Timothy Johns

Herbal remedies of the Luo of Siaya District, Kenya: establishing quantitative criteria for consensus

Data based on independent interviews with 45 herbalists of the Luo of Siaya District, Kenya, comprised 1129 remedy reports and related to 330 species of plants. While 49% of the remedies were encountered only once we list here 66 remedies (49 taxa) that were confirmed through independent reports from three or more individuals. A log-linear model was applied to these data in order to establish criteria for evaluating the likely efficacy of specific remedies. A quantitative interaction effect was calculated for each remedy as a measure of its degree of confirmation. The validity of the values derived from the mathematical model is considered in relation to classical criteria for evaluating ethnomedicinal reports.RésuméLes résultats d’enquêtes individuelles avec 45 herboristes Luo du district de Siaya au Kenya ont permis de répertorier 330 espèces de plantes médicinales utilisées dans quelques 1129 traitements herboristes. Puisque 49% de ces plantes médicinales n’avaient été mentionnées qu’une seule fois, nous avons bâti une liste de 66 plantes médicinales (49 taxa) dont chacune a été rapportée par plus de trois herboristes. Les résultats obtenus ont été incorporés dans un modèle logarithmique linéaire afin d’identifier des critères d’evaluation de l’efficacité de ces plantes médicinales. Pour chacune des plantes médicinales “l’effet de l’interactíon quantitative” a été utilisé comme mesure de son degré de confirmation. La validité des résultats obtenus à partir de ce modèle mathématique a été comparée aux critères classiques d’évaluation des rapports ethnomédicinaux.

Agricultural Biodiversity, Nutrition, and Health: Making a Difference to Hunger and Nutrition in the Developing World

Background In spite of the strides made globally in reducing hunger, the problems of micronutrient deficiencies and coexisting obesity and related cardiovascular and degenerative diseases constitute a formidable challenge for the future. Attempts to reverse this trend with single-nutrient intervention strategies have met with limited success, resulting in renewed calls for food-based approaches. The deployment of agricultural biodiversity is an approach that entails greater use of local biodiversity to ensure dietary diversity. Objective To outline a new strategy proposed by the International Plant Genetic Resources Institute (IPGRI) that employs agricultural biodiversity as the primary resource for food security and health. Methods The authors carried out a meta-analysis to review and assemble existing information on the nutritional and healthful properties of traditional foods based on a diverse set of case studies and food composition and nutritional analysis studies. The methods highlight particular examples of foods where analysis of nutrient and non-nutrient composition reveals important traits to address the growing problems of malnutrition associated with the rise of chronic diseases. Finally, the authors analyze social, economic, and cultural changes that undermine the healthful components of traditional diets. Results Based on this multidisciplinary and comparative approach, the authors suggest a holistic food-based approach that combines research to assess and document nutritional and healthful properties of traditional foods, investigating options in which nutritionally valuable traditional foods can contribute to better livelihoods, and ways that awareness and promotional campaigns can identify healthful components of traditional diets that fit the needs of urban and market-oriented consumers. Conclusions There is an urgent need for agricultural research centers, national agricultural research systems, universities, and community-based organizations to work together under a shared policy framework with the aim of developing a strong evidence base linking biodiversity, nutrition, and health. Although these initiatives are still ongoing, the gains realized in small-scale and local pilot efforts have encouraged IPGRI to work with local partners toward the implementation of scale-up efforts in various regions.

Xanthine oxidase inhibitory activity of northeastern North American plant remedies used for gout

Xanthine oxidase (xanthine: oxygen oxidoreductase EC 1.2.3.2) inhibitory activity was assayed from 26 species belonging to 18 families traditionally used for the treatment of gout and related symptoms by Indigenous people of northeastern North America. The degree of inhibition was determined by measuring the increase in absorbance at 295 nm associated with uric acid formation. Eighty-eight percent of the plants were found to have inhibitory activity at 100 microg/ml, with 20% having greater than 50% inhibition. Larix laricina exhibited the highest activity with an inhibition of 86.33%. Of the species with the highest activity, Lineweaver-Burk plots showed that inhibition mode was of linear mixed-type. Inhibitory activity of the plants correlated positively with their phenolic content (r = 0.52 P < 0.01) and tannin content (r = 0.59 P < 0.001).

Biocultural diversity in the sustainability of developing-country food systems

The policy implications of a model of contemporary food systems for developing countries that integrates nutrition, reduction of disease risk, culture, income generation, and biodiversity are reviewed within a theoretical and empirical examination of the relevance of nutrition to the priorities put forward at the World Summit on Sustainable Development in Johannesburg, South Africa, 2002. Agricultural, health, economic, and social policies with local reach are necessary responses to the increase in noncommunicable disease associated with the globalization of food systems. Nutrition offers a nexus for the changes in individual behavior and motivation essential for fundamental shifts in production and consumption patterns. Mutual consideration of biocultural diversity and nutrition can guide policy, research, promotion, and applied action in developing countries. Benefits from enhanced use of biodiversity must legitimately flow to the undernourished poor, while potential negative consequences must be minimized and mitigated. Quality and quantity of food need not be mutually exclusive. Functions related to energy density, glycemic control, oxidative stress, and immunostimulation define important research priorities. Tests of the hypothesis that biodiversity equates with dietary diversity and health might combine quantitative indicators of dietary and biological diversity with nutrition and health outcomes. Biodiversity, where it is part of traditional agricultural and food systems, can be best conserved and enhanced through rational use within a broad-based developmental focus on small-scale and low-input production. The fact that traditional systems, once lost, are hard to recreate underlines the imperative for timely documentation, compilation, and dissemination of eroding knowledge of biodiversity and the use of food culture for promoting positive behaviors.

Linking biodiversity, diet and health in policy and practice

Simplification of human diets associated with increased accessibility of inexpensive agricultural commodities and erosion of agrobiodiversity leads to nutrient deficiencies and excess energy consumption. Non-communicable diseases are growing causes of death and disability worldwide. Successful food systems in transition effectively draw on locally-available foods, food variety and traditional food cultures. In practice this process involves empirical research, public policy, promotion and applied action in support of multi-sectoral, community-based strategies linking rural producers and urban consumers, subsistence and market economies, and traditional and modern food systems. Implementation of the International Plant Genetic Resources Institutes Global Nutrition Strategy in Sub-Saharan Africa offers a useful case study. Relevant policy platforms, in which biodiversity conservation and nutrition are and should be linked, include the Millennium Development Goals, Millennium Ecosystem Assessment, Convention on Biological Diversity, Global Strategy on Diet, Physical Activity and Health, Food-Based Dietary Guidelines, Right to Adequate Food and UN Human Rights Commissions Permanent Forum on Indigenous Issues. The largely unexplored health benefits of cultivated and wild plants include micronutrient intake and functions related to energy density, glycaemic control, oxidative stress and immuno-stimulation. Research on the properties of neglected and underutilized species and local varieties deserves higher priority. In tests of the hypothesis that biodiversity is essential for dietary diversity and health, quantitative indicators of dietary and biological diversity can be combined with nutrition and health outcomes at the population level. That traditional systems once lost are hard to recreate underlines the imperative for timely documentation, compilation and dissemination of eroding knowledge of biodiversity and the use of food culture for promoting positive behaviours.

Inhibition of advanced glycation end product formation by medicinal plant extracts correlates with phenolic metabolites and antioxidant activity.

Nonenzymatic formation of advanced glycation end products (AGEs) is accelerated under hyperglycemic conditions characteristic of type 2 diabetes mellitus and contributes to the development of vascular complications. As such, inhibition of AGE formation represents a potential therapeutic target for the prevention and treatment of diabetic complications. In the present study, ethanolic extracts of 17 medicinal plants were assessed for inhibitory effects on in vitro AGE formation through fluorometric and immunochemical detection of fluorescent AGEs and N(ε)-(carboxymethyl)lysine adducts of albumin (CML-BSA), respectively. Most extracts inhibited fluorescent AGE formation with IC (50) values ranging from 0.4 to 38.6 µg/mL and all extracts reduced CML-BSA formation but to differing degrees. Results obtained through both methods were highly correlated. Antiglycation activities were positively correlated with total phenolic content, free radical scavenging activity and reduction in malonyldiadehyde levels following oxidation of low-density lipoprotein, but negatively correlated with lag time to formation of conjugated dienes. Together, these results provide evidence that antioxidant phenolic metabolites mediate the antiglycation activity of our medicinal plant collection, a relationship that likely extends to other medicinal and food plants.

Supplement use: Is there any nutritional benefit?

OBJECTIVE To examine the role of dietary supplements in improving total nutrient intakes in adults. DESIGN Dietitian-administered 24-hour recalls (of intake including supplements) were conducted in 1997 and 1998. Supplement users were categorized into groups based on the types of supplements used and nutrient intake was examined. SUBJECTS Using a multistage, stratified random sampling, 1,530 Canadian adults aged 19 to 65 years were surveyed. STATISTICAL ANALYSES PERFORMED Intakes from diet, supplements, and diet plus supplements were examined by age/gender stratification. RESULTS Supplement users had dietary intakes, from food alone, similar to nonusers with mean intakes in some age/sex groups below the Recommended Daily Allowance (RDA)/Adequate Intake (AI) for iron, calcium, and folate. Multivitamin users had mean intakes (from diet plus supplement) of folate above the RDA and iron intakes also increased to RDA levels among women aged 19 to 50 years. Calcium supplement users had lower calcium and vitamin D intakes than nonusers from diet alone in some age/sex groups. Calcium tablets increased mean calcium intakes to AI levels among all age/sex groups. Many supplement users exceeded the new Upper Limits of safe intake; 47% in the case of niacin. APPLICATIONS Supplements are commonly used and can help some persons adhere to Dietary Reference Intake recommendations concerning intake of folate, calcium, vitamin D. and iron. We found multivitamin users to have higher total intakes of folic acid, iron, calcium, and vitamin D. Also, targeted use of calcium supplements effectively enhanced intakes. However, concurrent vitamin D supplementation is important and awareness of product composition with respect to Upper Limits is essential.

Beliefs, Attitudes, and Practices of Breastfeeding Mothers From a Periurban Community in South Africa

The aim of this study was to document the breastfeeding practices, beliefs, and attitudes of periurban South African lactating mothers with infants younger than 6 months. None of the mothers (n = 115, mean age 26 ± 6.3 years) reported exclusively breastfeeding their infants, with complementary breastfeeding being the most practiced (78%) feeding mode. Complementary foods were fed to 32% of infants by their first month of life. Perceived inadequate production of breast milk was the most common (90%) reason cited for adding foods and liquids to breastfeeds. Mothers valued use of traditional herbal preparations (muthi), with more then half (56%) of the infants having received their first dose of muthi before 1 month of age. Our study provides important data on breastfeeding practices of women living within resource-poor settings. Development of successful infant-feeding interventions aimed at promoting overall infant health can benefit from knowledge of these breastfeeding patterns.

Chinanteco Management of Aechmea magdalenae: Implications for the Use of TEK and TRM in Management Plans1

The importance of incorporating traditional ecological knowledge (TEK) and traditional resource management (TRM) into resource management plans is increasingly recognized, but little quantitative data exists on the ecological and economic implications of these systems. We quantitatively evaluate the TEK and TRM associated with the nontimber forest species, Aechmea magdalenae, in indigenous Chinanteco communities in Mexico. Two TRM systems forA. magdalenae are described and their effects on growth rates of individuals and populations are measured. Simulations using matrix population models combined with yield experiments reveal that one management system is higher yielding and less costly than the other. Thinning and transplanting are two of the most important management practices that enable populations to withstand higher rates of harvest than those predicted in a management plan that was not based on TRM. Quantitative evaluation of Chinanteco TEK is used to discuss how it may be best combined with science in management plans for nontimber forest species.ResumenEl reconocimiento de la importancia de incorporar el conocimiento ecologico tradicional (CET) y el manejo tradicional de recursos (MTR) en planes de manejo de recursos naturales ha venido creciendo, pero aún existe poca información cuántitativa sobre las implicaciones económicas y ecológicas de estas sistemas. Se cuantificaron el CETy el MTR asociado con una especie no maderable, Aechmea magdalenae, en comunidades indígenas chinantecas en México. Se describieron dos sistemas chinantecos de manejo de A. magdalenae, y se midieron sus efectos sobre el crecimiento de individuos y de poblaciones. Simulaciones con modelos matriciales, combinados con experimentos de rendimiento mostraron que uno de los sistemas rendía más y a menor costo que el otro. El aclareo y el transplante fueron de las técnicas de manejo más importantes, mismas que permitieron que las poblaciones soportaran una intensidád de cosecha más alta que lo previsto por un plan de manejo previo. La evaluación cuantitativa del CET chinanteco es usada para reflexionar sobre como este podría ser combinado de mejor manera con la ciencia para la elaboración de planes de manejo de especies no maderables.

Risk factors for iron deficiency anaemia in preschool children in northern Ethiopia

OBJECTIVE To determine risk factors for anaemia in preschool children. DESIGN A cross-sectional study. SETTING Tigray province, northern Ethiopia. SUBJECTS 2080 of 2373 children aged 6-60 months provided blood to assess anaemia. RESULTS Anaemia was highly prevalent (42%) and constituted an important nutritional problem in the region. In a sub-sample of 230 anaemic children, 56% had a low red blood cell (RBC) count, and 43% had a serum ferritin of less than 12 microgl(-1) indicating that the anaemia was largely due to iron deficiency. Unlike other regions in developing countries, hookworm (0.4%) and malaria (0.0%) were rare and contributed little to the anaemia. Even though their diet lacked variety, the amount of iron consumed through cereal-based staple foods was adequate. However, the iron in these foods was not readily available and their diets were probably high in iron absorption inhibitors and low in enhancers. Dietary factors associated with anaemia included frequent consumption of inhibitors, such as fenugreek and coffee, and poor health in the child such as diarrhoea and stunting. CONCLUSIONS Underlying causes of anaemia were lack of safe water and inadequate human waste management, maternal illiteracy and mother being ill, and having no food reserves. The root cause of these factors was poverty. The optimal control strategy for iron deficiency anaemia should have a holistic approach which includes the alleviation of poverty, the empowerment of women and the provision of a safe environment.