AFRICAN JOURNAL OF FOOD & NUTRITIONAL SCIENCES
(AJFNS)
online version ISSN 1681 - 9608
Volume 2 No. 2

Timothy Johns*

Given the complexity of human physiology and of food composition, and therefore the difficulty of precisely identifying optimal diets, diversity provides an intrinsic buffer against uncertainties posed by lack of knowledge and of change. Plant foods represent the largest segment of dietary diversity [1]. Within this context, the International Plant Genetic Resources Institute (IPGRI) is currently developing a global strategy to incorporate greater consideration of nutrition into its programs on conservation and use of plant genetic resources (PGR).

IPGRI, a member of the Consultative Group on International Agricultural Research (CGIAR), has its headquarters in Rome with regional programs in sub-Saharan Africa (SSA), the Americas, Asia, the Pacific and Oceania, Europe, and Central and West Asia and North Africa (CWANA). The regional office for SSA is in Nairobi with a sub-regional office for West Africa in Cotonou, Benin.

Through its mandate IPGRI works to advance the conservation and use of genetic diversity for the well being of present and future generations. The Institute encourages, supports and undertakes activities to improve management of genetic resources worldwide so as to help eradicate poverty, increase food security and protect environment.

Africa's fundamental importance for global PGR conservation stems from its richness in natural resources. Out of some 150 food crops used in Africa, 115 are indigenous African species. Africa is the centre of origin of several important crops, for example coffee, oil palm, yams, cowpea and sorghum [1]. Some of the world's major regions of crop diversity are found in Africa.

IPGRI works to ensure that ccountries in sub-Saharan Africa are able to access, conserve and use their plant genetic resources through national program development, support to networks, information and documentation, development of PGR methods and approaches, training and education and policy of legislation.

Prioritization of human health and nutrition coincides with IPGRI's current strategy to place more emphasis on the use of plant genetic resources (PGR). From IPGRI's perspective, diversity both within (intra-specific) and among (inter-specific) species is essential to enhancing nutrition and health. Diversity of biological resources is linked to diversity in cultural traditions, knowledge systems, and dietary practices and preferences. Thus human needs and traditional ecology are fundamentally important for the management and use of plant genetic resources [2].

Developing Linkages between Nutrition-Health and PGR Conservation

With increased awareness of nutrition and health priorities in agriculture and environmental sciences, and conversely the role of plant biodiversity to the international health community, scientists and institutions engaged in agriculture, environmental conservation and health respectively can better address contemporary problems through creating and taking advantage of opportunities to interact and work jointly.

Defining Nutrition and Health Priorities
Within health-related fields, plant biodiversity offers useful perspectives on a number of issues of contemporary scientific and public health importance. For example:
1) Micronutrient deficiency, including food-based strategies for addressing multiple concurrent deficiencies [3].
2) Bioavailability of provitamin A, iron and other nutrients from fruits and vegetables in addressing major micronutrient deficiencies in developing regions [3].
3) Nutrition and disease. As nutrition mediates immune function, diet and PGR have great relevance to addressing measles, HIV/AIDS and other diseases.
4) Nutrition transition precipitating the emerging epidemics of diabetes and CVD [2] as defined by lack of dietary diversity relative to increases in energy. Hypoglycemic properties know from many plants used in traditional diet and medicine [4] offer an important direction of investigation in relation to diabetes and other aspects of the dietary transition.
5) Medicinal plants as physiological mediators of health. Traditional concepts of health and healing often make minimal distinction between plants consumed in diet and medicine. Products that are ingested routinely, rather than those of specific pharmacological and curative interest comprise a range of biodiversity that is neglected both in PGR and health [4].

Research Directions and Relationships
Within the scope of these health priorities, a number of specific research activities linking nutrition and PGR conservation emerge.

Genetic Resource Conservation and Use. The wealth of genetic diversity present in gene banks and farmers' fields comprises a resource from which breeders can address nutritional problems in a targeted manner. Recognized successes in biofortifying crops through selection or genetic modification, such as ß-carotene-rich sweet potatoes of the VITTA program or Quality Protein Maize produced by CIMMYT, offer viable examples of this approach.

Genetic diversity can also contribute to increasing productivity and marketability in species that have nutritional and health benefits that are in demand.

Laboratory analysis can identify crop varieties and minor crops with selective nutritional assets and extend the evaluation of the nutritional content of indigenous fruits and vegetables and wild edible species. Related studies on bioavailability, effects of preparation and processing on intraspecific variability, and non-nutrient phytochemical constituents [4] such as xanthophylls, and functional properties of plants for example glycemic indices, are needed.

Databases on composition with emphasis on intraspecific diversity are essential complements to laboratory evaluations.

Biofortification is a potential use of genetic diversity to address problems of undernutrition in specific clearly-defined contexts. Nutritionists must contribute to evaluations [5] of efficacy and to ensure new products do not undermine cultural and biological diversity, community self-sufficiency and health.

Formulation and compilation of criteria and indicators for evaluating consumer quality (eg. sensory, nutritional, culinary, toxicological and medicinal properties) are essential for PGR conservation.

Dietary diversity indices focused on plants can be developed with the rationale of further establishing the importance of PGR and as simple, low-cost indicators of nutritional status in developing country contexts [1,6].

On-farm and community-based activities
Indigenous knowledge and culturally-defined values offer insights into health-related properties as well as the context in which health-positive behaviours and practices will be maintained and adopted. Participatory programs oriented to maintain the genetic diversity of cultivated and uncultivated plant species can bring together scientific information with indigenous knowledge to improve nutrition and contribute to economic livelihood. Nutrition and health also afford a valuable window on gender-specific knowledge and points of view. Indigenous food processing practices can direct studies on bioavailability.

Public health
In collaboration with the healthcare sector plant diversity research can define dietary solutions based on assessment of nutritional and health needs [6]. In relation to problems of urbanization these can consist of surveys on patterns of consumption of neglected and underutilized species (NUSs) (e.g. African leafy vegetables) and local varieties with attention to beliefs, attitudes and values concerning these plants. Innovative processing and marketing of traditional species and varieties, and education activities and cultural support programs on the benefits of consuming diversity of fruits and vegetables are needed.

Policy and Advocacy
Food selection and dietary diversity of malnourished people is determined by the availability, cost, and cultural acceptability of foods. As local food systems are increasingly integrated into regional and global markets, diversity can be understood and deployed with attention to incentives and constraints at institutional and economic levels. Success in encouraging food crop diversity may depend on empowering farmers through participatory plant breeding and agriculture support programs, providing them the means to make informed choices, and structuring pricing policies and market and commercial supports appropriately. Urban consumption may be influenced by the same factors, by strengthening cultural traditions of diet, and by modulation of urban agricultural patterns. IPGRI already engages in activities where nutrition and health are, or could be, relevant components. Additional undertakings in the developing nutrition-PGR strategy will compliment IPGRI's existing expertise. While IPGRI's success in nutrition and health will depend on defining the unique contributions that it can make, it also requires collaboration with other organizations. IPGRI's leadership can be in identifying and prioritizing research issues and key species of regional and global importance, and in promoting and coordinating activities. Consultation with current partners and a new expert advisory group is an essential aspect of this initiative.

REFERENCES

1. Hoddinott J and Y Yohannes Dietary Diversity as a Food Security Indicator. FCND Discussion Paper No. 136. IFPRI, Washington. 2002.
2. Popkin BM, Horton S and S Kim The Nutrition Transition and Prevention of Diet-related Diseases in Asia and the Pacific. Food Nutr. Bull. 2000; 22(suppl): 58.
3. Burlingame B What is a Nutrient? J. Food Comp. Anal. 2001; 14: 1.
4. Johns T and L Chapman Phytochemicals Ingested in Traditional Diets and Medicines as Modulators of Energy Metabolism. In: Arnason JT and R Mata (eds) Phytochemistry of Medicinal Plants, Recent Advances in Phytochemistry 29. Plenum Press, New York.1995.
5. King JC Evaluating the Impact of Plant Biofortification on Human Nutrition. J. Nutr. 2002; 132: 511s-513s.
6. Hatløy A, Torheim LE and A Oshaug Food Variety - a Good Indicator of Nutritional Adequacy of the Diet? A Case Study from an Urban Area in Mali, West Africa. Eur. J. Clin. Nutr. 1998; 52:891-898.

Honorary Fellow, Sub-Saharan Africa Group, International Plant Genetic Resources Institute (IPGRI), c/o ICRAF, P.O. Box 30677, Nairobi, Kenya;
Professor, School of Dietetics and Human Nutrition, Macdonald Campus, McGill University, Ste. Anne de Bellevue, Quebec, H9X 3V9, Canada. Email: t.johns@cgiar.org; johns@macdonald.mcgill.ca

|Home||Foreword||Comments| Editorial|Commentary |Policies||Research||Programmes||Students contributions||
|| Topical Issues||Activities||Events||Profile||Transition||Français Langue||Contact|

copyright©2002
Designed by Spacenet Online