment, can make an important contribution to finding solutions.

Development is Cooperation Between Equals

Model gardens are gardens that are developed without regard to the local circumstances where they are to be promoted. They are what someone from outside the community believes gardens should be. Model gardens are often inappropriate in many ways. They may require more time, water, or land than local people can afford, use seeds and techniques that are not locally adapted, or produce foods that people do not like. Promoting model gardens also ignores both local gardening skills and local gardening problems.

There are some distinct approaches to household gardens for improved well-being that reflect different values in the field of development. These approaches can be most usefully distinguished according to whether they are based on models brought in from the outside, or are built on local, indigenous knowledge. Today agriculture, nutrition, health, and rural development projects often promote gardens in recognition of their potential contribution to household well-being, but frequently these projects promote an industrial garden model which is very different from the gardens already existing in the area. Industrial gardens are based on agriculture in industrial countries and include crops, tools, inputs, production techniques, marketing organization and nutrition education which are usually inappropriate for the local situation in the Third World, and are not sustainable.

A much less common development approach is to support indigenous gardens, those that are developed by the gardeners themselves, based on local knowledge and resources, and adapted to local needs.³ Indigenous household gardens are valuable because they adapt to so many different human needs and physical environments in such a great diversity of ways, and persist even after, or sometimes in spite of, the introduction of “modern” agriculture and gardens. In fact, indigenous gardens are not only widespread in the Third World, but are also popular in urban and rural areas of industrialized countries like the United States, Canada, Great Britain, and Poland where they have important economic, nutritional, and social functions.⁴

An approach to gardens in development based on indigenous gardens cannot use models because indigenous gardens are often unique to specific locations. Using an indigenous garden from one area as a model for gardens in another area can be as inappropriate as using any other garden model. New ideas are valuable and needed, but their appropriateness should never be assumed until tested and evaluated by gardeners themselves.

One reason for the lack of attention to indigenous gardens in development projects is that they are not well documented or understood in the horticulture, economic, nutrition, or social science literature that is the source of information for most project planners and field workers. European colonialism in the Third World did much to establish this bias against indigenous food production.⁵ Colonialism contributed to the belief still held by many today that indigenous food production expertise in the Third World is inferior and not suited to the modern world, and industrial, large-scale, capital- and resource-intensive agriculture is the only way to improve the situation.⁶

However, while development strategies like the “green revolution,” which are based on an industrial agriculture model, sometimes result in increased production, they have often led to increased inequities in the Third World countries where they have been applied. These strategies have frequently perpetuated dependence on the industrialized nations and the international markets they control.⁷ Meanwhile, malnutrition and poverty persist as major problems.

Indigenous gardens appear to have suffered from both the bias against indigenous agriculture, as well as from neglect because gardens were not considered to be a significant part of the food system. As a result, most of what has been written about indigenous gardens is brief and descriptive, and does not analyze the production techniques or the effects of gardens on income or nutrition. The assumption often follows that indigenous gardens are not based on scientific principles. Yet nothing could be further from the truth. In fact, the more that is learned about indigenous food production, the more obvious it is that it is based on the same principles as Western science. It is also obvious that both are influenced by the experiences and values of the people who practice them.

For example. Western agricultural science today is very much under the influence of a world economic system that emphasizes maximizing production and profits (section 3.2). The majority of research carried out is on strategies that increase farmer dependence on the market. Relatively little research is done on strategies that increase small farmer and gardener self-reliance or on minimizing destruction of the environment. The strong influence of values on the direction of research has led to a vicious cycle; because alternatives are not documented they are not believed to be valid, and those who might be interested are discouraged from researching and documenting them.⁸ Those who are practicing these alternatives, such as indigenous gardeners and farmers, are told that their skills and knowledge must be abandoned in favor of a system over which they have no control. However, the need for such alternatives is increasing, and nowhere is this more obvious than in the world’s drylands.

People in drylands - such as migrants to cities and to marginal rural areas, participants in large-scale irrigation schemes, and refugees fleeing across borders to temporary camps - are increasingly faced with new situations. Rising population densities, environmental degradation, water scarcity, and rapid social and cultural change mean new conditions for everyone. Without any outside encouragement, many of these people are growing gardens as part of their survival strategy. But the gardens they are familiar with may not be the most appropriate for their new, difficult conditions. These people do not need to be told how to garden, but they do need assistance as they work to develop gardens appropriate for these new circumstances.

While the problems of poverty and powerlessness facing the poor in drylands can only be eliminated by addressing their social and economic roots in colonialism, global inequity, and dependency, gardens can provide immediate benefits, and most importantly, can provide those benefits in a way that contributes to the solution of the larger problems.

References

¹ Durning 1990.

² Bittenbender 1985; Brownrigg 1985:100-112; Cleveland 1986; Cleveland and Soleri 1987; Niez 1987; Pacey 1978:23-24.

³ Dupriez and De Leener 1987; Sommers 1984; UNICEF 1985.

⁴ Crouch and Ward 1988; Gladwin and Butler 1984; Kleer and Wos 1988; Omohundro 1985.

⁵ Bodley 1990:13-14, Richards 1986:138-140.

⁶ For example, see Todaro 1985:285-310.

⁷ Latham 1990; for Mexico see DeWalt 1985.

⁸ Warren, et al. 1989.

Figure 2.1 Good Nutrition is Essential for Good Health

2. Gardens and nutrition in drylands

Nutrients are the chemical compounds that living plants and animals need for growth, physical maintenance, work, reproduction, and combating disease and other stresses. Nutrition is the study of the intake of food and the use of food nutrients by living organisms. Good nutrition is essential for good health (Figure 2.1). Malnutrition, the lack of required nutrients, is a major problem in drylands, especially for poor households. Malnourished people are more vulnerable to disease; at the same time, disease often contributes to malnutrition. People suffering from disease and malnutrition are not able to work as productively as healthy, well-nourished people. This increases dependence on outside help and reduces the quality of life (Figure 2.2). This can become a self-perpetuating cycle that affects a household, a community, and even a nation.

In this book we apply the concepts of nutrition to both plants and people. In Part II we discuss the nutritional needs of plants, sources of these nutrients, and the effects of nutrient deficiencies. In this chapter we consider the same issues for human nutrition in drylands. We include this chapter in a book on gardens because malnutrition is such a serious problem in drylands and because gardens can contribute a great deal to solving this problem. Gardens can do this directly by providing nutrients, or indirectly by increasing household income or savings which may be used to improve nutrition (Chapter 3). The nutritional effects of processing and preserving garden produce are discussed in Chapter 15 and the preparation of weaning foods from the garden in Chapter 16.

The relationship between food production and nutrition is very complex and improving human nutrition can be difficult. Human values and the assumptions and policies that are based on them have a tremendous effect on nutrition. Today there is growing recognition that assumptions about “development’’ and “progress” in diets, lifestyle, and agriculture that are modeled on Western, industrialized countries must be carefully reexamined.¹ Clearly, malnutrition is not simply a problem of inappropriate or inadequate food. It is also a consequence of policies and assumptions at the local, regional, national, and global levels that affect the production, processing, promotion, and distribution of food. Increasingly, malnutrition is a visible symptom of inequity, powerlessness, and greed. Both over-consumption by the world’s rich minority (Figure 2.3), and rapid population growth among the poor majority (frequently an individual or household response to these same problems), intensify the stress put on the finite natural resources on which we all rely.

2.1 Summary

Children, sick people, and pregnant and breast-feeding women need extra nutrients to avoid becoming malnourished. Those working hard in the home, field, or factory also need extra food. Food consumption and distribution is determined not only by need, but by beliefs and traditional dietary patterns, and by patterns of control over resources in the household, the community, the nation, and the world.

Energy, protein, vitamins A, C, D, folacin, thiamin, riboflavin, and niacin, and minerals such as iron, zinc, and calcium are nutrients essential for good health - however, they are often inadequate in dryland diets. Gardens are good sources for many of these nutrients.

Anti-nutrients are substances in food that are poisonous or that reduce nutritional value, and are present in all diets. Traditional processing techniques often help eliminate these.

Figure 2.2 The Cycle of Malnutrition, Disease, and Lower Food Production

2.2 Recommended dietary allowances and the nutrient content of foods

Recommended Dietary Allowances (RDAs) are nutritionists’ estimates of the amounts of nutrients required each day for the majority of healthy people in a given population to remain in good health.² These amounts include an increase over the average person’s needs to include healthy people whose requirements are greater than average.

The RDAs and tables listing the nutrient content of foods are often used together to estimate the nutritional adequacy of foods and diets, and to plan projects to increase the nutrient content of deficient diets. However, several points must be kept in mind when using RDAs:

· RDAs should be used for evaluation of populations, not individuals.

· Daily nutrient intakes can be averaged over a week.

· RDAs do not take into consideration unusual stress due to disease, strenuous work, climate, and previous malnutrition.

· There is much disagreement among the “experts” over the amount of some nutrients that is adequate.

Figure 2.3 Overconsumption by the Rich Threatens the Earth and the Future.

In most of the world’s drylands there has been very little work done to establish appropriate RDAs for local populations. The United States’ RDAs³ are often used, but they were calculated for an unusually affluent, inactive, and well-nourished population. RDAs established by the World Health Organization (WHO) may be more appropriate for most dryland areas.⁴ Using RDAs to estimate nutritional needs provides an overview of the nutritional situation and suggests areas that need further investigation. However, they should never be used to give quick and definitive answers about nutrition problems. In Table 2.1 we provide RDAs for some nutrients covered in this chapter.

Table 2.1 Recommended Daily Dietary Allowances of Major Garden Nutrients ^a

	Age (yrs)	Weight (kg)	Energyb (kcal)	Proteinc (gm)	Vit. A (RE)d	Vit. Ce (mg)	Iron (mg)
Children
	<1	7.3	820	14	300	30	5-10
	1-3	13.4	1,360	16	250	30-60	5-10
	4-6	20.2	1,830	20	300	30-60	5-10
	7-9	28.1	2,190	25	400	30-60	5-10
Males
	10-12	36.9	2,600	30	575	30-60	5-10
	13-15	51.3	2,900	37	725	30-60	9-18
	16-19	62.9	3,070	38	750	60	5-9
Females
	10-12	38.0	2,350	29	575	50	5-10
	13-15	49.9	2,490	31	725	50	12-24
	16-19	54.4	2,310	30	750	60	14-28
Adult man (moderately active: using 2,600-3,400 kcal/day)
		65.0	3,000	37	750	60	5-9
Adult woman (moderately active: using 2,000-2,400 kcal/day)
		55.0	2,200	29	750	60	14-28
Pregnant			+350	38	750	+10	28’
Breast-feeding			+550	46	1,200	+30-35	28’

^a Based on Passmore, et al. 1974.
^b Strenuous activity will increase requirements for energy.
^c Diets with plant foods as the main source of protein require higher intakes of protein.
^d RE = retinol equivalent; see section 2.6.1.
^e From NRC 1989:117-120.
^f From Latham 1979; Cameron and Hofvander 1983.

Tables listing the nutrient content of foods are estimates. As with the RDAs, they should be used with caution since the content of foods listed in these tables is based on samples and is affected by the following factors:

· The particular variety of the crop tested.
· Where and how the crops were grown.
· At what point in maturity the food was harvested.
· The time between harvesting and the time the analyses were conducted.
· Type of processing, if any.
· The combinations of foods analyzed.
· The technique used for the analyses.

Tables based on foods eaten locally are best, but these are not always available. The Food and Agriculture Organization (FAO) has published regional tables for Africa, the Near East, Latin America, and East Asia.⁵ The U.S. Department of Agriculture publishes a series of detailed volumes that are often used outside the United States.⁶ Table 2.2 gives examples of some garden foods rich in the nutrients we will discuss.

Table 2.2 Rich Garden Sources of Some Nutrients ^a

Nutrient	Garden sources	Example of nutrient/100 gm of edible portion
Energy	Sweet tree fruits, dried fruits and vegetables, nuts, seeds	Fresh tiger nutb 450 kcal/100 gm
Protein	Pulses, seeds, dried DGLVs*, especially for protein complementarity with staple	Dried sunflower seeds 23 gm/100 gm
Vitamin A	DGLVs, dark orange and yellow fruits and vegetables	Cooked amaranth leaves 277 REc/100 gm
Vitamin D	Exposure to sunlight	Depends on altitude, latitude, season, and skin pigmentation
Vitamin C	DGLVs, fruits	Fresh guava 183 mg/100 gm
Folacin	Fruit, DGLVs, pulses	Avocado 66 mcg/100 gm
Thiamin (B1)	Vegetables, fruits, seeds, nuts	Cooked cowpea leaves 0.3 mg/100 gm
Riboflavin (B2)	DGLVs	Cooked amaranth leaves 0.1 mg/100 gm
Niacin	Fruit, nuts, seeds	Banana 0.5 mg/100 gm
Iron	Dates, figs, nuts, seeds	Dates 1.2 mg/100 gm
Zinc	Seeds, DGLVs	Squash seeds 7.5 mg/100 gm
Calcium	DGLVs, dried fruits, pulses, sesame seeds	Dried cassava leavesd 313 mg/100 gm

^a Based on USDA 1982, 1984a, and 1984b, unless otherwise noted.
^b Irvine 1969.
^c RE = retinol equivalents; see section 2.6.1.
^d Leung, et al. 1968.
* DGLVs = dark green leafy vegetables.

2.3 Special nutritional needs in drylands

Table 2.3 summarizes the diet and health indicators of nutritional deficiencies in drylands. We will discuss them further in the sections on individual nutrients. In this section we cover the special needs of children, women, those doing heavy work, and sick people.

2.3.1 Children’s Special Needs

Because of the nutritional demands of growth and development, especially in younger children, adequate nutrition is essential to produce healthy and productive adults (Figure 2.4). For example, girls 1 to 3 years old need twice as much vitamin A and C per kg of body weight as adult women who are not pregnant or lactating. Children with protein-energy malnutrition and vitamin A deficiency are at great risk of becoming blind if they get measles, a common disease in much of the Third World (section 2.6.1). The daily requirement for energy in infants under 3 months is 120 kcal/kg of body weight, but drops steadily to 40-45 kcal/kg by age 207 The weaning period beginning at 6 months is critical; breast milk no longer provides enough nutrients, and nutritious weaning foods are often lacking (Chapter 16).

Table 2.3 Some Indicators of Nutritional Deficiencies in Drylands

Nutrient	Function	Dietary indicators	Health indicators
Calories	Energy for work, to maintain body, to fight sickness	Not enough to eat; lack of concentrated energy sources, especially for children	Children underweight for age; marasmus; adults unable to work long or hard
Protein	Growth and repair of body	Not enough to eat; lack of high protein foods like nuts, seeds, legumes	Children short for age, hair color lighter than usual; kwashiorkor
Vitamin A	Vision, bone growth, healthy skin, fighting infectious disease	Lack of DGLVs*, orange fruits or vegetables, and fat	Loss of night vision, can lead to blindness, xerophthalmia; increased infectious disease, malnutrition, death
Vitamin C	Iron absorption, development of skin, bones, and teeth	Lack of fresh fruits and vegetables or overcooking them	Scurvy: bleeding, slow wound healing, poor development of bones and teeth; anemia (see iron)
Iron (Fe)	Formation of blood	Lack of nuts, seeds, legumes, fresh fruits and vegetables	Anemia: tiredness, breathlessness, pale under eyelids and fingernails
Vitamin D and Calcium (Ca)	Development of bones and teeth especially in children	Lack of exposure to sunshine, diet high in phytic and oxalic acids	Rickets: softening and malformation of bones and teeth
Thiamin (B1)	Function of central nervous system	Diet of milled or polished grains, pulses, some root crops	Beriberi: weakness in legs, weight loss, marasmus in infants
Riboflavin (B2)	Use of energy and protein, tissue growth and repair	Lack of vegetables	Cracked, dry, itching skin, especially on face and genitals, failure to grow in children
Niacin	Metabolism	Diets based on maize or sorghum	Pellagra: dementia, dermatitis, diarrhea
Folacin	Production of red blood cells	Lack of DGLVs	Anemia (see iron)
Zinc (Zn)	Growth and repair of tissue	Lack of whole grains, pulses or animal products	Failure to grow, abnormal development of sexual organs, wounds slow to heal

*DGLVs = dark green leafy vegetables.

Child growth is an important sign of nutritional status. If children in the community go regularly to a health clinic they may have clinic cards with their growth plotted against standard growth curves. As with RDAs, most growth standards in use are based on better-nourished populations in the United States or Europe, and are inappropriate for judging individual children’s height or weight in the Third World. They are, however, a valuable tool in judging the growth pattern of a child or group of children. The pattern of growth for well-nourished children from all parts of the world is essentially the same, and a deviation from that pattern is a sign of malnutrition.

Figure 2.5 is a sample child growth chart similar to those used by child health clinics all over the world. The upper line on the chart shows the 50th percentile growth pattern in kilograms for boys based on WHO reference weights.⁸ That is, in the WHO sample, 50% of boys weigh more and 50% weigh less at those ages. The lower line is the third percentile for girls; 97% of girls weigh more, only 3% weigh less. The space between these two lines is called the “Road to Health” and it includes a wide range of possible weights for healthy children at different ages. But most importantly, the steady upward progress of the road to health outlines a healthy growth pattern. If a child’s growth fluctuates up and down within the road to health or drops below it, she is much more likely to become seriously ill, and her diet needs in-immediate improvement. The pattern in Figure 2.4 is very common in drylands and shows an overall lack of nutrients after weaning begins at approximately 6 months (A), and a seasonal drop in weight each year (B).

Figure 2.4 Children Need Good Nutrition to Grow, Work, and Play

Figure 2.5 A Sample Child Growth Chart (from Werner 1977)

2.3.2 Women’s Special Needs

Dryland diets often lack the extra nutrients needed by women during pregnancy, breast-feeding (lactation), and menstruation. Maternal malnutrition during pregnancy and breast-feeding can be harmful for the woman and may cause permanent physical and mental damage to the baby. Women who are malnourished during pregnancy are more likely to get sick and have low-birth-weight babies weighing less than 2.5 kg.⁹ These babies often grow slowly, have decreased mental ability, and are more likely to get sick and die than babies with higher birth weights.

In general, the amount of all nutrients in the diet should be increased during pregnancy and lactation because, in addition to meeting her own needs, the woman is contributing to the nutritional requirements of her baby. For example, vitamin A requirements increase 50-60% during breast-feeding,¹⁰ and requirements for vitamin C increase 15 % in pregnancy and 50-60% during breast-feeding.¹¹

Women may need as much as 150 kcal/day extra energy during the first 3 months of pregnancy, and 350 kcal/day extra during the last 6 months.¹² This is in addition to the 2,200 kcal/day required by a 55-kg woman who is moderately active. If the woman is doing heavy work during pregnancy, as many women in the Third World do (Figure 2.6), then her need for energy will increase ever. more. For example, hoeing requires about 3 kcal/min. more energy than that needed for moderate activity such as light work or walking. If the woman was hoeing for 4 full hours (4 × 60 min = 240 minutes) each day, she would need 720 kcal/day more (240 minutes × 3 kcal/min). Therefore, a woman who is 6 months pregnant and hoeing weeds for 4 hours a day would need about 3,270 kcal/day (2,200 + 720 + 350), or 50% more energy than usual. Breast-feeding also requires added energy, estimated to be at least an additional 550 kcal/day, especially during the first 6 months.¹³

Another nutrient important during pregnancy and lactation is calcium. In pregnancy extra calcium is needed for growth of the baby’s skeleton. Breast-feeding women lose approximately 245 to 280 mg of calcium each day.¹⁴ If these needs are not met in the diet, calcium is obtained from the mother’s bones in a process called demineralization, making her bones weaker and more susceptible to breaking. For this reason calcium intake should more than double, going from 400-500 mg/day for adult women to 1,000-1,200 mg/day during pregnancy and lactation. Because of the loss of blood during menstruation and childbirth, the iron RDA for women in their reproductive years (14-28 mg/day) is three times higher than that for men (5-9 mg/day).

2.3.3 Work

111 farming communities the labor demands of food production take priority over all others. However, many other important activities make demands on labor, for example, collecting water and fuel, child care, animal husbandry, gathering wild foods, craft production, house building, and repair. In urban areas wage labor and marketing may be the priorities.

The greatest demand for labor in many farming communities comes when staple food supplies from the previous harvest are low. This period is called the hungry season, and is common during the early rainy season in semiarid and subhumid drylands where the staple crops are rain-fed. This is the time when crops have to be planted and fields weeded. Without enough to eat people may be unable to do the necessary work, and so yields are low.¹⁵ People seen resting when there is work to be done may literally not have the energy to do it.

The time which Mossi men in Burkina Faso spend resting during the dry season may be necessary for them to recuperate from their strenuous agricultural work during the rainy season.¹⁶ Mossi women also work hard at farming during the wet season, but they do not have the benefit of a dry season rest period, since they must maintain the household and continue marketing and craft activities during that season.¹⁷ Although men expend more energy during the peak labor period, the fact that they may rest while women must continue working means that women may actually be more overworked.¹⁸ Although these people do not have dry season gardens, some nearby villages do. Neither women nor men would probably be interested in dry season gardens unless these gardens could eliminate the need for some current work by providing substantially more food or income.

Figure 2.6 In Many Places Pregnant and Lactating Women do Hard Physical Work

2.3.4 Illness

Illness increases the need for energy and other nutrients. For example, diarrhea reduces the absorption of nutrients and fever uses up extra energy. Any disease causing loss of blood such as schistosomiasis or hookworm increases the body’s need for iron. Therefore a sick person often needs special foods, and those recovering from an illness may also need extra food even after the symptoms are over. As already mentioned, it is important to care for these needs because malnutrition increases the effects of the illness.

The occurrence of many diseases in drylands varies according to the season. For example, the incidence of malaria increases dramatically in the rainy season when the number of mosquitoes increases. Gastrointestinal diseases may occur more frequently during the harvest or planting seasons because long work days often mean that food may be prepared early in the morning, long before being eaten later in the day. This delay allows disease-causing microorganisms to contaminate foods, making those who eat them sick.

2.4 Energy

Energy is needed for all of the body’s functions. People who are working hard, who are sick, or who are exposed to cold, need extra energy, as do growing children, and pregnant and lactating women. The prevalence of malnutrition among the poor in the Third World is due not only to hunger and poverty, but also to the fact that in comparison to the wealthy in the industrialized world they do more physical work, are sick more often and more severely, and frequently have inadequate clothing and housing.

In many dryland areas energy requirements vary seasonally with changes in the type and amount of work being done. For example, in central Burkina Faso Mossi farmers use the greatest amount of energy in the rainy season when most farm work is done.¹⁹ Men use approximately 2,410 kcal/day and women 2,320 kcal/day in the dry season. However, in the rainy season this increases to 3,460 kcal/day and 2,890 kcal/day, respectively.

Carbohydrates (CBHs) are the sugars and starches burned for energy in the body. Carbohydrates in the form of staple cereals or roots are the major source of energy in diets of the poor in drylands. Pats, from animal or plant products, are a very concentrated source of energy but are usually more expensive than carbohydrates and make up a relatively small proportion of most Third World diets. Protein will be used for energy only if the body does not have adequate amounts of other energy sources.

While dryland gardens will not be the main source of energy, they may supply energy in convenient forms and at times of the year when major sources are unavailable. This is especially important for weaning children, the group in the population most likely to become malnourished. For example, the caloric density of most fresh fruits and vegetables is only about one-sixth or less than that of grain, but this increases several times when they are dried. The energy content of some vegetables grown in household gardens such as tiger nut, and dried sweet potato, yam and cassava, and of many dried fruits, approaches or exceeds that of grains, which is about 350 kcal/100 gm.

2.5 Protein

Proteins are composed of amino acids, organic compounds of carbon, hydrogen, oxygen, and nitrogen atoms. The protein in food is broken down in the body into amino acids. The amino acids are then used to make the kind of proteins humans need to build skin, liver, brain, and all of the other tissues and organs, and to replace daily losses in sweat, feces, urine, skin, hair, and nails. Enzymes are made of proteins and play a vital role in chemical reactions like digestion, vision, movement, reproduction, and thinking.

The protein in the human body is made up of 22 different amino acids. If not present in the diet, most of these can be manufactured in the body from other amino acids. However, eight of them cannot, and must be contained in the diet. These are called the essential amino acids (EAAs) (Box 2.1). Infants require a ninth amino acid, histidine, which they receive in breast milk. It is also present in other animal milks and eggs.

In many Third World drylands, cereals (grains) are the staple foods, providing not only most of the calories, but most of the dietary protein as well. Therefore, diets that lack an adequate quantity of the staple food lead to protein-energy malnutrition (PEM, also referred to as PCM, protein-calorie malnutrition), a significant problem in many drylands.²⁰ A severe deficiency of food causes marasmus. People suffering from marasmus are extremely underweight; children with marasmus fail to grow because they are literally starving. Marasmus is common in weaned children, and also occurs in breast-feeding children who are not receiving enough breast milk or supplemental foods.²¹

Kwashiorkor is a form of PEM caused by a relatively greater lack of dietary protein than calories, and is especially common in weaning-age children.²² The growth rate of these children is slow and they have a swelling called oedema, which begins in the feet and legs, later spreading to the rest of the body. When the depression caused by pressing a finger oil the flesh above the ankle is slow to disappear it is a sign of oedema.

Box 2.1 Net Protein Utilization and Protein Complementarity Amino acids are not stored in the body, but are used soon after digestion for protein synthesis, that is, they are assembled in different ways to form various types of protein molecules. Amino acids not used for protein synthesis are excreted. Therefore, the most useful dietary protein is that which contains the EAAs in the same proportions as those required by human beings for protein synthesis. The use of protein in the diet is limited by that EAA which is most deficient compared with how much of it is required for protein synthesis. The value of all other EAAs present will be proportionally reduced (Figure 2.7). Net protein utilization (NPU) is the percentage of dietary protein in a food or a meal that can be absorbed and used by the body. For example, sesame seeds contain about 18% protein and have an NPU of 53 %.23 Thus 100 gm of sesame seeds would provide a person with 9.5 gm of usable protein (100 gm seeds × 0.18 =18 gm protein; 18 gm protein × 0.53 = 9.5 gm). Animals are more closely related to humans evolutionarily than plants are. Therefore animal proteins in eggs, meat, and dairy products have a higher NPU than most plant proteins. However, when plant proteins are eaten in the right combination the resulting NPU can easily equal that of animal protein24 because of protein complementarity. Protein complementarity means that the combination of foods in a meal compensates for shortages of specific EAAs in individual foods, making more protein available to the body. Through protein complementarity, fruits, vegetables, nuts, and seeds from the garden can increase the amount of protein available in the diet. For example, many dryland garden vegetables are high in the amino acid lysine but low in tryptophan, so combining them in meals with most cereals, which are low in lysine but high in tryptophan, increases the protein contribution of the garden.

Although the symptoms are not as obvious, mild or moderate PEM is far more common than the severe conditions of kwashiorkor or marasmus. For example, it is estimated that in the African Sahel 30% of the children between 1 and 2 years old suffer from moderate PEM.²⁵ The main signs of this condition are slow or no growth, loss of muscle tissue, a protruding belly, thin arms and legs, and sometimes a lighter than normal hair color. Children suffering from PEM are listless, weak, and unhappy. Protein-energy malnutrition also makes children more vulnerable to disease which, in turn, worsens their nutritional condition even further.

As with energy, gardens are not the main source of protein. However, they may supply protein in convenient forms and at times of the year when major sources are unavailable. Again this is especially important for weaning children. Dried seeds and pulses are often recognized as good protein sources, but other garden produce can also provide concentrated protein, especially when dried. For example, the dark green leaves of jute, cowpea, and pumpkin, widely eaten in Third World drylands, are only 4% or more protein by weight when fresh, but are 20% to 35% protein when dried.²⁶

While many nutrition programs have emphasized increased consumption of protein in the form of animal products, this strategy is not necessary for improved nutrition and can contribute to other health problems, as well as having serious negative social and environmental consequences.²⁷ Increased consumption of animal products is often associated with increased cardiovascular disease, obesity, and cancer. The social and environmental costs of increased consumption of animal products occur because the animals are fed large quantities of grains and pulses. For example, it has been estimated that 16 lbs of grain and soybeans are required to produce 1 lb of beef.²⁸ As this food is diverted from feeding people directly to producing meat and milk, less food is available to people, and it is produced at a higher cost. In many areas increased consumption of animal products is accompanied by an accentuated division between the small, affluent minority who are consuming those products and the vast majority whose diets are worsening, as in Mexico and Africa.²⁹ Not only are grains diverted from feeding people to feeding animals, but valuable land, soil, and water are invested in feed production as well. When grain production is not enough to meet the demands of the rich for animal products, grain is imported, using scarce foreign exchange.

Figure 2.7 Limiting Ammo Acids (from Lapp 1982:175)

2.6 Vitamins

Many fruits and vegetables from the garden are rich in vitamins, especially A and C. Vitamins are organic substances that occur naturally in plant and animal tissue. They are essential for the functioning of the body and must be contained in the food we eat because the human body cannot make them. An exception is vitamin D which is produced in the skin when it is exposed to sunlight. Fat-soluble vitamins (A, D, E, K) require fat in the diet to be absorbed by the body, and they can be stored in the fatty tissues of the body. Water-soluble vitamins (including vitamin C, folacin, thiamin, riboflavin, and niacin) are those that dissolve in water, so that any excess is excreted; foods containing them must be eaten more frequently. Here we discuss seven of the most important vitamins for dryland diets: A, C, D, folacin, thiamin, riboflavin and niacin. See Table 2.2 for examples of vitamin content of foods grown in dryland gardens.

2.6.1 Vitamin A

FUNCTION One of the most important functions of vitamin A, also called retinol, is in vision. A deficiency of this vitamin leads to a deterioration of the eyes, a disease known as xerophthalmia. Early signs include loss of vision in dim light (night blindness), while continued deficiency leads to blindness, especially in young children. Vitamin A is also necessary for bone growth and healthy skin, and vitamin A deficiency is associated with increased risk of sickness and death. Evidence from recent research strongly suggests that vitamin A deficiency increases the risk of death due to infectious diseases (such as measles, pneumonia, tuberculosis, dysentery, and gastrointestinal infections).³⁰ In turn, infectious disease and PEM may increase the risk of vitamin A deficiency.³¹ Vitamin A appears to be important for maintaining the tissues that protect the respiratory, stomach, and gastrointestinal systems, and the genital organs. A deficiency results in a breakdown of this protective barrier, leaving the body vulnerable to infection. This vitamin may also play a role in enhancing the body’s immune system.³² For these reasons vitamin A deficiency is seen as a serious threat to child health and survival and is becoming an important focus for efforts to improve children’s nutrition worldwide.

PROBLEMS IN DRYLANDS Vitamin A deficiency is one of the major nutritional deficiencies in the world. It often fluctuates seasonally, increasing when green vegetables and fresh fruits are not available. In India, for example, it is estimated that vitamin A deficiency contributes to 52,000 children becoming blind and 110,000 to 132,000 partially blind every year.³³ Vitamin A deficiency is probably high in most drylands, though there is not much detailed information for Africa or the Middle East. Some food surveys in the African Sahel suggest that in the dry season only 50% of vitamin A needs are met by the diet.³⁴ Deficiency can result not only from a lack of vitamin A in the diet, but from a low-fat diet, since vitamin A is a fat-soluble vitamin. Deficiency may also occur due to overall poor nutritional status, especially PEM, and due to infectious diseases, all of which reduce the body’s ability to absorb vitamin A.

REQUIREMENTS A daily intake of 750 mcg of retinol is suggested for adults and at least 300 mcg for young children. This means that just 30-100 gm (1-3 oz) of vitamin A-rich food can meet the RDAs for infants and children. Breast-feeding women who provide their infants with retinol in breast milk need approximately 1,200 mcg daily. Several months’ supply of vitamin A can be stored in the liver, so it is a good idea for people to eat lots of vitamin A-rich food when available, to make up for a shortage later on in the year. In savanna West Africa, for example, mangoes are rich in vitamin A and are often abundant at the end of the dry season. Children love mangoes and will devour lots of them if they get the chance.

SOURCES Fruits and vegetables contain provitamin A (carotenes, the precursors of the vitamin) primarily in the form of beta-carotene, which is transformed in the body into the active form of vitamin A, retinol (also called preformed vitamin A). Carotenes are substances with yellow/orange pigment which gives carrots, mangoes, sweet potatoes, loquats, and papayas their typical color. Dark green leafy vegetables, especially young leaves, are also rich in carotene, but the color is masked by the green of the chlorophyll. In general the darker orange or green the vegetable, the higher its carotene content. For example, there is much more carotene in dark green leaf amaranth than in light green head cabbage or lettuce. Nonindigenous fruits and vegetables with high prestige value often have lower vitamin A content than indigenous fruits and vegetables, leading to poor vitamin A nutrition as the former replace the latter. This is the case in northeast Brazil where apples, pears, oranges, and lemons are replacing local palm fruits, mangoes, passion fruit, and papayas in the local diet, contributing to vitamin A-deficiency in the region.³⁵ Some animal products such as eggs, butter, milk fat, and liver contain retinol, but these foods are often not available or are too expensive, except, perhaps, for people who herd their own animals.

Red palm oil is sometimes advocated as a source of vitamin A in drylands. Oil palms grow in the humid tropics, however, and buying imported oil is likely to be too expensive for poor dryland households. Sometimes vitamin A is added artificially to foods, such as biscuits, sugar, or monosodium glutamate (MSG, a traditional seasoning in Asia). However, their purchase may not only limit more important uses of household income, but these items may themselves be associated with increased health problems. Fortunately there are many rich sources of vitamin A that can be easily grown in household gardens.

Currently the standard practice is to give the vitamin A content of foods in retinol equivalents. However, some food composition tables still use international units (IU) of beta-carotene. To convert these to the retinol equivalents used in this book, the following equivalencies can be used:³⁶

1 retinol equivalent (RE) equals
= 1 mcg retinol
= 6 mcg beta-carotene
= 12 mcg other provitamin A carotenoids
= 3.33 IU vitamin A activity from retinol
= 10 IU vitamin A activity from beta-carotene.

2.6.2 Vitamin D

FUNCTION This fat-soluble vitamin is important for the regulation of calcium and phosphorus in the body to make strong bones and teeth, especially in infants and children (section 2.7.3). The ultraviolet rays in sunlight cause vitamin D to be formed from a naturally occurring substance in the skin. It is also present in certain foods. Rickets is a disease resulting from vitamin D deficiency and causes softening and malformation of the bones. PROBLEMS IN DRYLANDS In most dryland tropical and subtropical countries there is enough sunlight to supply people’s vitamin D requirements. However, there are vitamin D deficiencies in Ethiopia; in the larger, crowded cities of drylands in the Near East and Asia;³⁷ and where cultural or religious values stress covering most of the body, such as among some Moslems and Hindus.³⁸ Rickets may become a problem during and after weaning if the vitamin D present in breast milk is not replaced by exposure to the sun or supplied by another dietary source.

REQUIREMENTS The amount of sunlight needed to provide someone with their vitamin D requirement depends on the altitude (height above sea level) or latitude (how close to the equator) of where they live, the season, the frequency and length of exposure, and how dark their skin is.³⁹ People with darker skin colors must be exposed longer than those with lighter skin colors. The higher the altitude or the closer to the equator, the less exposure required. The elderly can only synthesize half as much vitamin D from sun exposure as a similar younger person can. It is difficult to set a dietary requirement since diet is not the only source of this nutrient. SOURCES Dryland gardens may contribute in two ways to meeting vitamin D requirements. They can provide eggs whose yolks are a good source. They can also provide a place of seclusion where, while doing other work, mothers can expose a portion of both their own and their baby’s skin to sunlight for a brief period every day. Unless fortified, cow’s milk is not a good source of this vitamin.

2.6.3 Vitamin C

FUNCTION Vitamin C (ascorbic acid) is a water-soluble vitamin needed for absorption of iron in the diet. This vitamin is also important for the formation and maintenance of the skin, bones, and teeth. PROBLEMS IN DRYLANDS Vitamin C deficiency is often associated with the iron deficiency anemia so prevalent in drylands (section 2.7.1). Lack of vitamin C also causes scurvy, characterized by bleeding, slow healing of wounds, and poor development of bones and teeth in children. Severe cases can cause death.

REQUIREMENTS Since vitamin C is constantly being lost from the body, a continual supply is needed in the diet. The following RDAs are for the United States and the requirements of Third World dryland populations may be greater. A daily intake of 60 mg/day for adults and 30 mg/day for children maintains an abundant quantity in the body.⁴⁰ but requirements for vitamin C increase during the infections and fevers common among children and adults of the drylands. Between infancy and adulthood the requirement increases from 30 to 60 mg/day. Pregnant women transfer vitamin C to their babies so they need about 10 mg/day more than the adult requirement. Breast milk is high in the vitamin and so lactating women need 30-35 mg/day more to compensate for this.

SOURCES Many dryland fruits and vegetables are excellent sources of vitamin C. Some examples are guavas (one of the richest sources with 326 mg/100 gm), tomatoes, citrus, papayas, chilis, sweet peppers, mangoes, and DGLVs like amaranth or baobab leaves (Figure 2.8).

2.6.4 Folacin

FUNCTION Folacin (also called folate and folic acid) is a water-soluble vitamin whose deficiency is the cause of the second most common type of nutritional anemia after iron deficiency anemia.⁴¹

PROBLEMS IN DRYLANDS Anemia due to folacin deficiency is especially common in pregnant women.

REQUIREMENTS Daily intakes of 100 mcg for children, 200 for adults, 400 for pregnant women, and 300 for breast-feeding women have been suggested.⁴² SOURCES Dark green leafy vegetables, fruit, yeast, and pulses (dried legume seeds, such as beans, which are cooked for eating) are good sources of folacin, as are kidney, liver, and cow’s milk.

2.6.5 Thiamin (B1)

FUNCTION Thiamin is necessary for functioning of the central nervous system. A deficiency in this water-soluble vitamin results in loss of reflexes and muscle control, especially in the legs. Beriberi is a disease of the nervous system which results from thiamin deficiency.

PROBLEMS IN DRYLANDS In cereals thiamine is found primarily in the germ and outer seed coat and so deficiencies of this vitamin occur where polished rice or other refined grain is the staple. Starchy roots (such as cassava) are also very low in thiamine and diets based on these roots can lead to deficiency.

REQUIREMENTS Only about six weeks supply of thiamin is maintained in the body. The daily adult intake suggested for thiamin is approximately 0.4 mg/1,000 kcal with increases of 0.1-0.2 mg/day more for pregnant and lactating women.⁴³ Because thiamin is essential for the metabolism of carbohydrates, diets that rely heavily on carbohydrates for energy require more of this nutrient; high-fat diets need less. SOURCES Thiamin is present in green vegetables and fruit, seeds, nuts, yeasts, pulses, and unrefined cereals. Fish, meat, and milk, including breast milk, are also sources of thiamin. Especially good dryland garden sources (per 100 gm edible portion) include cashew nuts (0.2 mg) and cooked, leafy cowpea vine tips (0.3 mg).

2.6.6 Riboflavin (B2)

FUNCTION Water-soluble riboflavin is necessary for chemical reactions in the body which synthesize protein, release energy from foods, and grow and repair body tissues. PROBLEMS IN DRYLANDS A deficiency of riboflavin causes lesions of the skin, especially the lips and corners of the mouth, and the tongue becomes a purplish red color. REQUIREMENTS Requirements for riboflavin are currently being reexamined. Based on extensive studies in China, some researchers are suggesting an RDA of 0.6 mg/day for adults, half the previously accepted RDA.⁴⁴ The research in China has not yet led to new RDAs for riboflavin during pregnancy and lactation. The current official RDA for the United States is an additional 0.3 mg/day during pregnancy and 0.5 mg/day during lactation.⁴⁵

SOURCES Riboflavin is found in dark green vegetables, yeast, milk and milk products, insects, eggs, fish, and meat. Riboflavin in pulses such as lentils and fava beans is increased by sprouting (section 15.5.1). Fermentation increases the riboflavin content of milk.

Figure 2.8 Green Leaves are a Good Source of Vitamin C

2.6.7 Niacin

FUNCTION Niacin is a water-soluble vitamin required by the body to metabolize carbohydrates, fats, and proteins. Without it many essential chemical reactions cannot occur. The body also creates niacin from the EAA tryptophan at the rate of 1 mg of niacin from 60 mg of dietary tryptophan. PROBLEMS IN DRYLANDS The disease resulting from a deficiency of niacin is called pellagra. Symptoms include skin lesions, changes in tongue color, diarrhea, and mental disturbances (the three Ds: dermatitis, diarrhea, dementia). Niacin deficiency is common in Africa,⁴⁶ especially where maize is the staple because the niacin in maize is unavailable to humans, and that grain is also low in tryptophan. Niacin deficiency can be avoided by supplementing maize-based diets with beans and other sources of tryptophan, as is often done traditionally. Niacin deficiency is also found in diets based on cassava tubers and may be associated with a staple diet of sorghum as this cereal is high in the amino acid leucine which can interfere with tryptophan and niacin metabolism.⁴⁷

REQUIREMENTS Approximately 5-15 mg of niacin/day is recommended for small children, 15-20 mg/day for adolescents and adults, and increases of 2 and 5 mg/day for pregnant and lactating women, respectively.⁴⁸ SOURCES Bananas, groundnuts, cowpeas, dried chilis, and sesame and sunflower seeds are all excellent sources of niacin. Another good source is yeast from beer brewing; in some countries of savanna West Africa yeast is often added to soups. Most pulses and cereals do not have a high niacin content, but where they are the staple they may supply most of the niacin in the diet. Insects and meat are also good sources of niacin.

2.7 Minerals

Like plants, people need mineral elements to stay alive. Seven elements account for 60-80% of the minerals in the body: sodium (Na), potassium (K), chlorine (Cl), sulfur (S), calcium (Ca), phosphorus (P), and magnesium (Mg).

In addition, eight other minerals, referred to as trace elements, are needed in very small (trace) amounts: iron (Fe), zinc (Zn), iodine (I), copper (Cu), manganese (Mn), chromium (Cr), selenium (Se), and molybdenum (Mb). We discuss only iron, zinc, and calcium because deficiencies of these minerals are the only ones common in drylands that can be easily addressed by household gardens.

2.7.1 Iron (Fe)

FUNCTION Iron is necessary for the formation of hemoglobin, a protein in red blood cells that carries oxygen from the lungs to all cells of the body. PROBLEMS IN DRYLANDS Iron deficiency anemia is a major health problem in drylands. This nutritional anemia is caused by dietary lack of available iron or of vitamin C. Vitamin C aids in iron absorption if eaten at the same time as foods containing iron. Signs of this anemia include tiredness, breathlessness, and pale skin (caused by lack of red blood) under the eyelids, inside of cheeks, and beneath fingernails. A spoon-shaped deformity of the nails on both hands may also be present. Vitamin C in the diet should be increased after any loss of blood, for example from hookworm, menstruation, and childbirth.

REQUIREMENTS⁴⁹ Depending upon diet and work, the RDAs for men and postmenopausal women are 5-9 mg/day and for young children, 5-10 mg/day. The higher requirements are for populations whose diets are primarily based on plant foods, as is common in the Third World. For women in their reproductive years, 14-28 mg of iron/day is suggested, the most being required during pregnancy and breast-feeding.

SOURCES There is a high iron content in many dryland garden crops including dates, figs, nuts, seeds, beans, and asparagus, as well as most DGLVs. However, only 5-10% of this iron is in a form that can be absorbed by humans. The iron in animal products is several times more absorbable than that in plant foods. Also, the iron content of plants depends on the iron content of the soil. Millet, wheat, yeast, and organ meats (e.g., liver, kidney) are good sources of this nutrient, although phytates in some cereals, nuts, and pulses lower iron absorption (section 2.10). Using iron utensils and cooking pots increases the amount of iron contained in the food.

2.7.2 Zinc (Zn)

FUNCTION Zinc is necessary for normal growth, sexual development, and reproduction. A deficiency leads to loss of appetite, failure to grow and to develop sexually, slow wound healing, decreased sense of taste, and changes in skin texture. PROBLEMS IN DRYLANDS Zinc deficiency is found in the Near East, especially Iran and Egypt. The availability of dietary zinc is reduced by binding with phytates and fiber,⁵⁰ which may be a problem with some dryland diets. REQUIREMENTS The RDA for the United States of 15 mg/day for men and 12 mg/day for women⁵¹ assumes regular consumption of animal products. Absorption of zinc in persons on largely vegetarian diets may be limited, due in part to phytates and fiber in the diet, and so the RDA may be higher. SOURCES Most seeds are high in zinc; for example, pumpkin seeds have 7 mg/100 gm. Zinc is also found in DGLVs, pulses, eggs, milk, seafood, and meat. The zinc content of plants (and of animal products formed from them) depends upon the zinc content of the soil.

2.7.3 Calcium (Ca)

FUNCTION Calcium is essential for the formation and repair of bones and teeth which contain 99% of the body’s calcium. In the blood stream this mineral is needed for the muscles and nerves and for coagulation of blood.⁵² PROBLEMS IN DRYLANDS Dryland diets high in phytates and oxalic acid may lead to calcium deficiencies (section 2.10). REQUIREMENTS Within limits, the body appears to adapt to varying intakes of calcium by adjusting the amount of the mineral excreted.⁵³ In addition, the more protein consumed the less efficient the body’s use of calcium, with large amounts excreted by individuals on high-protein diets. For this reason the RDA for calcium is higher for populations with high-protein diets, for example, children and adults in the United States (800 mg/day), as compared with the RDAs for populations whose diets contain less protein, for example, children (400-700 mg/day) and adults (400-500 mg/day) in Africa.⁵⁴ SOURCES DGLVs, some pulses, hulled sesame seeds, yeast, and dairy products are all sources of calcium.

2.8 Fats

Dietary fats can be either solid like butter or lard or liquid like groundnut oil. They provide twice as much energy per volume as protein or carbohydrates, and are therefore good additions to weaning foods (section 16.3.1). Fat in the diet is needed to digest the fat-soluble vitamins A, D, E, and K. Fats contain fatty acids, some of which are essential for the human body.⁵⁵ Plant oils like those found in avocados, olives, groundnuts, and seeds such as sesame and melon are a good source of fatty acids. In the body, fat is the storage tissue formed when more energy is consumed than is immediately needed.

2.9 Fiber

Dietary fiber such as cellulose is an indigestible carbohydrate, or carbohydrate-like substance in plant food. Fruits, vegetables, and pulses from the garden are sources of fiber, as are unrefined grains. Fiber is important for the movement of food through the intestine. It encourages the growth of beneficial bacteria there and helps prevent some diseases in the digestive and excretory systems. The kind of fiber in fruit, vegetables, and pulses also helps reduce cholesterol levels.

Cholesterol is a waxy substance in the blood essential for body functioning - but too much of it clogs the arteries causing heart disease, a major problem in the industrial world and some areas of the Third World.

Too much fiber in the diet, however, can reduce absorption of many minerals because the food is moving too quickly through the body. This is especially important in the diets of young children. Some of the processing and preparation methods discussed in section 16.3, such as removing bean “skins,” help reduce fiber content of garden produce used in weaning foods.

2.10 Anti-Nutritients

Anti-nutritional factors, or anti-nutrients, are substances found in most foods, and that are poisonous or in some way limit the nutrients available to the body. Plants have evolved these chemicals to protect themselves from being eaten.⁵⁶ Frequently the anti-nutrients occur in such small quantities that they cause no harm. But if the diet is not varied some of these toxins can build up in the body to harmful levels. In many areas traditional food processing techniques effectively eliminate any harmful effects of anti-nutrients occurring in the diet. The anti-nutrients discussed below are summarized in Table 2.4.

Some of the most common anti-nutritients found in dryland garden foods are those that form insoluble salts with minerals like calcium and iron, reducing absorption of these minerals by the body. Phytates occur in cereals, pulses, and nuts. People consuming foods high in phytates may develop symptoms of calcium deficiency, especially in areas or seasons where calcium intake is low. Phytates also appear to decrease iron and zinc absorption.⁵⁷ To reduce phytate content one may soak pulses and discard the water or sprout them.⁵⁸ The slow fermentation process used to leaven many traditional grain breads also reduces phytates. The longer the fermentation the fewer the anti-nutrients that remain in the bread.

Relatively large amounts of oxalates are found in some DGLVs like leaf amaranths and onion greens, as well as in purslane and in members of the chenopod family such as spinach and chard. A diet high in oxalates can cause calcium deficiency and could eventually lead to kidney damage.⁵⁹ Boiling or steaming these vegetables and then rinsing them and discarding the water reduces their oxalate content. Sesame seed hulls contain oxalates and should be removed to make the calcium in the seed available.

Table 2.4 Anti-Nutrients Common in Dryland Diets

Anti-nutrient and source	Effect	Ways to minimize
Phytates: cereals, pulses, nuts	Reduce Ca and Fe absorption	Soak (discard water), and sprout cereal before cooking, slow fermentation of bread doughs
Oxalates: DGLVs, sesame seed coats, fruit	Reduce Ca absorption, encourage formation of kidney stones	Steam or boil greens, rinse and discard the water, hull sesame seeds, eat fruit soon after harvest
Tannins: dark-colored pulses, sorghum.	Reduce digestion of proteins and CBHs	Soak (discard water), sprout and cook, remove dark seed coats
Oligosaccharides: pulses	Intestinal gas, discomfort, loss of appetite	Sprout, ferment, cook thoroughly
Hydrogen cyanide (HCN): crucifers, sorghum sprouts, cassava, cashews, groundnuts	Contribute to goiter if diet is low in iodine	Varied diet, more iodine consumption, cook sorghum sprouts, ferment cassava, eat crucifers that are young because age increases HCN content
Aflatoxin: many pulses, nuts, and seeds	Liver damage, cancer	Dry, cool storage conditions, do not store damaged pulses, nuts, or seeds

Some vitamins in food may be destroyed by anti-nutritional substances. Ascorbase is an enzyme released by plant cells in response to damage such as harvesting.⁶⁰ This enzyme starts a reaction eventually changing ascorbic acid to oxalic acid, an oxalate. The ascorbase content of fruits and vegetables varies both between species and varieties. Because this reaction increases during storage, especially in warm conditions, it is best to harvest most garden produce as close as possible to the time when it will be eaten (section 15.2).

Tannins are substances in food that reduce digestion of proteins and carbohydrates. The foods from dryland gardens highest in tannins are pulses, especially their seed coats. Tannins have a dark color; pulses with light-colored seed coats contain a negligible amount of tannins. Removing the seed coat, as is traditionally done when making dhal in India, removes 83-97% of the tannins in pulses.⁶¹ Simple practices, already used in the preparation of pulses in many areas, such as soaking and discarding the soaking water, germination, and cooking are all ways to remove tannins. Sorghum can also contain significant amounts of tannins. In southern Africa where a variety of drought-resistant sorghum with a high tannin content is eaten it is associated with an unusually high incidence of cancer of the esophagus.⁶²

Other anti-nutritional factors found most often in pulses are oligosaccharides which increase the formation of intestinal gas, often causing discomfort and loss of appetite. Sprouting, fermentation, and thorough cooking reduce oligosaccharides.⁶³

Some foods contain substances that react to form the poison hydrogen cyanide (HCN) either during processing or digestion. Where diets are low in iodine, HCN is a cause of a disease of the thyroid gland called goiter. Sources of HCN in dryland diets are cashew nuts, groundnuts, and many vegetables in the crucifer family. For people not suffering from goiter, consuming these foods as part of a varied diet is not a problem. Sorghum sprouts and cassava are high in HCN. However, if the sprouts are cooked or malted and the cassava is fermented, both traditional practices in West Africa, the HCN content is reduced to safe levels.⁶⁴ Lima beans are also high in cyanides and should not be eaten raw. Lima beans should be presoaked, drained, boiled, and drained again to rid them of most of this toxin.

Some molds growing on crops (section 13.3.4) and foods produce poisons called mycotoxins. The mycotoxin aflatoxin is found in molding dryland garden foods such as groundnuts and other pulses, nuts, and seeds. If eaten, it can cause severe and sometimes deadly liver damage. Aflatoxin-producing molds grow under warm, moist conditions, and so care must be taken when storing these foods during the rainy season. Damaged and broken pulses are especially vulnerable, and any that look discolored, are moldy, or have a bad smell should be composted, not eaten. They should not be fed to animals as they too can be poisoned and the toxin can be passed on to people through meat and milk.⁶⁵

2.11 The effects of gardens on nutrition

The nutritional effect of gardens has seldom been measured, partly because it is so difficult to do. However/gardens can make a significant contribution to solving three of the most important dryland nutritional problems: PEM of infants and children, vitamin A deficiency, and anemia resulting from lack of iron and vitamin C.⁶⁶

Even when working with gardens on the community and household level, the path between food production and nutrition is complex. Availability and access to land, good soil, water, and seeds or cuttings determine whether food can be produced. When gardens can be grown their influence on the nutritional status of household members depends on many factors including:

· The amount of different foods harvested from the garden during each season of the year.
· The quantity and quality of the nutrients in garden produce.
· The availability of nutrients in garden produce.
· Methods of storage and processing.
· Distribution of garden produce to different members of the household.
· The amount of produce not consumed by the household, e.g., because it is sold.
· The way that food from the garden is combined in meals with other foods.
· The health and activities of household members.

For example, an assessment may find that children in households with gardens are just as deficient in vitamin A as children in households without gardens. The gardens are not providing the children with the benefits they need. In surveys in Indonesia, for example, it was found that 80% of families with children who had a vitamin A-deficiency-caused eye disease consumed DGLVs once a day, and 99% once a week, the same frequency as families of children without the vitamin A deficiency disease.⁶⁷ To understand the potential contribution of gardens to improving vitamin A nutrition in this case, we would need to know what causes the difference in the vitamin A nutrition of children in families who consume similar amounts of DGLVs. Is there a difference in the distribution of DGLVs in these families? Are foods prepared differently? Are children’s eating habits different?

Many of the dryland garden crops that are excellent sources of energy, protein, vitamins, minerals, fats, and fiber have been presented in sections 2.4 to 2.9. In the following sections we discuss the nutrient yields of gardens and the contribution of gardens to nutrition.

2.11.1 Nutrient Yields from Gardens

The nutrients produced in indigenous Third World gardens have rarely been studied, but data from other types of gardens is available. Research on two urban desert gardens (77.4 and 58.3 m², 833 and 627 ft²) in Arizona, USA, recorded a year-round harvest that provided the gardeners with significant proportions of the RDAs for 10 nutrients, including over 50% of the RDA for vitamins A and C for more than half the months of the year. Only 2 to 3 hours per week were spent gardening.⁶⁸ Perhaps the most ambitious study to date was carried out in experimental gardens in the humid tropics by the Asian Vegetable Research and Development Center (AVRDC) in Taiwan.⁶⁹ Results from the third year of the study (1983-84) showed yearly production of RDAs for a family of five, determined quarterly on samples from the gardens, as follows: 13-18% protein, 33-42% calcium, 56-82% iron, 82-125% vitamin A, and 336-374% vitamin C.

2.11.2 Effects on Nutrition

The ways in which the abundant nutrients potentially available from household gardens are actually translated into improved nutritional status depend not only on the place of garden foods in the diet, but on the complex social dynamics of households, which determine who receives which foods at what times. Working males, for example, may be the first to eat, then older women, and finally younger women and their children. This is sometimes due to women’s weaker bargaining power in the household, or to their low social, economic, and cultural status outside of the household. One study in the Philippines showed that this can result in inadequate consumption of calories by women as compared with men.⁷⁰

Having more household food may result in more reaching the last in line. When women control the garden and its produce, household food distribution may also change for the better nutrition of children, especially during weaning.⁷¹ Yet it can never be assumed that women’s gardens will automatically have this benefit, since there is very little evidence on how frequently it occurs, or what conditions favor it. Therefore, garden projects promoting women’s gardens for improving nutrition of women and children must be based on an understanding of how household dynamics affect food distribution and use of income in particular communities.

The combination of foods in various household meals can have a great effect on the total nutritional value of the diet. In theory, gardens facilitate the continual consumption of small amounts of a variety of nutrients which complement the rest of the diet.⁷² For example, the essential amino acid patterns ill the protein of vegetables complement those of many grains, seeds, and nuts (section 2.5). In addition, eating fresh produce from the garden soon after harvesting avoids the postharvest nutrient losses that occur due to storage, handling, exposure, and processing.

Most of the research on gardens, food consumption, and household nutritional status is from humid areas. For example, in Tabasco, Mexico, it was found that fruits and vegetables were not eaten unless they were grown in the family garden because they were otherwise too expensive to purchase.⁷³ A study in Java found that low-income households consumed the least amount of rice, but the greatest amount of leafy garden vegetables high in vitamin A, and that gardens provided up to 40% of the household requirement for energy.⁷⁴ In Puerto Rico, “homemakers” were more likely to have diets adequate in vitamins A and C, and preschoolers in vitamins A, C, and riboflavin, and calcium, energy, and protein, when their households produced fruit and vegetables for consumption in home gardens.⁷⁵

In southern India it was found that garden production was positively correlated with the nutritional status of weaning age children.⁷⁶ This was especially true in the slack season for off-farm employment when garden produce, or the income from selling it, kept child nutritional status from falling. A garden project in the Philippines found gardens were positively associated with higher levels of vitamin A in children who had the lowest levels before the project, and with a significant increase in weight for height of children.⁷⁷

Nutrition education can be a vital part of garden programs aimed at improving nutrition, especially when gardens are being introduced for the first time, or when new types of garden crops become available. A garden project in Ilesha State, Nigeria, in the late 1960s emphasized traditional crops and gardens and included a strong nutritional education component directed at local women.⁷⁸ This project is said to have reduced child death due to malnutrition among gardening households from 10% to 6% in three years. However, research on the nutritional impact of a garden project 20 years after its initiation in Senegal shows no improvements among participating households.⁷⁹ The researchers believe this is due to lack of nutrition education and because most of the produce was being sold with only a small percentage of that income used directly for food purchases.

Nutrition education is also vital to counter the increasing consumption of prestige foods associated with a “modern” way of life, many of which are not as nutritious as indigenous local foods. For example, in northeast Brazil where there is vitamin A malnutrition, nutrition education may be necessary to counter the replacement of local fruits and vegetables high in vitamin A with fruits and vegetables imported from the south. These imports are more popular because of their association with the more “modern,” affluent section of the country.⁸⁰

It is obvious that there are many links between the garden and improved nutritional status. Problems can occur with any one of the links which will decrease the nutritional contribution of the garden. However, some ways to improve the chances that gardens will succeed in having a long-lasting, positive effect on people’s overall nutritional status are to:

· Base new or improved gardens on indigenous gardens and indigenous crops.

· Encourage gardeners to grow and eat a wide variety of foods.

· Support or introduce simple harvesting and processing techniques that preserve the nutritional quality of garden foods.

· Recognize and address intra-household differences in consumption.

· Include participatory nutrition education at all stages of the work.

2.12 Resources

The best source of information for those working to improve nutrition is the diet of healthy people in the community. Secondary school or college nutrition textbooks are good references for learning the physiology of human nutrition. Detailed information on the RDAs can be found in NRC (1989), FAO (1973), and Passmore, Nicol, and Rao (1974).

Diet for a Small Planet (Lapp 1982) is a good exploration of the social, economic, environmental, and nutritional impacts of protein in the diet.

One of the best practical books on nutrition for field workers is Human Nutrition in Tropical Africa by Latham (1979). Although written from the author’s experience in East Africa, the combination of simple theory and practical information give this book a wider audience.

“What to Eat to be Healthy,” Chapter 11 in Where There is No Doctor (Werner 1977), discusses nutrition and health. The Manual on feeding Infants and Young Children (Cameron and Hofvander 1983) focuses on infants’ and children’s special nutritional needs. Brownrigg (1985) includes some case histories and discussion about garden projects and nutrition.

References

¹ Latham 1990.

² NRC 1989:10-12.

³ NRC 1989.

⁴ Passmore, et al. 1974.

⁵ Leung, et al. 1968; FAO 1982a; Leung and Flores 1961; Leung, et al. 1972, respectively.

⁶ For gardens see USDA 1982,1984a, 1984b, 1989.

⁷ Cameron and Hofvander 1983:38-39.

⁸ Cameron and Hofvander 1983:11.

⁹ Cameron and