Green Tea Polyphenols: Nutraceuticals of Modern Life edited by Lekh R. Juneja, Mahendra P. Kapoor, Tsutomu Okubo, and Theertham P. Rao. Boca Raton, FL: CRC Press; 2013. Hardcover, 335 pages. ISBN 978-1-4398-4788-6. $129.95.
This attractively presented, concise monograph on a well-known functional food and nutraceutical discusses green tea (Camellia sinensis, Theaceae) research over 16 chapters of fully indexed text. The chapters are written by global experts who are recognized researchers in the study of green tea.
The book cover shows green tea leaves steeped in water in a teacup, and the editors attempt to cover the in vitro and in vivo research supporting the health benefits of this very popular beverage. Each chapter presents a specific scientific theme, highlighting some of the available research studies up to 2011.
The book begins with a nod to the history and processing of green tea. Although the authors recognize that modern green tea production in China accounts for the largest volumes, the introductory comments do not reflect on ancient traditions of green tea’s health benefits in that country.
Subsequent chapters describe in detail, with accompanying figures of the various chemical structures, the chemical composition of tea varieties, and the bioactive catechin structures. The chapters on metabolism, bioavailability, and safety are well-written. The writing highlights the short half-life and low bioavailability of the key polyphenol — the catechin EGCG — in the body upon ingestion of tea or an extract. Several chapters explore the current research on nanoparticulate preparations, which may affect changes in the absorption properties of the catechins.
The meat of the book is devoted to the biological and health properties of green tea and is presented in chapters four through 14. These deal with the numerous health benefits associated with consumption of green tea polyphenols and, in particular, their relationship to cancer risk and prevention. Although these chapters are quite comprehensive and numerous biological mechanisms of action are covered, it was surprising to find an absence of any reference to the numerous published studies by Morre et al. relating to the inhibition of ENOX2 (NADH oxidase) by the catechins at nanomolar potency. Morre has presented compelling data that the anti-tumor effects of the catechins can be explained by this reduction-oxidation mechanism.
The book could have discussed in more detail the first botanical drug to receive approval by the US Food and Drug Administration, a green tea extract known as Veregen® (MediGene AG; Planegg/Martinsried, Germany) for the topical treatment of genital warts. Furthermore, this preparation now is being used in clinical trials to examine its antiviral effects in participants with HIV. Additionally, absent in these chapters is a discussion on whether the effects of various combinations of the green tea catechins can offer synergistic effects.
There are detailed chapters reviewing studies on cardiovascular disease, bone and muscle health, allergies, oral care, inflammation, and gut health. The final chapters address the nutrigenomics and proteomics of green tea polyphenols and then examine food and nonfood applications such as supplements and skin and hair cosmetic products.
In conclusion, this book provides a welcome addition to the research on green tea and highlights the importance of linking biological activity to a chemical at a measurable concentration. This information is invaluable in order to prepare an appropriate dose regimen for clinical study. Published studies on green tea continue to explode in frequency, and within a short time it is hoped there will be a second edition of this book.
—Raymond Cooper, PhD
Department of Applied Biology and Chemical Technology
The Hong Kong Polytechnic University Hong Kong, China