Green Leafy Vegetables of Rural India: Ethnobotany and Contribution To
Total Page:16
File Type:pdf, Size:1020Kb
Green Leafy Vegetables of Rural India: Ethnobotany and Contribution to Eye Health Julie Bélanger Degree of Doctor of Philosophy Plant Science Department, Faculty of Agricultural and Environmental Sciences McGill University Montreal, Quebec, Canada May 2010 A thesis submitted to McGill University in partial fulfillment of the requirements of the degree of Doctor of Philosophy ©Julie Bélanger 2010. Library and Archives Bibliothèque et Canada Archives Canada Published Heritage Direction du Branch Patrimoine de l’édition 395 Wellington Street 395, rue Wellington Ottawa ON K1A 0N4 Ottawa ON K1A 0N4 Canada Canada Your file Votre référence ISBN: 978-0-494-68507-5 Our file Notre référence ISBN:978-0-494-68507-5 NOTICE: AVIS: The author has granted a non- L’auteur a accordé une licence non exclusive exclusive license allowing Library and permettant à la Bibliothèque et Archives Archives Canada to reproduce, Canada de reproduire, publier, archiver, publish, archive, preserve, conserve, sauvegarder, conserver, transmettre au public communicate to the public by par télécommunication ou par l’Internet, prêter, telecommunication or on the Internet, distribuer et vendre des thèses partout dans le loan, distribute and sell theses monde, à des fins commerciales ou autres, sur worldwide, for commercial or non- support microforme, papier, électronique et/ou commercial purposes, in microform, autres formats. paper, electronic and/or any other formats. The author retains copyright L’auteur conserve la propriété du droit d’auteur ownership and moral rights in this et des droits moraux qui protège cette thèse. Ni thesis. Neither the thesis nor la thèse ni des extraits substantiels de celle-ci substantial extracts from it may be ne doivent être imprimés ou autrement printed or otherwise reproduced reproduits sans son autorisation. without the author’s permission. In compliance with the Canadian Conformément à la loi canadienne sur la Privacy Act some supporting forms protection de la vie privée, quelques may have been removed from this formulaires secondaires ont été enlevés de thesis. cette thèse. While these forms may be included Bien que ces formulaires aient inclus dans in the document page count, their la pagination, il n’y aura aucun contenu removal does not represent any loss manquant. of content from the thesis. DEDICATION This dissertation is dedicated to the women of Madanapalle, who generously gave their time and shared with us their knowledge of the plants they use and value. i ABSTRACT Recognition of the contribution of biological diversity to human health demands more scientifically sound evidence than currently exists, while the multifactorial nature of this relationship calls for innovative research frameworks. This thesis presents a multidisciplinary case study on the contribution of elements of biological diversity, namely wild and cultivated leafy vegetables, towards age-related cataract prevention in a rural developing country context. At the center of this thesis, an ethnobotanical study identified determinants of consumption of leafy vegetables and demonstrated how perceived properties and cultivation status significantly influence consumption patterns. Plant species of interest, analysed by High Performance Liquid Chromatography, were found to exhibit high concentrations of lutein and β-carotene. Drawing on ethnobotanical and analytical data, an eye hospital-based case-control study was conducted to compare leafy vegetable consumption and diversity, along with lutein and zeaxanthin intake, in female patients identified with and without age-related cataract. Conflicting results for associations between leafy vegetable species and age-related cataract, and protective associations for elements of traditional diets, including yogurt and tea, were observed. The integration of results across isolated studies in a multidisciplinary framework further ii reflected the complex biological, socio-economic and environmental components of eye health and leafy vegetable diversity, and highlighted new knowledge with important application in the eye health of populations at risk. iii RÉSUMÉ Afin de reconnaître la contribution de la biodiversité à la santé humaine, de solides preuves scientifiques additionnelles sont requises. D’autre part, la nature multifactorielle de cette relation nécessite l’élaboration de cadres de recherche innovateurs. Ce mémoire présente une étude de cas multidisciplinaire sur la contribution d’éléments de la biodiversité, en particulier les légumes feuillus cultivés et sauvages, en relation avec la prévention de la cataracte liée à l’âge dans le contexte rural de l’Inde du Sud. Au coeur de ce projet, une étude ethnobotanique a permis d’identifier les facteurs déterminant la consommation de légumes feuillus, et de démontrer l’influence significative des propriétés qui leur sont attribuées et de leur statut de culture sur les habitudes de consommation. Les espèces analysées par chromatographie en phase liquide à haute performance ont affiché d’importantes concentrations de lutéine et de β-carotène. Se basant sur ces données ethnobotaniques et analytiques, une étude cas témoin a été conduite dans un centre d’ophtalmologie afin de comparer la consommation de légumes feuillus, en quantité et en diversité, et de lutéine et zéaxanthine, chez des patientes diagnostiquées et des témoins sains. Des associations contradictoires concernant la consommation de légumes feuillus et le risque de cataracte ont été observées. En revanche, certains aliments traditionnels, iv comme le yaourt et le thé, ont démontré une association négative avec la cataracte. L’intégration de ces études à l’intérieur d’un cadre multidisciplinaire a permis de tenir compte des relations complexes entre les composantes biologiques, socio-économiques et environnementales de la santé de l’oeil et de la diversité botanique, permettant ainsi la découverte d’importantes connaissances applicables à la prévention de la cataracte chez des populations à risque. v ACKNOWLEDGEMENTS My first word of thank is to my supervisor, Professor Timothy Johns, for his precious advices and constant positive and encouraging support. Professor Johns is an exceptional mentor, and his deep involvement in his research on the conservation of indigenous food and health systems and environment, is truly inspiring. I also express profound gratitude to Dr. Shoba Katumalla without whom this complex project would never have been possible. We conducted the study in the world-class eye hospital she herself established, and she personally examined each participant of this study. Her professionalism, dedication and sincere desire to make a difference by helping people in need were for me very influential examples. I would like to thank the numerous participants of this study who gave their time and shared their knowledge with us in the course of this study. I am very thankful to my two research assistants, Hymavathi Kalimidi and Girija Rani, for commitment and attention to detail in their work, and above all for their friendship and introducing me to their culture. Also, I am indebted to the Siloam Eye Hospital staff for their extensive technical and logistic support throughout this adventure, especially Mr. Anand and Ms. Salome. vi The carotenoid analysis was made possible thanks to Dr. P. Sudhakar, and Dr. R. K. Reddy of the Acharya Ranga Reddy Agricultural Research Station (Tirupati). I would like to thank Mungara Balakrishna for technical and logistic support, as well as for advices, friendship and patience. Many thanks also go to Dr. Latha, Mr. Sreenu and the other members of the Plant Physiology Laboratory. Thanks to the invitation of Dr. Rodriguez-Amaya and the supervision of her graduate students, I acquired skills and knowledge of the analysis of carotenoids in foods. The advices and logistic help from Dr. P. Nirmalan, Dr. M. Aruna and Mrs. Salome Yesudas were invaluable in finding appropriate contacts and research location. I am grateful to my advisory committee members, Dr. Jacqueline Bede, Dr. Alan Watson, and to Dr. Grace Egeland and Dr. Grace Marquis for providing constructive criticism. Dr. Jose Correa of the McGill Statistical Consulting Service gracefully provided advices for statistical analysis. I also express gratitude to Louise Johnson-Down for advices on dietary data and methodology to estimate intakes. I thank many people for useful discussions, and ought to mention my colleagues Dr. Patrick Owen and Bronwen Powell. My gratitude also goes to the secretaries of the Plant Science Department, Mrs. Carolyn Bowes and Mrs. Roslyn James. vii I acknowledge the International Development Research Center (IDRC), Fonds Québécois de la Recherche sur la Nature et les Technologies (FQRNT), and Natural Sciences and Engineering Research Council (NSERC) for providing funding through graduate scholarships. I also thank McGill University for funding through Graduate Studies Fellowship and Recruitment Excellence Fellowship. Last but not least, my gratitude goes to my family and friends for their continuous encouragements, and my deepest gratitude goes to my partner François for infinite patience, support and motivation throughout my studies. viii TABLE OF CONTENTS DEDICATION………………………………………….………………………..i ABSTRACT……….……………………………………………………………..ii RÉSUMÉ.………………………………………………………………………..iv ACKNOWLEDGEMENTS.…………………………………………………...vi TABLE OF CONTENTS .................................................................................ix LIST OF TABLES ...........................................................................................xv