1 This article presents views of FAO staff working in the areas of small animal husbandry, horticulture, oil-palm promotion, agricultural industries, women's programmes, nutrition programmes, food control, fishery industries, community forestry and development support communication. For further information, please contact Dr F. Simmersbach, Food Policy and Nutrition Division, FAO.
Prévention des carences en micronutriments: rôle essentiel de l'abondance et de la diversité des aliments
La importancia de una alimentación abundante y variada en la prevención de la carencia de micronutrientes
Worldwide, a staggering number of people lack adequate amounts of foods that are rich in the vitamins and minerals needed for health and a productive life, Lack of iron in the body is the most widespread nutritional disorder, affecting 2 000 million people, This deficiency causes an estimated 20 percent of maternal deaths in developing countries. Vitamin A deficiency is widespread among some 40 million children, increasing their vulnerability to infection and death, Each year 500 000 children become blind because their diets lack enough vitamin A, Approximately 1 000 million people are at risk of iodine deficiency, which causes goitre and, in the extreme, cretinism (FAO, 1992), In the face of this bleak situation an international mobilization is taking place to bring about a dramatic reduction of micronutrient deficiencies within this decade.
Food is the key to achieving these goals in a sustainable manner, The call for foods that are rich in micronutrients, available in sufficient quantities and accessible to people in need all year round presents a great challenge to those working in agriculture, fishery, forestry, small animal husbandry, industry, marketing, communication, women's organizations, home economics and nutrition, The wide application of proven technologies and approaches in these fields, as well as the development of new concepts, would go a long way towards solving micronutrient deficiency problems, The results of research must be transmitted to farmers and consumers and the experiences gained in research must be shared so that nutritional deficiencies can be prevented.
L'alimentation joue un rôle essentiel dans la prévention et la réduction des carences en micronutriments qui touchent des millions de personnes dans le monde. Cela suppose que les populations dans le besoin puissent disposer toute l'année de quantités suffisantes d'aliments riches en micronutriments, et c'est là un grand défi à relever. L'article passe en revue les possibilités d'améliorer la consommation d'aliments riches en vitamines et en éléments minéraux par une action ciblée dans des secteurs tels que agriculture, pêches, forêts, petit élevage, industrie, commercialisation, communication, associations féminines, économie domestique et nutrition.
Les aliments d'origine végétale assurent la majeure partie des micronutriments dont disposent les populations pauvres, car Ils sont relativement peu coûteux et facilement accessibles. On peut, grâce à une sélection rigoureuse, disposer de toute une gamme de fruits et légumes qui, pouvant être cultivés toute l'année, garantissent un apport constant en vitamines A et C. Les aliments traditionnels que l'on trouve dans la nature peuvent être de bonnes sources d'éléments minéraux et de vitamines; ils présentent en outre l'avantage d'être adaptés aux conditions locales et d'être acceptés dans les régimes alimentaires locaux.
Les animaux sont une bonne source de micronutriments, notamment de fer et de vitamine A. Il est fortement recommandé d'encourager le petit élevage pour améliorer la disponibilité de micronutriments; cette activité peut être intégrée de façon durable dans les travaux des fermes familiales. L'article examine également, comme pour les produits végétaux, toute une série d'animaux et de produits animaux adaptés aux pays en développement et acceptés par les consommateurs locaux.
Le poisson est une source de protéines, d'énergie (matières grasses) et d'acides gras essentiels, ainsi que de vitamines et d'éléments minéraux, II y a eu une hausse des prix du poisson, car l'offre baissait alors que la demande augmentait. En conséquence, la consommation de poisson a diminué dans les sociétés les plus pauvres. Un appui devrait être fourni pour les poissons les plus riches en éléments nutritifs et les plus accessibles aux consommateurs pauvres.
Les feuilles, graines, noix, fruits, racines et tubercules spontanés que l'on trouve dans les forêts contiennent beaucoup de vitamines et d'éléments minéraux essentiels, mais aussi des protéines, des matières grasses et des glucides. Les aliments d'origine forestière occupent une place importante dans les régimes alimentaires lorsque les aliments cultivés se font rares. On peut, à l'aide de divers moyens de conservation des aliments, remédier au caractère saisonnier des approvisionnements; avec le séchage d'aliments riches en éléments nutritifs, par exemple, il est possible d'améliorer les régimes alimentaires et d'accroître les revenus. L'article décrit, a ce propos, quelques techniques simples et peu coûteuses.
Pour assurer aux nourrissons un apport adéquat en micronutriments, il faut encourager l'allaitement au sein et améliorer la nutrition des mères. L'élimination des carences en micronutriments passe également par un changement des comportements alimentaires. Il faudrait introduire dans les écoles des cours de nutrition, destinés tant aux garçons qu'aux filles, et fournir des informations nutritionnelles au grand public, par le biais des médias.
Dans les pays industrialisés, l'enrichissement des aliments joue un rôle important dans la satisfaction des besoins en micronutriments de la population, L'enrichissement a la vitamine A et a l'iode contribue de façon essentielle à lutter contre certaines carences en micronutriments dans le monde entier, notamment dans les pays en développement. Le choix des aliments à enrichir se fait en fonction des modes de consommation, de la disponibilité des aliments et des aptitudes techniques à l'enrichissement. Les règlements et les contrôles des aliments contribuent de façon fondamentale à l'adoption de méthodes adéquates d'enrichissement des aliments.
On dispose d'un grand nombre d'options pour assurer un approvisionnement adéquat en aliments sûrs et riches en micronutriments, On peut, en intervenant aussi au niveau de l'éducation, améliorer la consommation et empêcher l'apparition de dangereuses carences en micronutriments. Si l'on veut préserver la santé et l'état nutritionnel de la population et réduire la dépendance à l'égard de produits pharmaceutiques pour le traitement des carences, il faudra agir sur divers plans; production adéquate d'aliments riches en éléments nutritifs, stockage, préservation et transformation appropriés des produits et, enfin, distribution équitable des approvisionnements alimentaires. Finalement, l'approche alimentaire, c'est l'espoir de fournir durablement aux populations les moyens de se charger de leur propre santé et de leur état nutritionnel.
La alimentación es esencial para prevenir y reducir la carencia de micronutrientes que afecta a millones de personas en todo el mundo. Para ello, es preciso disponer de alimentos ricos en micronutrientes a los que las personas necesitadas puedan acceder en cantidades suficientes durante todo el año, lo que entraña una enorme tarea, Se está estudiando la posibilidad de mejorar el consumo de alimentos ricos en vitaminas y minerales mediante actividades centradas en la agricultura, la pesca, la silvicultura, las pequeñas explotaciones ganaderas, la industria, la comercialización, la comunicación, las asociaciones de mujeres, la economía doméstica y la nutrición.
Las plantas comestibles constituyen la principal fuente de micronutrientes para las poblaciones pobres. ya que son relativamente baratas y asequibles. Mediante una cuidadosa selección, es posible cultivar a lo largo de todo el año una serie de frutas y hortalizas que proporcionen un suministro constante de vitaminas A y C. Los alimentos silvestres tradicionales pueden ser también una buena fuente de minerales y vitaminas, con la ventaja de adaptarse a las condiciones del lugar y a los hábitos alimentarios locales.
También los animales son importantes en el suministro de micronutrientes, especialmente hierro y vitamina A. La cría de ganado a pequeña escala resulta muy adecuada para mejorar la disponibilidad de micronutrientes, pudiendo integrarse en los sistemas agrícolas familiares de forma sostenible. Al igual que en el caso de las hortalizas, se están estudiando las variedades de animales y productos derivados que se adaptan a las condiciones de los países en desarrollo y son aceptados por los consumidores.
El pescado proporciona proteínas, energía en forma de grasa y ácidos grasos esenciales, así como vitaminas y minerales. La reducción de las capturas y el incremento de la demanda han hecho aumentar los precios del pescado, y en consecuencia, el consumo esta disminuyendo en las sociedades mas pobres. Deberían apoyarse las especies de peces que resulten mas provechosas desde el punto de vista de la nutrición y más asequibles para los consumidores pobres.
Las hojas, semillas, nueces, frutos, raíces y tubérculos silvestres que se encuentran en los bosques contienen muchas de las vitaminas y minerales esenciales, así como proteínas, grasas e hidratos de carbono. Los alimentos procedentes de los bosques son un componente importante de la alimentación en las estaciones en que los alimentos cultivados escasean. Asimismo, los problemas de suministro de tipo estacional pueden resolverse mediante el empleo de técnicas de conservación de los alimentos. El secado de alimentos ricos en nutrientes puede mejorar la dieta y aumentar los ingresos, y existen técnicas sencillas y baratas para la desecación de alimentos.
El apoyo a la lactancia materna prolongada y a una mejor alimentación de las madres ayuda a asegurarse de que los lactantes reciban los micronutrientes necesarios. Para acabar con las carencias de micronutrientes es preciso, asimismo, modificar los hábitos alimentarios. La educación y capacitación sobre nutrición de hombres y mujeres, deben formar parte de los sistemas de enseñanza, mientras que los medios de comunicación pueden servir para facilitar información al público en general.
El enriquecimiento de los alimentos constituye una medida importante para satisfacer las necesidades de micronutrientes de la población en los países industrializados, El enriquecimiento con vitamina A y yodo son fundamentales para luchar contra la malnutrición específica por carencia de micronutrientes en todo el mundo, especialmente, en los países en desarrollo. La elección de los alimentos que deben enriquecerse se realiza teniendo en cuenta los modelos dietéticos, la disponibilidad y las posibilidades técnicas para el enriquecimiento. El control de los alimentos y la legislación alimentaria son fundamentales para garantizar unas buenas prácticas de enriquecimiento.
Las opciones que existen para asegurar el suministro adecuado e inocuo de alimentos ricos en micronutrientes son enormemente variadas. En combinación con la educación, pueden contribuir a mejorar el consumo y a evitar las situaciones, peligrosas e inaceptables, de carencia de micronutrientes. La producción adecuada de alimentos de alto valor nutritivo, la utilización de métodos apropiados de almacenamiento, conservación y elaboración de alimentos y su distribución justa permitirán mantener unas buenas condiciones de salud y nutrición y reducir la dependencia de los productos farmacéuticos en el tratamiento de estas carencias. Por último, este planteamiento basado en los alimentos encarna la esperanza de hallar los medios sostenibles que faculten plenamente a la población para asumir la responsabilidad en lo que respecta a su salud y estado de nutrición.
Micronutrient content of selected plant and animal foods
Teneur en micronutriments d'aliments végétaux et animaux sélectionnés
Contenido de micronutrientes en determinados alimentos vegetales y animales
|
Food |
Vitamin A a |
Iron b |
Vitamin C c |
|
Animal | |||
|
Beef liver |
840 |
7.5 |
71 |
|
Poultry |
80 |
0 |
0 |
|
Butter |
730 |
0 |
0 |
|
Eggs (chicken) |
200 |
2.9 |
0 |
|
Plant | |||
|
Red palm oil, fresh |
4200 |
0 |
0 |
|
Carrot |
1000 |
1.6 |
15 |
|
Amaranth leaves |
380 |
8.9 |
50 |
|
Mango |
400 |
0.8 |
32 |
|
Papaya |
95 |
0.4 |
64 |
|
Average daily requirements per person | |||
|
Young child |
400 m g |
4 mg |
20 mg |
|
Adult male |
600 m g |
8 mg |
30 mg |
a Retinol equivalents in m g per 100 g edible portion, raw. A retinol equivalent is defined as 2 m g retinol, which is equal to 6 m g ß-carotene or 12 m g mixed provitamin A carotenoids.b mg iron per 100 g edible portion, raw.
c mg vitamin C per 100 g edible portion, raw.
Source: Retinol equivalent values calculated from West, Pepping & Temalilwa, 1988; others from FAO, 1982.
Food sources of micronutrients
Fruits and vegetables
It is the poor and socially deprived who are most affected by micronutrient deficiencies which are often part of the general malnutrition syndrome. Poor people obtain most of their nutrients from food plants, which are cheaper and more accessible than animal foods.
In humid tropical countries, green leafy spontaneous plants such as Amaranthus spp., Corchorus spp., Bidens pilosa, Gynandropsis spp., Celosia spp,. Basella spp., Solanum scabrum, Solanum americanum, Hibiscus sabdariffa and Vigna unguiculata often grow wild, Traditionally, they have been consumed as leafy vegetables when climatic conditions make the cultivation of exotic vegetables more difficult. The leaves of these plants tend to be good sources of protein, phosphorus and iron as well as vitamins A and C and in some cases B-group vitamins. In many cases they are of higher overall food value than introduced vegetable species, for example cabbage.
Many of these spontaneous plants can be successfully cultivated, It is expected that agronomic and genetic improvement programmes can identify higher-yielding genotypes and define productive crop management and seed production technologies, Rustic varieties could be selected which are tolerant of poor soils and resistant to drought or heat stress, thus extending the growing and harvest period significantly, Such investments can increase the availability of crops that grow well under marginal agroclimatic conditions. Since they are among the foods already accepted by consumers, these plants can contribute significantly to improving local access to dietary sources of micronutrients.
Horticultural crops are good sources of the vitamin A precursor B-carotene, Through careful selection, a range of fruit and vegetable crops can be cultivated throughout the year to provide a constant supply of vitamin A, For example, yellow or orange perennial fruits (e.g. apricot, mango, papaya, jackfruit, prickly pear, cape gooseberry) and fruit vegetables (e.g. tomato, pumpkin, squash, gourds, eggplant), some root vegetables (e.g. carrot and yellow-fleshed sweet potato) and most dark green leafy vegetables are generally moderate to good sources of vitamin A, Also, some local indigenous trees produce leaves and fruits that are rich in micronutrients and that are consumed in rural areas, i.e. Adansonia digitata and Parkia biglobosa.
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THE UNIQUE ROLE OF OIL-PALM PRODUCTION The richest natural plant source of provitamin A is the oil of the oil-palm Elaeis guineensis, and where production of the tree is widespread, e.g. in the western African coastal countries, the oil has become an important daily ingredient of the diet. Consequently, vitamin: A deficiency is not a general public health problem in these countries. However, in certain northern parts of Benin, Ghana, Nigeria and northwestern United Republic of Tanzania where climatic and hydrologic conditions prevent palm-oil production from being established, clinical optical signs of vitamin A deficiency are found, Improved internal marketing could partially overcome these local problems. Access to this nutritionally valuable oil can also be increased through raising extraction yields by improving village technology. This has been successfully promoted by FAO in the Luapula valley in Zambia. Technicians from Zambia are studying village extraction techniques in Ghana and adapting them to raise extraction rates by 50 percent. Better still is the introduction of higher-yielding varieties, As an example, FAO has shipped seedlings of tenera palms from Costa Rica to the Luapula region to replace the existing dura palms. These oil-palms will be used not in large-scale plantings but primarily as a yard crop, which will permit ready access to oil-palm fruit even for the poorest people in the community, The introduced variety is cold resistant, bears fruit after only two years (compared with the normal three to four years) and yields up to twice as much oil. When these trees are planted in community plots they will help prevent vitamin A deficiency in a sustainable way and enrich children's diets with fat, which is often lacking, In Brazil a local tree called "burité" produces oil as rich in B-carotene as that of the oil-palm, and this is being promoted as part of the national efforts to prevent vitamin A deficiency. |
For horticultural crops, staggering planting dates in the case of short-cycle crops and choosing a mixture of early maturing, average and late-maturing varieties for both annual and perennial crops can extend the harvest period, For instance, some varieties of mango trees can be harvested three times a year, with flowering, first budding, ripening and harvesting stages occurring simultaneously on different parts of the same tree. Thus, the problem of seasonality of available nutrients, in this case primarily ß-carotene, is overcome.
Since there can be considerable intercultivar variability in vitamin A content, inclusion of high carotene content among the parameters for selection may be worthwhile in crop genetic improvement programmes. This is one means of increasing the availability of vitamin A-rich foods to the population at large. For example, carrots of the Beta III variety produce three times the amount of carotene found in other carrots.
Several horticultural crops have a high natural content of vitamin C (e.g. citrus, guava, carambola, capsicum, parsley, white potato, strawberry). Vitamin C facilitates the absorption of iron found in plants, These plants are worth promoting as components of cropping systems at both the household and commercial levels.
The pursuit of horticultural crop cultivation presents rather different challenges under low-temperature conditions such as those found in the remote highlands of certain developing countries (e.g. Afghanistan, Bhutan, Lesotho and Nepal), In such areas, efforts to extend the production of leafy vegetables, for example, into the winter season need to be based on the selection of cold-tolerant cultivars of Brassica crops such as kale and mustard. Alternatively, locally appropriate protected cultivation practices can be adopted, such as simple low plastic tunnels or hotbeds, which accumulate solar heat and shield crop plants from exposure to low temperature extremes and wind.
The role of women in home and community gardens is of special importance, In addition to being responsible for producing their crops on small plots of land, women often have good knowledge of indigenous species of green leafy vegetables, of how to prepare them and of how to preserve both seeds and produce. This is especially true of elderly women. In local markets, the main vendors of these crops (fresh or dried) are often women, Extension, credit and agricultural inputs should be directed towards women, but often are not. FAO promotes the organization of women's groups to make women eligible for inputs and to improve the efficiency of their work.
Fruits and vegetables are crucial in efforts to prevent micronutrient deficiencies, Fortunately, fruits and vegetables are abundant and are rich in carotenes (provitamin A), iron and vitamin C. While fruits and vegetables are commonly the main sources of micronutrients, the role of some staples must not be forgotten in this context, Researchers in Asia have developed sweet potatoes with a deep yellow or orange flesh containing several times more carotene than the common white varieties. Not only the tubers are of value; the leaves also contain important nutrients, For example, the leaves of taro (Colocasia esculenta) are used to enrich local dishes with micronutrients in countries of Asia and the Pacific. In many African countries of the humid tropics cassava leaves (Manihot esculenta) are also consumed. Millets are rich sources of iron compared with other cereals such as wheat or maize.
Small animals
Foods from animal sources, i.e. meat, eggs and milk, provide large amounts of protein and essential amino acids. They are also valuable sources of micronutrients, contributing greatly to protecting a large number of people from the serious consequences of micronutrient deficiencies.
Significant amounts of vitamin A are found in eggs of domesticated animals as well as in milk, and liver is especially rich in this vitamin. The highest vitamin A content is found in sheep (20 mg per 100 g meat), while the meat of fowl also provides a valuable amount. Among the various types of fowl, goose and duck are especially rich in fat as well as vitamin A, The content of iron in small mammals such as rabbits, and in fowl, is reasonable (1.5 mg per 100 g meat). The inner organs (i.e. liver, kidney, heart, lung) of all species are rich in iron.
Sheep's milk is approximately one-third richer in vitamin A than cow's milk. While iodine is available in milk, the amounts depend on the iodine content of the feed given to the animals, It may be useful in this context to give iodized salt to milk-producing animals.
In the light of these facts, small animal husbandry is strongly recommended to improve the availability of micronutrients, especially vitamin A and iron, For self-sufficiency, small animal husbandry can be integrated within farm systems in a sustainable manner.
Depending on the region and food habits, sheep and goats can contribute significantly to fulfilling a family's nutritional needs. Considering that the potential milk production of an animal is between 200 ml and 1 litre per day, an important portion of nutrient needs can be met.
Worldwide, humans consume eggs from a variety of bird species, Although chicken egg production is the most important, duck and quail eggs are highly appreciated in Asian countries, In Africa, the eggs of the guinea fowl are popular, especially in dry regions where the climate permits long conservation. The egg not only provides a complete set of essential amino acids in optimal proportions, it is also an excellent source of vitamins, including vitamin A. New varieties of scavenger chickens, which produce more eggs than the old varieties, have been bred in India, Scavenger chickens do not demand the special techniques and investment involved in chicken raising, which often hinder poor farmers from benefiting from higher egg production.
The sale of animal products also provides valuable cash to poor farmers who can then meet their micronutrient requirements from plant sources, Women often have primary responsibility for small animal husbandry (e.g. the raising of goats, sheep and chickens) and the preparation of products from animals (cheese, butter, yoghurt), It is usually women who decide whether to sell eggs and other products or to use them for home consumption. Unfortunately, the price of these foods, especially in urban areas, is usually high and beyond the reach of poor consumers who may be afflicted with micronutrient deficiencies.
Fish
Fish is a good supplement in most diets, Although generally cheaper than meat and meat products, fish is still expensive. It is often difficult to increase the availability of fish at affordable prices, Promotion of consumption is mainly relevant when sufficient resources of low-priced fish are available, There are also some prospects for community-based aquaculture as part of the household farming system.
Fish provides protein, energy from fat and essential fatty acids, as well as vitamins and minerals. Fish species vary considerably in their composition as well as in size and appearance. Marine fish are advantageous in comparison with freshwater species by virtue of their higher iodine content.
Fresh fish processing (primarily drying and smoking) and marketing is often managed by women, Education about the strict hygienic handling required by fish should be provided to women who sell fish as well as to their clients, Food purchasers, who also tend to be female, may be unaware of the health advantages of fish sold on ice and therefore unwilling to pay more for this, Nutrition education is therefore often a complement to fish promotion.
Trees and forest products 2
2 Figures used in this section are drawn from a paper presented at the Committee on Forestry, 11th Session, Rome, 2-12 March 1993: Item 7, "Forestry and nutrition".
Forests and trees provide foods that supplement and complement traditional agricultural sources. Wild leaves and fruits contain many essential vitamins, Seeds, nuts, roots and tubers found in forests supply fats and carbohydrates, Mushrooms, gums and saps provide protein and minerals. Wild animals from the forest often supply most of the meat consumed by people living in or near forest areas.
In Swaziland it was found that wild leaves supply as much carotene, vitamin C, calcium and iron as leaves from cultivated plants and that 48 varieties of leaves were used by half of all adults, Children in lowland Kenya and Swaziland snack on forest foods which provide an important supplement to their diet, especially during winter months, The seeds from Parkia species provide a nutritious protein- and fat-rich food known as "dawadawa" in Nigeria, In the Melanesian region, a study showed that palm sago provided a staple carbohydrate for 300000 people, In Java, Indonesia, home gardens combining trees and horticultural crops are an important form of agroforestry and provide more than 40 percent of the total calories consumed by some farming communities. In Nigeria, traditional home gardens can contain more than 60 species of trees that provide food products, Forest foods are extremely important because they are frequently available when agricultural crops are in short supply. For example, in Bangladesh tree fruits are available during one of the two lean periods. In northern Brazil, babassu palms bear fruit in the off-peak agricultural period; their fruit and kernels make a significant dietary contribution in this season, With the help of communities, nutritionists, social scientists and foresters, forestry development activities can focus on enhancing nutritional well-being.
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COPING WITH DWINDLING SUPPLIES OF FISH Sadly, most of the world's fisheries have reached or will soon reach their maximum sustainable yield. Market supplies of fish are decreasing relative to the growing demand for fish products, effecting a rise in prices. Consequently, fish consumption is dropping in poorer societies, not least in Africa. To cope with this challenge, nutritional analysis of the fish species available to specific populations can be made and the most beneficial of the fish consumed by relatively poor and undernourished populations can be given support. For example, in eastern and southern Africa the small sardine-like fish (dagaa, kapenta, chisense, etc.) in the freshwater lakes in the Rift valley are sun-dried and transported to local and larger markets. The fish are sold as an ingredient in the sauce eaten with a stiff porridge of banana, maize or cassava. Even large families who cannot afford more than a small handful of sardines can gain considerable benefits from using dried, whole sardines as a condiment. Whole fish are of much more varied and useful nutritional value than, for example, fillets, Dried fish are usually pulverized before cooking and include the bones, which provide calcium. The infernal organs consumed in ungutted fish contain appreciable amounts of iron and vitamin A precursors, Thus, a small amount of sardine consumed whole is an excellent form of animal protein supplement. Market studies also show that lake fisheries provide millions of Africans with these essential micronutrients, However, excessive quantities of fluorine may constrain consumption. Unfortunately, sardine prices are rising, not least because of competition with other users such as fish-meal manufacturers and producers of feed for livestock and poultry. Rapid development in production of such feed could threaten diets throughout the region. Thus, a soundly based fishery/nutrition policy together with good regulation and management is needed. As an interim measure, FAO lake fisheries projects focus on improving sardine catch methods and processing methods in order to raise production and reduce wastage, Another goal is to improve surveillance of sardine stocks as a basis for informed management of this fishery. The needs of human consumers of sardines are considered in the United Republic of Tanzania, where FAO has a nutrition-in-fisheries project regarding fisheries developments on Lake Victoria. |
Preservation of micronutrient-rich foods to overcome seasonal shortages
Seasonality is a major barrier to obtaining the benefits of fruits and vegetables, especially in tropical countries, Horticultural products mature during a short season, most of them simultaneously, in quantities much higher than the local markets can absorb, During the harvest season, low prices cause farmers to refrain from selling their produce, Drying of nutrient-rich foods (e.g. mango and green leaves) can improve a family's nutritional status and its income, since dried foods can bring a good market price.
Worldwide, from Niger to the northern areas of Pakistan, women are using solar drying techniques for fruits and vegetables that contain important quantities of vitamin A and iron, Their sale at local markets provides valuable income, Mango leather (concentrated mango pulp in sheets), often sold by women on the street, is being introduced as a snack for schoolchildren.
Need for nutrition information, education and communication
Nutrition information and education are needed so that people can make informed choices about the foods they grow, purchase and eat, Indeed, the success of food-based strategies to eliminate micronutrient deficiencies will rest on the willingness of individuals to change their dietary behaviours. However, information and education must extend beyond the level of the individual, since social, economic and political factors also determine food patterns.
Attitudes towards breast-feeding illustrate the effects of society on nutrition. Breast-feeding not only provides all of the nutritional needs of the infant in the first six months of life, but also protects the baby from illness, both during breast-feeding and after the baby is weaned. Poor weaning diets with too much bulk, too little variety, too much water, too little protein or too few micronutrients will jeopardize the child's development and nutritional status. Efforts to ensure mothers' good health and nutritional status are a must for preventing micronutrient deficiencies in women as well as newborns. Where social influences are reducing the length of breast-feeding, teachers, health workers and extension workers should be educated to support breast-feeding and appropriate weaning practices.
Since women are usually those most responsible for food within a household, nutrition education Is primarily addressed to them. However, males in a household also influence which foods are consumed. Nutrition education and training should be given to males and females and introduced into the curricula of primary and secondary schools as well as agricultural schools and universities.
The mass media are precious communication tools which can be used in many ways for a variety of purposes, Through the mass media all members of the public can be reached and can receive the same information with consistent messages. Knowledge of communication techniques is a prerequisite for developing effective nutrition education programmes. In the Sahel, FAO is training national teams of communicators and nutritionists to respond to nutritional problems such as vitamin A deficiency with the use of mass media. Rural radio, for example, is used to create a dialogue between villagers and educators on food and nutrition problems and to broadcast nutrition and health improvement messages respecting local customs. Slide programmes, filmstrips, flip charts, posters and videos are produced based on information obtained from the villagers themselves. These culturally appropriate tools will be used for nutrition education in group activities with the active participation of the people.
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IMPROVED DRYING TECHNIQUES PRESERVE NUTRIENTS Since ancient times the most common method of preserving fruits and vegetables, as well as meat and fish, has been sun drying. Reducing the moisture in the food prevents the growth of microorganisms that cause foods to decay, At the same time enzymatic and biochemical activities are practically stopped or reduced to very low levels, Foods preserved by drying can be kept at ambient temperatures for long periods and provide nutrients when fresh produce is not available. Open-air sun drying has disadvantages, such as infestation by insects, contamination from dirt, rodents and birds, and spoilage from occasional rains. The use of solar dryers, an alternative to sun drying, provides the benefits of higher air temperature and continuous air flow which substantially improve the drying rates. This results in a higher quality product, Since closed cabinets are used for solar drying, the product is more protected. The solar dryer is based on the principle of absorption of heat from solar radiation by a black surface. The temperature inside a solar dryer can be maintained at 60° to 70°C, which minimizes the damage to vitamins and other nutrients. Recent results obtained in the laboratory by using high-pressure liquid chromatography(HPLC) to separate the carotenoids show that carotene retention after solar drying is around 40 to 80 percent depending on the product, which is much higher than retention following traditional methods of drying. For example, fresh cowpea leaves have 2 435 m g retinol equivalent (RE) per 100 g while solar-dried leaves have 2071 m g RE per 100g. Leaves dried in the traditional manner had only 847 m g RE per 100 g. Solar dryers do not require sophisticated building materials, A family-type solar dryer can be built for as little as US$10, while the price of a community-sized dryer, which can be used by all members of a village, may reach US$250 |
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COMMUNITY MEMBERS PROMOTE MICRONUTRIENT-RICH FOODS Involving all members of a community facilitates dietary change. As part of an FAO nutrition project, a village in Niger organized a recipe competition in which traditional foods rich in micronutrients were used, Men, children, school teachers and community workers were invited to be the judges of the foods produced. The competition was widely promoted and women were motivated to do their best. Many villagers were surprised to find that they actually enjoyed foods that until that time they would not have eaten, This alone made it easier for them to accept suggestions to change their eating habits. At this point, they were ready to support changes in the family diet. By involving everyone in the community, the organizers created a supportive environment in which changing behaviour became desirable, Because the activity educated various segments of the population in addition to the primary target group, its results became a stimulus for further change. |
Micronutrients and food control
The practice of fortification - the addition of essential nutrients to foods for prevention or correction of a dietary deficiency - is becoming increasingly widespread as a means of satisfying the community's micronutrient requirements. This is especially the case where deficiencies cannot be corrected through an abundance of a wide variety of foods. The fortification of salt with iodine is a good example.
In industrialized countries a wide range of foods are fortified with many different micronutrients including vitamin A, the vitamin B complex, iron and iodine. Although fortification is less common in developing countries, it is nevertheless important and is practised at the national, village and individual levels, Globally, fortification has done much to correct what were once common micronutrient deficiencies and to reduce resultant disabilities significantly.
Food fortification has a long history of success through nationally coordinated programmes, Fortification of sugar with vitamin A has been practised in Costa Rica, Guatemala, Honduras and Panama, and in some parts of Pakistan and the United Republic of Tanzania tea is fortified with vitamin A, Recently, fortification of monosodium glutamate (MSG) with vitamin A commenced in Indonesia and the Philippines. Double fortification of some carriers (e.g. salt with iron and iodine in India and rice with iron and vitamin A in Brazil and the Philippines) has been achieved.
The World Food Programme (WFP), the European Community (EC) and other national and international organizations involved in humanitarian assistance distribute foods fortified with micronutrients including dried skim milk powder enriched with vitamin A.
Successful fortification is not as simple as it might first appear; it involves much more than throwing a handful of micronutrients into a bag of flour or dried milk powder. To be effective, fortification requires informed decisions about such things as the proper level of enrichment (too little may be useless, too much could be a health hazard); the foods suitable as vehicles for fortification, i.e. compatible with the micronutrient and consumed sufficiently widely; the fortifying substances to be used; and the process of fortification to be adopted, for example mixing, coating, infusion or extrusion, Product packaging, storage and marketing practices also need to be taken well into account.
To ensure that fortification is successful, that the health of consumers is protected and that fortified foods are what they claim to be, it is essential that fortified foods be subject to food control - that is, that they be monitored officially by means of inspection and analysis for compliance with nationally accepted quality and safety requirements.
Food control becomes critical in the evaluation and endorsement of the fortification process, of the efficiency and safety of the micronutrient materials selected, of the suitability of end-product packaging and storage and of the labelling of the product to ensure that it is correct and does not mislead the consumer. Without an effective food control system and the monitoring it involves, it is extremely difficult to have successful micronutrient fortification.
Conclusion
The variety of options for ensuring an adequate and safe supply of micronutrient-rich foods is impressive, When these foods are combined with nutrition education for the public, food control and inspection and training of technical staff, good use of food supplies can be ensured, This could lead to improvements in food consumption and prevent unacceptable and dangerous micronutrient deficiencies.
The natural elements for maintaining good health and nutritional status are adequate production of nutritionally rich foods; appropriate food storage, preservation and processing; and fair distribution of food according to physiological requirements, Where these occur there is a high possibility of weaning those individuals who have become dependent on pharmaceuticals from a costly approach that has only short-term effects, Moreover, the food-based approach embodies the basis for sustainability and the hope of fully empowering people to take their health and nutritional status into their own hands.
References
FAO. 1982. Food composition tables for the Near East. Rome
FAO. 1992. Creating a well-fed world. Rome.
West, C.E., Pepping, F. &Temalilwa, C.R., eds. 1988, The composition of foods commonly eaten in East Africa. Wageningen, the Netherlands, Wageningen Agricultural University.
