Teas, Cocoa and Coffee

In recent years, the role of plant secondary metabolites as protective constituents in the human diet has been a growing area of research. Unlike the traditional vitamins, they are not essential for short-term wellbeing, but there is increasing evidence that modest long-term intakes can have favourable impacts on the incidence of cancers and many chronic diseases, including cardiovascular disease and type II diabetes, which are occurring in Western populations with increasing frequency.This book covers the latest science on the metabolism and potential health benefits of teas, cocoa, coffee and their extracts in the human diet. From an opening chapter tracing the origins of teas, cocoa and coffee as beverage, the book proceeds to explore the phytochemical content of coffee, cocoa and the various types of tea. The bioavailability of secondary metabolites from each of the beverages is then considered in depth, and related directly to their health benefits. Embracing the full range of tea, coffee and cocoa beverages and products, the book offers the most up-to-date and comprehensive treatment of these increasingly important dietary components.As the only book to bring together the latest information on the biochemistry and health benefits of teas, coffee and cocoa, this book is essential reading for food scientists and technologists involved in the production of tea, coffee and cocoa products. Nutritionists will value the book's health focus, while agricultural scientists working on the cultivation of these crops will prize its scope and depth of detail. It is also an important resource for all those who use functional ingredients in other products, whether they are based in industry or research.

Contributors ix1 The Origins of Tea, Coffee and Cocoa as Beverages 1Timothy J. Bond1.1 Introduction 11.2 The beverages in question 11.3 Discoveries - myth and legend 21.3.1 Tea 31.3.2 Coffee 41.3.3 Cacao products 51.4 Global domination begins 81.4.1 Tea - overland and a race by sea 91.4.2 Coffee - from persecution to epitomising the protestant work ethic 131.4.3 Chocolate - from lying down . . . to sitting up 141.5 From foreign fancies to the drinks of the masses 151.6 Tea, coffee and chocolate 'go public' 181.7 Opinion is divided on the merits of the three beverages 191.8 Tea, coffee and chocolate - the future 22References 222 Purine Alkaloids: A Focus on Caffeine and Related Compounds in Beverages 25Michael E.J. Lean, Hiroshi Ashihara, Michael N. Clifford and Alan Crozier2.1 Introduction 252.2 Occurrence of purine alkaloids 262.3 Biosynthesis of purine alkaloids 272.4 Degradation of purine alkaloids 272.5 Decaffeinated tea and coffee 292.6 Metabolism of caffeine by humans 312.7 Effects of caffeine consumption on human health 332.7.1 Biochemical and biological actions of caffeine 342.7.2 Mental performance enhancement 372.7.3 Physical performance enhancement 372.7.4 Caffeine toxicity 382.7.5 Tolerance, withdrawal and dependence 392.7.6 Caffeine in pregnancy 392.7.7 Toxicity in other species 402.8 Summary 40References 403 Phytochemicals in Teas and Tisanes and Their Bioavailability 45Michael N. Clifford and Alan Crozier3.1 Introduction 453.2 Phytochemical content of teas and tisanes 453.2.1 Camellia teas 453.2.2 Yerba mat¿e tea 543.2.3 Itadori tea 583.2.4 Rooibos tea 593.2.5 Honeybush tea 593.2.6 Chamomile tea 623.2.7 Hibiscus tea 623.2.8 Fennel tea 633.2.9 Anastatica tea 633.2.10 Ficus tea 663.3 Bioavailability - absorption, distribution, metabolism and excretion 663.3.1 Green tea 683.3.2 Black tea 773.3.3 Itadori tea 803.3.4 Rooibos tea 813.3.5 Honeybush tea 843.3.6 Hibiscus tea 853.3.7 Fennel tea 853.3.8 Other teas 873.4 Summary 87References 884 Teas, Tisanes and Health 99Diane L. McKay, Marshall G. Miller and Jeffrey B. Blumberg4.1 Introduction 994.2 Black, oolong and green tea (C. sinensis) 1004.2.1 Black tea 1004.2.2 Oolong tea 1074.2.3 Green tea 1094.3 Other teas and tisanes 1164.3.1 Yerba mat¿e (Ilex paraguariensis) 1164.3.2 Itadori (Polygonum cuspidatum) 1184.3.3 Chamomile (Chamomilla recutita L.) 1194.3.4 Hibiscus (Hibiscus sabdariffa L.) 1204.3.5 Rooibos (Aspalathus linearis) 1264.3.6 Honeybush (Cyclopia intermedia) 1284.4 Summary and conclusions 130References 1315 Phytochemicals in Coffee and the Bioavailability of Chlorogenic Acids 143Angelique Stalmach, Michael N. Clifford, Gary Williamson and Alan Crozier5.1 Introduction 1435.2 Harvesting coffee beans, roasting and blending 1445.3 Phytochemicals in coffee 1445.3.1 Effects of roasting on the phytochemical content of coffee beans 1495.3.2 Chlorogenic acid intake and coffee consumption 1545.4 Bioavailability of coffee chlorogenic acids in humans 1555.4.1 Studies involving volunteers with and without a functioning colon 1565.5 Conclusions 164References 1646 Coffee and Health 169Gary Williamson6.1 Introduction 1696.2 Antioxidant status 1706.2.1 Effect of coffee consumption on antioxidant status: epidemiological and cohort studies 1796.2.2 Effect of coffee consumption on antioxidant status: intervention studies 1796.3 Diabetes 1806.3.1 Effect of coffee consumption on diabetes risk: epidemiological and cohort studies 1806.3.2 Effect of coffee consumption on diabetes risk: intervention studies 1826.4 Cardiovascular disease 1836.4.1 Effect of coffee consumption on cardiovascular risk: epidemiological and cohort studies 1836.4.2 Effect of coffee consumption on cardiovascular risk: intervention studies 1846.5 Effect of coffee on inflammation 1866.6 Effect of coffee consumption on cancer risk 1866.6.1 Effect of coffee consumption on cancer risk: epidemiological and cohort studies 1866.6.2 Effect of coffee consumption on cancer risk: intervention studies 1886.7 Summary 188References 1887 Phytochemicals in Cocoa and Flavan-3-ol Bioavailability 193Francisco Tomas-Barberan, Gina Borges and Alan Crozier7.1 Introduction 1937.2 Phytochemicals in cocoa 1947.2.1 Purine alkaloids, theobromine and caffeine 1947.2.2 Flavan-3-ols 1947.2.3 Phenolic acid derivatives 1967.2.4 Minor phytochemicals 1977.3 Bioavailability of cocoa flavan-3-ols 1987.3.1 Background 1987.3.2 Flavan-3-ol monomers 2007.3.3 Procyanidins 2107.4 Conclusions 212References 2138 Cocoa and Health 219Jennifer L. Donovan, Kelly A. Holes-Lewis, Kenneth D. Chavin and Brent M. Egan8.1 Introduction 2198.2 Composition of cocoa products 2208.3 Worldwide consumption of cocoa and its contribution to flavonoid intake 2228.4 Epidemiological and ecological studies of cocoa 2228.5 Cocoa effects on vascular endothelial function and platelet activity 2248.6 Cocoa and hypertension 2278.7 Antioxidant and anti-inflammatory effects of cocoa 2298.8 Effects of cocoa consumption on lipid and lipoprotein metabolism 2328.9 Cocoa effects on insulin sensitivity 2338.10 Cocoa effects on cerebral blood flow and neurocognitive functioning 2348.11 Potential negative health effects of cocoa consumption 2378.11.1 Obesity 2378.11.2 Testicular health 2378.11.3 Acne 2388.11.4 Dental caries 2388.12 Effects of consumption of cocoa with milk or other foods 2388.13 Conclusions 239References 240Index 247A color plate section falls between pages 6 and 7