Bioversity International

• Declining diversity brings a decline in nutrition
• Researching the links between local biodiversity and nutrition
• Tapping into local knowledge
• Selling the idea

The causes of malnutrition are complex, but chief among them is a general simplification of diets. In cities, people are increasingly deriving most of their energy from refined carbohydrates (chiefly wheat, rice and sugar) and processed fats and oils, which are currently cheaper than ever in many developing countries.

In many countries of the developing world, traditional and indigenous foods, which are often more nutritious than modern foods traded on the global market, are being neglected and forgotten.

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If a simplification in diet is responsible for a decline in nutrition levels, it follows that a diversification of diets could counter this trend. And there is considerable evidence to support this.

However, one of the most difficult tasks in promoting the nutritional benefits of a diverse diet is to measure the exact contributions made by individual components of the diet. This is difficult for a variety of reasons. Food Composition Tables, for example, a primary source of information about nutrition, give detailed analytical data about a wide variety of nutrients found in a wide variety of foods. But these tables tend to measure a single 'type' of food or else to average across several varieties or cultivars. This average measure can hide large differences. In rice, for example, some varieties contain 2.5 times more iron than others. Similar differences exist for other micronutrients, and indeed for some crops and some nutrients there can be hundredfold differences between varieties.

Furthermore, nutritional data on indigenous and traditional fruits, vegetables, condiments and spices are scanty and fragmented. One reason for this is that modern agriculture and nutritional sciences have not seriously considered the role of indigenous and uncultivated wild plants in the diets of rural and peri-urban populations.

We need to broaden our research into nutrition to include neglected and underutilized species and cover the range of the biodiversity that exists within individual species.

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If 'scientific data' fails to capture important information about local biodiversity of the foods in the diet, farmers and local consumers are often very aware of the nutritional properties of local plants and crops. They can describe certain kinds of food, and indeed certain varieties or landraces, as having a particular nutritional or therapeutic value.

Ethiopian farmers, for example, have identified at least three landraces of sorghum that contain about 30 percent more protein than other varieties. More importantly, they contain 50 to 60 percent more lysine (a limiting amino acid in sorghum) than average. These varieties are recognized as having value for sick children and nursing mothers.

In Nepal, studies of the traditional knowledge associated with local varieties of rice indicate that many have very specific health-related uses. A variety called Anadi is used for backache and to treat broken bones while another, Bayarni is considered particularly nutritious for pregnant and nursing women.

The Luo people of western Kenya say that the leafy vegetables that form an important part of the traditional diet protect against gastro-intestinal disturbances: at least one of them, Solanum nigrum, is powerfully effective against the protozoan gut parasite Giardia lamblia.

To complicate matters further, it isn't enough just to understand the nutritional content of particular plant varieties. Foods aren't eaten raw and separately from one another. They are prepared and eaten together in a cultural setting we call a 'meal'. The nutritional value of foods depends on how they are prepared and combined together.

So the challenge we face is to collect nutritional and health information using sound research methods and then to marry it, if necessary, to other kinds of analysis such as epidemiological and biochemical investigations.

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No matter what the research results indicate, research alone will not be enough to bring about change.

Many nutritious crops varieties, precisely because they are so important to the poor, are stigmatized as poor people's food. It often takes well-designed public awareness campaigns to change people's opinions about local foods.

What's more, it isn't enough to inform rural communities about the nutritional benefits of local crops. If biodiversity is to have a major impact on nutrition levels, also urban consumers will need to be made aware of the health properties of local produce. And of course, it will not be enough simply to tell consumers that these foods are good for them. If these products are not fresh, or not processed in ways that are tasty, or not marketed in an attractive way, they will not be eaten.

Building effective market chains linking farmers to urban consumers is an essential part of making local biodiversity a factor in tackling the widespread problem of hunger and malnutrition.

In many countries, consumers are rediscovering the value of traditional foods. International movements like Slow Food are raising awareness of the nutritional properties and tastiness of locally grown and locally processed foods. We need to build on these movements and create a greater appreciation of local food cultures. Keeping these cultures vibrant will be a big part of the solution to the problem of hunger and malnutrition.

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