T. Johns and P. Maundu
Timothy Johns is in the School of Dietetics and Human Nutrition, Macdonald Campus, McGill University, Ste Anne de Bellevue, Quebec, Canada, and the International Plant Genetic Resources Institute (IPGRI) Regional Office for Sub-Saharan Africa, Nairobi, Kenya.
Patrick Maundu is also with the IPGRI Regional Office for Sub-Saharan Africa in Nairobi.
Diversity in production systems and natural ecosystems strengthens
the
opportunities for diversity in diets and the prospect of a sustainable future.
Forest ecosystems contribute to the diets and subsistence of forest dwellers, and in increasingly market-oriented economies they provide a significant portion of the food and medicines consumed by urban populations. Recognition that the sustainable use of forest resources is essential for local livelihoods and the well-being of national populations provides a foundation for investment in conservation of forest biodiversity and its integration with objectives of poverty reduction, food security and disease reduction in development policies. However, it is first necessary to demonstrate more fully that biodiversity is indispensable for combating malnutrition and diseases of vulnerable populations in a global context of unprecedented population growth and resource demand. This article outlines key components of the link between forest biodiversity and the viability of contemporary food systems.
Some neotropical fruits in Brazil that are excellent sources of provitamin A
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Most societies recognize that food, medicine and health are interrelated. Food is typically associated with cultural identity and social well-being. Indigenous peoples’ foods form part of rich knowledge systems. Traditional food systems typically draw on local biodiversity and are based on local production and management of land and specific environments (Johns, 2006).
Ethnobiological literature documents the historical and current importance of an array of resources consumed by communities living in and around the world’s forests. It also demonstrates the richness of the traditional knowledge of indigenous and local communities related to the gathering and hunting of plant and animal foods and the medicinal value of forest species. From a wide range of ecosystems, some 7 000 of the earth’s plant species have been documented as gathered or grown for food (Wood et al., 2005), and thousands more have medicinal properties (Napralert, 2006).
From a nutritional perspective, forest environments offer ample sources of animal (vertebrate and invertebrate) protein and fat, complemented by plant-derived carbohydrates from fruits and tubers and diverse options for obtaining a balance of essential vitamins and minerals from leafy vegetables, fruits, nuts and other plant parts. Although many forest types have scant wild sources of carbohydrate, this lack can be overcome through forest-based agricultural production of cereals (e.g. maize), roots and tubers (e.g. cassava and yams) or bananas. Similarly, traditional cultivation systems drawing on agrobiodiversity can make adequate food available in spite of potential intermittent and seasonal shortages of many forest foods. Thus forest food resources can provide a valuable safety net in case of shortage of food crops. Undoubtedly, then, forest biodiversity is the basis for nutritional sufficiency for some populations. Some forest products, such as the fruits of Mauritia vinifera and other Brazilian palms that are rich in provitamin A (beta-carotene and other carotenoids), are recognized as exceptional nutrient sources (Rodriguez-Amaya, 1996, 1999) (see Table). However, the nutrient composition of most wild species and minor crops has been poorly studied (Burlingame, 2000).
Links between food and health are increasingly understood in terms of the functional benefits provided by phytochemicals, including numerous carotenoids and phenolics, apart from their value as essential nutrients (Johns and Sthapit, 2004). Stimulants of immunity and antioxidant, glycaemic and lipidaemic agents can moderate communicable and non-communicable diseases such as diabetes, cancer and cardiovascular disease. Guava, for example, is rich in the antioxidant lycopene, which has recognized anti-cancer properties. Many nuts have a high content of specific oils such as omega-3 fatty acids (walnut) and mono-unsaturated fatty acids (almond, macadamia, pistachio, hazelnut) which reduce the risk of cardiovascular and other diseases. Argan nuts (Argania spinosa) from the southwestern part of Morocco offer similar benefits, but many forest species with commercial potential have not been characterized for their specific fatty acid composition (Leakey, 1999). Leaves of many forest species are rich sources of xanthophylls which contribute to optimal eye function. Examples include leaves of Gnetum spp.and Adansonia digitata (baobab), which are widely eaten in sub-Saharan Africa, and Cnidoscolus acontifolius, which is locally important as a vegetable in Central America (Serrano, Goñi and Saura-Calixto, 2005).
While these kinds of functional properties of foods are seldom recognized by local communities without the benefit of scientific analyses, people often attribute to particular foods value in treating or preventing disease. Indeed the distinction between food and medicine which characterizes scientific perspectives stands in contrast with traditional concepts of health which recognize the therapeutic and sustaining values of food more holistically.
The widespread use of roots, barks and other forest plant parts as medicine appears to offer public health benefits, but these are difficult to validate scientifically. Ethnobotanical studies in tropical forest areas typically document knowledge of hundreds of species within local communities and widespread use of plants in primary health care. Much of the recorded data on the use of medicinal plants is anecdotal and idiosyncratic, and their specific contribution to the health of individuals cannot be effectively evaluated without controlled investigations. Ethnopharmacological research, including clinical studies, demonstrates the efficacy of many traditional remedies while failing to substantiate the pharmacological value of many others. Long-term epidemiological studies would be needed to confirm the contribution of specific remedies, phytomedicines or foods to the health of populations. Even these remain inadequate to measure the efficacy and contributions of traditional healing practices to physical and mental health.
Nonetheless, for forest-based societies that draw on traditional knowledge for most of their subsistence needs, the use of a diversity of resources can be expected to contribute to health. Although many traditional subsistence systems depend on one or more staples such as cassava, sago, rice or maize, such diets are kept diverse and balanced through small but complementary amounts of animal-source foods including birds, fish, insects and molluscs, as well as sauces, condiments, snacks and beverages obtained from plants.
| Leaves of Cnidoscolus acontifolius, an excellent source of beta-carotene (provitamin A) and lutein, make important contributions to diets of forest dwellers in southern Mexico, Guatemala and neighbouring countries |
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T. Johns |
| Even small amounts of animal-source foods, including insects, complement staple foods and keep traditional diets diverse and balanced (roasted termites on sale in Limbe market, Malawi) |
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P. Maundu |
Changes in developing-country food systems affect both human health and the health of ecosystems. When rural populations lose access to important natural resources because of environmental degradation, economic changes (including changes in land use), cultural erosion or poverty, their reduced diet results in food insecurity, malnutrition and disease. Similarly, when people move to cities they lose ready access to the beneficial products of local biodiversity because these are either unavailable or unaffordable.
Urbanization, in conjunction with the commercialization of the food supply and other subsistence items, results in considerable changes in patterns of consumption and resource use. In Latin America 78 percent of people live in cities. Forty percent of Asians and Africans are urban, and in both regions this figure is expected to rise to 50 percent by 2025 (United Nations, 2004). With the global population expected to grow to 8.3 billion by 2030, this elevated urbanization rate represents a tremendous increase in the number of humans who depend on foods that are purchased and produced by others outside cities. Simply meeting present and future food security needs necessitates intensification of production systems of cereals, sugar, oilseeds, other staple crops and animal-source foods. Production increases will draw heavily on technology and greater exploitation of land and natural ecosystems, including forests.
Three crops alone – rice, wheat and maize – already provide over 50 percent of the global human food supply (Wood et al., 2005). Along with rice and wheat, a couple of other products of high-input, high-yield agriculture, sugar and edible oil (soy and other), are important commodities in global trade. Together these staples form the bulk of the diet of urban dwellers in Africa, Latin America and Asia. Large-scale commercial agriculture responds to the demand for these crops for export and local markets. On the other hand, the food supply of urban dwellers in many developing countries increasingly depends on food imports.
The availability of calorie-rich food at affordable prices contributes to food security and has reduced the number of undernourished people. However, for poor people whose food choices are determined foremost by economic means, dietary options are limited. At the same time local producers, particularly small-scale farmers, have difficulty competing with inexpensive (often subsidized) imports. Deficiencies in infrastructure and support for small-scale production contribute to keeping local forest products unavailable or expensive in local markets. As supermarkets take a larger market share in developing countries, opportunities for local producers to sell diverse products, particularly wild foods from forests, may be reduced (Reardon et al., 2003). However, although it is difficult to compete, local producers need not be excluded, especially if they can highlight the unique nature of their products and fill speciality niches.
In many areas, as use of local biodiversity decreases, a diet that is reduced in variation but high in calories contributes to increasing problems of obesity and non-communicable disease (Popkin, 2002). The globalization of culture and commerce fosters a westernization of developing country food systems and diets. Where high rates of infectious illness persist and undernutrition and overnutrition co-exist, communicable and non-communicable diseases create a double burden. Chronic diseases pose a staggering cost, particularly for developing countries and economies in transition. A recent report by the World Health Organization (WHO, 2005) estimated that the loss in national income as a result of heart disease, stroke and diabetes over the next ten years for populous countries such as China, India and the Russian Federation will be in the hundreds of billions of United States dollars each, while other developing economies such as Brazil, Nigeria, Pakistan and the United Republic of Tanzania will lose US$49.2 billion, $7.6 billion, $30.7 billion and $2.5 billion, respectively. The challenge is to address a problem whose causes and consequences span health, agriculture, culture, markets and environment.
While the impacts of rapid sociocultural changes can be seen throughout the world, those countries that retain strong traditional food systems in which diet has recognized health, cultural and ecological roles are better able to avoid the concomitant increases in disease. Asian and Mediterranean diets provide the clearest examples (Kim, Moon and Popkin, 2000; Trichopoulou and Vasilopoulou, 2000).
Important lessons on linking traditional sources of food and dietary diversity to rural and urban health are emerging from research and promotional activities led by the International Plant Genetic Resources Institute (IPGRI) in sub-Saharan Africa and other regions (Frison et al., 2005). In East Africa, for example, the link between traditional food culture and health is related to an attachment to rural and ethnic origins coupled with social and spiritual values. In a recent cross-sectional survey in Nairobi, Kenya, ethnic identity was found to be the main determinant of patterns of traditional food consumption, more important than economic status (Johns et al., 2005). In other regions, connections among sociocultural, health and environmental factors take other forms. In the Republic of Korea, social marketing draws on cultural traditions to link healthy cuisine with concern for rural producers and production systems (Kim, Moon and Popkin, 2000). Brazil has undertaken a multisectoral initiative to mobilize the biological resources of its Amazonian and other forests to address national health needs. The Slow Food Movement, with origins in Italy and growing influence in Europe, North America and elsewhere, aims to link producers and consumers of excellent quality foods, to protect traditional foods at risk of extinction and to conserve biodiversity in the food supply, further illustrating the connection of sociocultural values to human and ecosystem health (Petrini, 2004).
Market and economic factors act as powerful determinants of the transformation of food systems. Consumer demand for forest-derived foods and medicines ensures their continued
presence in markets as long as supply is affordable and sustainable.
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Traditional concepts of health tend to view the therapeutic and sustaining values of food more holistically; for example, the nutritious roots of Mondia whitei (white ginger), an African woody climber, lends flavour to foods and tea while also serving a variety of medicinal purposes (street vendor in Kenya) |
P. Maundu |
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Although the spread of supermarkets may reduce opportunities for local producers, consumer demand for forest-derived foods and medicines ensures their continued presence in markets (sale of Uapaca kirkiana fruits in Mutare town market, Eastern Zimbabwe) |
P. Maundu |
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Most of the world’s poorest households are in countries harbouring the largest amounts of biodiversity, much of it in and associated with tropical forests. As a consequence, conservation and poverty cannot be addressed independently. Since most of the world’s population today depends at least in part on purchased foods, improving accessibility to a range of unprocessed and processed forest products offers nutritional benefits to the rural and urban poor. This can be best achieved within a model linking local producers and consumers in which biodiversity contributes to poverty reduction and viable economies within a supportive sociocultural context. The model draws on recognized and potential synergies among biodiversity conservation, income improvement, sociocultural values and health outcomes (see Figure). For example, while direct use of plant and animal resources coupled with income generation and integrity of sociocultural traditions can contribute to better nutrition and health, a healthy population is conversely more likely to have the incentive and resources to better manage its natural environment. Local communities can manage and use gathered and cultivated species to improve their livelihoods by developing products that can be marketed to meet demands of local food cultures and offer nutritional and cultural benefits to (increasingly urban) consumers. Thus, linking biodiversity and health is both a response to the consequences of economic growth and a way to direct growth in a positive manner.
Promotion of dietary diversity at the local, national and regional levels is a priority and can include the transfer and sharing of information and successful experiences in defending and enhancing the dietary use of plant and animal diversity.
Consumption of more diverse foods by urban dwellers depends on the affordability and accessibility of a range of products from the wild. Nonetheless, experience indicates that urban consumers will pay high prices for speciality foods if they consider them to be of high quality and/or desirable from a cultural perspective. Viable markets depend on demand from consumers which can be driven through availability, education and promotion and by reinforcing traditional food culture (Kim, Moon and Popkin, 2000). Demand translates into opportunities for income generation and improved livelihoods when rural farmers are linked with consumers. Reduction in poverty has a crucial indirect impact on health. Greater diversity within production systems and natural ecosystems strengthens the opportunities for resource sustainability and for diversity in all diets.
In practice, contemporary food systems exist within an increasingly commercial context. In developing countries, supermarkets and other commercial entities are desirable partners in any effort to combine economic and social rationales in support of traditional use of biodiversity in food. For example, in Nairobi, Kenya, a local non-governmental organization called Family Concerns successfully promoted African leafy vegetables by linking small-scale producers with a supermarket chain (Johns et al., 2005).
International policies and regulations related to trade and to human rights, including cultural and food rights, must ensure the viability of food systems that guarantee the sustainability of local ecosystems and respect cultural traditions. The international voluntary guidelines on the right to food (FAO, 2005), for example, explicitly recognize the importance of customs and traditions on
matters related to food. The rationale for the Cross-Cutting Initiative on Biodiversity for Food and Nutrition of the Convention on Biological Diversity (CBD, 2006) acknowledges that “traditional food systems provide positive synergies between human and ecosystem health, and culture offers an essential context for mediating positive dietary choices”.
| Population-level synergies linking biodiversity conservation and human nutrition in developing countries |
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While a good case can be made for the importance of biodiversity for providing nutrients and medicinal agents that can improve health, a strategy involving research, improved marketing, consumer education, policy and the strengthening of partnerships will reinforce the usefulness of biodiversity. The contributions of traditional foods and medicines to health and well-being are sufficiently understood to warrant a new prioritization of the marketing of forest foods within the context of strategies to support forest-based livelihoods and food-based approaches to health.
Basic research that can support these activities should include:
Developing-country scientists with knowledge of local resources, customs and cultural values should have a fundamental role in identifying sustainable approaches to improving diets and health. A growing body of reliable data collected in developing countries addresses the health properties of indigenous foods and medicines. Although a few developing countries can support extensive research and development programmes, in general progress will depend on improvements in the scientific resources, opportunities and infrastructure available.
Successful interventions to support the use of forest biodiversity for health objectives are likely to be multisectoral, multidisciplinary and problem focused. They will recognize dietary diversity as a fundamental, cost-effective and sustainable way of resolving health problems related to malnutrition, but also that diversity-based approaches to improving nutrition and health depend on the conservation and sustainable use of forest and other wild species and biodiversity.
Formulation and implementation of effective strategies involves the participation and integration of the expertise of multiple stakeholders from the scientific, health, government and private sectors. While few would dispute the importance of health and of environmental sustainability, different development sectors have different priorities. Dialogue is needed, for example, between environmentalists with concerns for underlying processes and health professionals focused on providing essential health care. Food systems and nutrition offer a common ground.
At the national level, ministries responsible for environment, health and nutrition, agriculture, forestry, economic development, culture and education could promote forest products within collaborative initiatives for human and ecosystem health, in conjunction with infrastructure and programme support for producers and marketers of priority foods. While international policy instruments such as CBD can offer direction to national initiatives, they also underline the need for coherent policies that unite environmental, health, agricultural and economic development priorities within the framework of the Millennium Development Goals.
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