The Health Benefits of Traditional Chinese Plant Medicines: Weighing the scientific evidence A report for the Rural Industries Research and Development Corporation by Graeme E. Thomson February 2007 RIRDC Publication No 06/128 RIRDC Project No DAV-227A © 2007 Rural Industries Research and Development Corporation. All rights reserved. ISBN 1 74151 391 X ISSN 1440-6845 The Health Benefits of Traditional Chinese Plant Medicines: Weighing the scienfitic evidence Publication No. 06/128 Project No.DAV-227A The information contained in this publication is intended for general use to assist public knowledge and discussion and to help improve the development of sustainable industries. The information should not be relied upon for the purpose of a particular matter. Specialist and/or appropriate legal advice should be obtained before any action or decision is taken on the basis of any material in this document. The Commonwealth of Australia, Rural Industries Research and Development Corporation, the authors or contributors do not assume liability of any kind whatsoever resulting from any person's use or reliance upon the content of this document. This publication is copyright. However, RIRDC encourages wide dissemination of its research, providing the Corporation is clearly acknowledged. For any other enquiries concerning reproduction, contact the Publications Manager on phone 02 6272 3186. Researcher Contact Details Graeme Thomson Department of Primary Industries, Victoria 621 Burwood Highway, Knoxfield Phone: 03 9210 9222 Fax: 03 9800 3521 Email: [email protected] In submitting this report, the researcher has agreed to RIRDC publishing this material in its edited form. RIRDC Contact Details Rural Industries Research and Development Corporation Level 2, 15 National Circuit BARTON ACT 2600 PO Box 4776 KINGSTON ACT 2604 Phone: 02 6272 4819 Fax: 02 6272 5877 Email: [email protected]. Web: http://www.rirdc.gov.au Published in February 2007 Printed on environmentally friendly paper by Canprint ii Foreword Over the past decade, the Rural Industries Research and Development Corporation has strongly supported research focussed on ‘Asian foods’ and ‘new plant products’. Within these programs, Asian vegetables and to a lesser extent, medicinal herbs, have been of major interest. It seems logical then that this new report should amalgamate some of this existing knowledge and explore new opportunities in Chinese medicinal plants. Plants were originally the basis of all human health care and Chinese traditional medicine has used hundreds of species for over 2,000 years. In addition to their potential to alleviate chronic disease in Australia, medicinal herbs offer us more opportunities than most horticultural crops in their potential for development as value-added products. This report explores options for new medicinal plants through an examination of evidence-based medical efficacy. RIRDC invests in new and emerging industries on behalf of government and industry stakeholders. New industries provide opportunities to be captured by investors and rural producers, and provide avenues for farmers to manage change and diversify. The establishment of new industries contributes to regional development and community resilience. This project was funded from RIRDC Core Funds (which are provided by the Australian Government) and by the Department of Primary Industries, Victoria. This report, an addition to RIRDC’s diverse range of over 1600 research publications, forms part of our Asian Foods R&D program, which aims to foster new Australian industries producing innovative, high quality foods and consumable products with Asian origins. Most of our publications are available for viewing, downloading or purchasing online through our website: • downloads at www.rirdc.gov.au/fullreports/index.html • purchases at www.rirdc.gov.au/eshop Peter O’Brien Managing Director Rural Industries Research and Development Corporation iii Acknowledgments Jingye Zhang, Slobodan Vujovic, Murat Top, Jane Parker iv Contents Foreword............................................................................................................................................... iii Acknowledgments................................................................................................................................. iv Executive Summary ............................................................................................................................. vi 1. Introduction & Objectives................................................................................................................ 1 2. Methodology ...................................................................................................................................... 4 Species review - boundaries of the investigation .................................................................................4 The search ............................................................................................................................................4 What constitutes good evidence ? ........................................................................................................5 3. Results ................................................................................................................................................ 8 General observations ............................................................................................................................8 4. Species review .................................................................................................................................. 10 5. Discussion....................................................................................................................................... 134 v Executive Summary What the report is about There is growing public utilisation of complementary medicines in Australia, of which herbal medicines are a major component. The projected value of the global herbal medicine industry is expected to reach $USD 5 trillion annually by the year 2050. As part of the process for Australian producers to benefit from this developing industry, a clear picture of the current Australian industry is required so that a strategic approach can be developed. This project provides an important source of information for current and future industry investors and is designed to fill a knowledge gap on the current status of research and make recommendations for future research. The aim has been to critically examine the all the current science-based medical evidence supporting the use of Chinese medicinal plants. It has been designed to present results from a comprehensive, up-to-date literature review. This review targeted those Chinese medicinal plant species that have been documented to possess curative, preventive or palliative functions relevant to important chronic ailments in Australia. The study predominantly focussed on plants used in Chinese medicine and on plants with their genetic origins in Asia. Asian plants used in non-Chinese folk medicine were sometimes included when relevant. Who is the report targeted at? This report is aimed at growers, researchers and investors as a reference of supporting science-based medical evidence on a range of medicinal plants. Background Plants have always been a source of medicine and a major resource for human health care. Chinese traditional medicine has documented the use of botanicals for over 2,000 years. Natural products and mainly plants (greater than 80%) are the basis of traditional Chinese medicine. About 500 species are commonly prescribed by Chinese medical practitioners but up to 2,000 plants have a history of recorded use. The scientific study of substances used medicinally by different ethnic or cultural groups is viewed by researchers as an increasingly relevant and important source of new medicinal products. Chinese medicinal herbals make up a large proportion of the over US$15 billion annual worldwide sales of natural medicines. Chinese medicines have been developed to treat all important diseases including chronic ailments. In Australia the most important of these include coronary heart disease, stroke, cancer, diabetes, arthritis, dementia and respiratory disease (including asthma). Total health expenditure (around 10% of gross domestic product) is an increasing burden on the Australian economy and one that continues to increase with pressure from an ageing population. Studies show that 60% of Australian consumers have spent some of their health dollars on supplements and natural remedies. In 2004, Australians spent AU$1.8 billion on complementary medicines and therapies. There is a willingness to believe that some of these ‘alternative remedies’ may be effective options to mainstream Western treatments. Methods used All the screened literature pertaining to human health effects was science-based and published either in recognised science and medical journals, or review text books. Scientific and medical data were primarily sourced from the PubMed electronic database which also covers relevant Chinese journals. Results from human trials were given most weight in evaluation. The study considered around 500 Asian medicinal plant species and directly reviewed and documented information on over 400 with links to some of Australia’s chronic diseases. Ninety-eight percent of these were higher plants (ie. angiosperms and gymnosperms). Over 3,500 scientific reference items were reviewed and over 1,000 of these