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Theodoridis X, Chourdakis M, Papaemmanouil A, Chaloulakou S, Papageorgiou N, Georgakou AV, Chatzis G, Triantafyllou A. The Association between Food Groups, Nutraceuticals, and Food Supplements Consumption on Vascular Health Outcomes: A Literature Review. Life (Basel) 2024; 14:1210. [PMID: 39337992 PMCID: PMC11433244 DOI: 10.3390/life14091210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2024] [Revised: 08/29/2024] [Accepted: 09/13/2024] [Indexed: 09/30/2024] Open
Abstract
Vascular aging, marked by alterations in the structure and function of blood vessels, including heightened arterial stiffness and impaired endothelial function, is linked to a higher likelihood of developing cardiovascular and age-associated pathological conditions. Oxidative stress and inflammation are key stimulation factors in vascular aging. Engaging in healthy dietary habits could enhance the functioning of blood vessels. The aim of this study was to conduct a literature review of the evidence regarding the relationship between food regimens, nutraceuticals, and dietary supplements and vascular health. A search of electronic databases, including PubMed, Scopus, and Web of Science Core Collection, was performed. Experimental and observational studies evaluating the association between food groups, nutraceuticals, supplements, and endothelial function and/or arterial stiffness were deemed eligible for this narrative review. Based on the current body of the included studies, food groups, nutraceuticals, and dietary supplements may not demonstrate superiority over placebos in enhancing markers of vascular health. To obtain more reliable evidence on the effectiveness of interventions in vascular health, additional RCTs with larger sample sizes, extended follow-up periods, and multi-center participation are necessary. Enhancing the credibility of these RCTs requires better control of dietary variables and more precise measurement of vascular health markers.
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Affiliation(s)
- Xenophon Theodoridis
- Laboratory of Hygiene, Social and Preventive Medicine and Medical Statistics, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, University Campus, 54124 Thessaloniki, Greece; (X.T.); (A.P.); (S.C.); (N.P.); (A.V.G.)
- Third Department of Internal Medicine, Papageorgiou Hospital, Aristotle University of Thessaloniki, 56429 Thessaloniki, Greece
| | - Michail Chourdakis
- Laboratory of Hygiene, Social and Preventive Medicine and Medical Statistics, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, University Campus, 54124 Thessaloniki, Greece; (X.T.); (A.P.); (S.C.); (N.P.); (A.V.G.)
| | - Androniki Papaemmanouil
- Laboratory of Hygiene, Social and Preventive Medicine and Medical Statistics, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, University Campus, 54124 Thessaloniki, Greece; (X.T.); (A.P.); (S.C.); (N.P.); (A.V.G.)
| | - Stavroula Chaloulakou
- Laboratory of Hygiene, Social and Preventive Medicine and Medical Statistics, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, University Campus, 54124 Thessaloniki, Greece; (X.T.); (A.P.); (S.C.); (N.P.); (A.V.G.)
| | - Niki Papageorgiou
- Laboratory of Hygiene, Social and Preventive Medicine and Medical Statistics, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, University Campus, 54124 Thessaloniki, Greece; (X.T.); (A.P.); (S.C.); (N.P.); (A.V.G.)
| | - Athina Vasiliki Georgakou
- Laboratory of Hygiene, Social and Preventive Medicine and Medical Statistics, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, University Campus, 54124 Thessaloniki, Greece; (X.T.); (A.P.); (S.C.); (N.P.); (A.V.G.)
| | - Georgios Chatzis
- School of Physical Education and Sports Science, Aristotle University of Thessaloniki, 57001 Thessaloniki, Greece;
| | - Areti Triantafyllou
- Third Department of Internal Medicine, Papageorgiou Hospital, Aristotle University of Thessaloniki, 56429 Thessaloniki, Greece
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Álvarez-Bustos A, Carnicero JA, Rodríguez-Sánchez B, El-Assar M, Rueda R, Pereira SL, Sepúlveda-Loyola W, Garcia-Garcia FJ, Sulo S, Rodríguez-Mañas L. Association Between Pulse Wave Velocity and Frailty, Disability, and Mortality in Community-Dwelling Older Adults. JACC. ADVANCES 2023; 2:100423. [PMID: 38939008 PMCID: PMC11198582 DOI: 10.1016/j.jacadv.2023.100423] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 04/17/2023] [Accepted: 05/09/2023] [Indexed: 06/29/2024]
Abstract
Background Arterial stiffness leads to several adverse events in the older population, but there is a lack of data on its association with frailty, disability, and mortality in the same population. Objectives The purpose of this study was to evaluate the role of arterial stiffness in the loss of functional ability (frailty and disability) and mortality. Methods Data were taken from community-dwelling aged 65 years participants without diabetes in the Toledo Study of Healthy Ageing cohort. Pulse wave velocity (PWV), assessed through SphygmoCor, was recorded at baseline. Median follow-up time were 2.99 years for frailty (frailty phenotype [FP] and Frailty Trait Scale-5 [FTS5]) and disability (Katz Index) and 6.2 for mortality. Logistic regressions models were built for disability and frailty and Cox proportional hazards model for death, adjusted by age and sex, comorbidity, cardiovascular risk factors, asymmetric dimethylarginine levels, and polypharmacy. Results Overall, 978 (mean age 74.5 ± 5.6 years, 56.7% female) participants were included. Different cut-off points were shown for each outcome. PWV >11.5 m/s was cross-sectionally associated with frailty (FP: OR fully-adjusted model: 1.69, 95% CI: 1.45-1.97; FTS5: OR: 1.51, 95% CI: 1.22-1.87) and disability (OR: 1.51, 95% CI: 1.26-1.79); PWV >10 m/s with incident frailty by FP (OR: 1.36, 95% CI: 1.10-1.68) and FTS5 (OR: 1.40, 95% CI: 1.12-1.75), and PWV >11 m/s with death (HR: 1.28, 95% CI: 1.09-1.50). For incident (OR: 1.28, 95% CI: 1.06-1.55) and worsening disability (OR: 1.21, 95% CI: 1.02-1.45) the threshold was 12.5 m/s. Below these cut-off points, age was the best predictor of adverse outcomes. Conclusions Arterial stiffness predicts frailty, disability, and mortality in older people, with different cut-off points, ie,severity degrees, for each of the assessed outcomes.
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Affiliation(s)
- Alejandro Álvarez-Bustos
- Centro de Investigación Biomédica en Red sobre Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | - Jose A. Carnicero
- Centro de Investigación Biomédica en Red sobre Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
- Fundación de Investigación Biomédica, Hospital Universitario de Getafe, Getafe, Spain
| | - Beatriz Rodríguez-Sánchez
- Centro de Investigación Biomédica en Red sobre Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
- Departamento de Economía Aplicada, Economía Pública y Economía Política, Facultad de Derecho, Universidad Complutense de Madrid, Madrid, Spain
| | - Mariam El-Assar
- Centro de Investigación Biomédica en Red sobre Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
- Fundación de Investigación Biomédica, Hospital Universitario de Getafe, Getafe, Spain
| | | | | | | | - Francisco J. Garcia-Garcia
- Centro de Investigación Biomédica en Red sobre Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
- Servicio de Geriatría, Hospital Virgen del Valle, Toledo, Spain
| | - Suela Sulo
- Abbott Nutrition, Chicago, Illinois, USA
| | - Leocadio Rodríguez-Mañas
- Centro de Investigación Biomédica en Red sobre Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
- Servicio de Geriatría, Hospital Universitario de Getafe, Getafe, Spain
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The Potential of Dietary Bioactive Compounds against SARS-CoV-2 and COVID-19-Induced Endothelial Dysfunction. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27051623. [PMID: 35268723 PMCID: PMC8912066 DOI: 10.3390/molecules27051623] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/25/2022] [Accepted: 02/25/2022] [Indexed: 12/24/2022]
Abstract
COVID-19 is an endothelial disease. All the major comorbidities that increase the risk for severe SARS-CoV-2 infection and severe COVID-19 including old age, obesity, diabetes, hypertension, respiratory disease, compromised immune system, coronary artery disease or heart failure are associated with dysfunctional endothelium. Genetics and environmental factors (epigenetics) are major risk factors for endothelial dysfunction. Individuals with metabolic syndrome are at increased risk for severe SARS-CoV-2 infection and poor COVID-19 outcomes and higher risk of mortality. Old age is a non-modifiable risk factor. All other risk factors are modifiable. This review also identifies dietary risk factors for endothelial dysfunction. Potential dietary preventions that address endothelial dysfunction and its sequelae may have an important role in preventing SARS-CoV-2 infection severity and are key factors for future research to address. This review presents some dietary bioactives with demonstrated efficacy against dysfunctional endothelial cells. This review also covers dietary bioactives with efficacy against SARS-CoV-2 infection. Dietary bioactive compounds that prevent endothelial dysfunction and its sequelae, especially in the gastrointestinal tract, will result in more effective prevention of SARS-CoV-2 variant infection severity and are key factors for future food research to address.
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Din USU, Sian TS, Deane CS, Smith K, Gates A, Lund JN, Williams JP, Rueda R, Pereira SL, Atherton PJ, Phillips BE. Green Tea Extract Concurrent with an Oral Nutritional Supplement Acutely Enhances Muscle Microvascular Blood Flow without Altering Leg Glucose Uptake in Healthy Older Adults. Nutrients 2021; 13:nu13113895. [PMID: 34836149 PMCID: PMC8619110 DOI: 10.3390/nu13113895] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/26/2021] [Accepted: 10/28/2021] [Indexed: 01/10/2023] Open
Abstract
Postprandial macro- and microvascular blood flow and metabolic dysfunction manifest with advancing age, so vascular transmuting interventions are desirable. In this randomised, single-blind, placebo-controlled, crossover trial, we investigated the impact of the acute administration of green tea extract (GTE; containing ~500 mg epigallocatechin-3-gallate) versus placebo (CON), alongside an oral nutritional supplement (ONS), on muscle macro- and microvascular, cerebral macrovascular (via ultrasound) and leg glucose/insulin metabolic responses (via arterialised/venous blood samples) in twelve healthy older adults (42% male, 74 ± 1 y). GTE increased m. vastus lateralis microvascular blood volume (MBV) at 180 and 240 min after ONS (baseline: 1.0 vs. 180 min: 1.11 ± 0.02 vs. 240 min: 1.08 ± 0.04, both p < 0.005), with MBV significantly higher than CON at 180 min (p < 0.05). Neither the ONS nor the GTE impacted m. tibialis anterior perfusion (p > 0.05). Leg blood flow and vascular conductance increased, and vascular resistance decreased similarly in both conditions (p < 0.05). Small non-significant increases in brachial artery flow-mediated dilation were observed in the GTE only and middle cerebral artery blood flow did not change in response to GTE or CON (p > 0.05). Glucose uptake increased with the GTE only (0 min: 0.03 ± 0.01 vs. 35 min: 0.11 ± 0.02 mmol/min/leg, p = 0.007); however, glucose area under the curve and insulin kinetics were similar between conditions (p > 0.05). Acute GTE supplementation enhances MBV beyond the effects of an oral mixed meal, but this improved perfusion does not translate to increased leg muscle glucose uptake in healthy older adults.
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Affiliation(s)
- Ushnah S. U. Din
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and National Institute for Health Research Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK; (U.S.U.D.); (T.S.S.); (K.S.); (A.G.); (J.N.L.); (J.P.W.)
| | - Tanvir S. Sian
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and National Institute for Health Research Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK; (U.S.U.D.); (T.S.S.); (K.S.); (A.G.); (J.N.L.); (J.P.W.)
- Department of Surgery and Anaesthetics, Royal Derby Hospital, Derby DE22 3NE, UK
| | - Colleen S. Deane
- Department of Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX1 2LU, UK;
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Ken Smith
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and National Institute for Health Research Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK; (U.S.U.D.); (T.S.S.); (K.S.); (A.G.); (J.N.L.); (J.P.W.)
| | - Amanda Gates
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and National Institute for Health Research Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK; (U.S.U.D.); (T.S.S.); (K.S.); (A.G.); (J.N.L.); (J.P.W.)
| | - Jonathan N. Lund
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and National Institute for Health Research Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK; (U.S.U.D.); (T.S.S.); (K.S.); (A.G.); (J.N.L.); (J.P.W.)
- Department of Surgery and Anaesthetics, Royal Derby Hospital, Derby DE22 3NE, UK
| | - John P. Williams
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and National Institute for Health Research Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK; (U.S.U.D.); (T.S.S.); (K.S.); (A.G.); (J.N.L.); (J.P.W.)
- Department of Surgery and Anaesthetics, Royal Derby Hospital, Derby DE22 3NE, UK
| | - Ricardo Rueda
- Research and Development, Abbott Nutrition, 18004 Granada, Spain;
| | | | - Philip J. Atherton
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and National Institute for Health Research Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK; (U.S.U.D.); (T.S.S.); (K.S.); (A.G.); (J.N.L.); (J.P.W.)
- Correspondence: (P.J.A.); (B.E.P.)
| | - Bethan E. Phillips
- MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and National Institute for Health Research Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Derby DE22 3DT, UK; (U.S.U.D.); (T.S.S.); (K.S.); (A.G.); (J.N.L.); (J.P.W.)
- Correspondence: (P.J.A.); (B.E.P.)
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Landini L, Rebelos E, Honka MJ. Green Tea from the Far East to the Drug Store: Focus on the Beneficial Cardiovascular Effects. Curr Pharm Des 2021; 27:1931-1940. [PMID: 33138757 DOI: 10.2174/1381612826666201102104902] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 10/12/2020] [Indexed: 11/22/2022]
Abstract
Cardiovascular diseases (CVD) are the leading cause of death worldwide. Evidence from observational and randomized controlled studies showing the potential benefits of green tea on lowering CVD risk has been emerging rapidly during the past few decades. These benefits include reduced risk for major cardiovascular events, lowering of blood pressure, decreased LDL cholesterol levels and weight loss. At the same time, the understanding of the physiological mechanisms behind these alterations is advancing. Consumption of green tea originated from China thousands of years ago, but since then, it expanded all over the world. Recent advances in understanding the role of tea polyphenols, mainly catechins, as mediators of tea's health benefits, have caused the emergence of various types of green tea extracts (GTE) on the market. While taking green tea is generally considered safe, there are concerns about the safety of using tea extracts. The present article reviews the current evidence of green tea consumption leading to reduced CVD risk, its potential biological mechanisms and the safety of using GTE.
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Affiliation(s)
- Linda Landini
- S.S.D. Dietetics and Clinical Nutrition ASL 4 Chiavarese Liguria - Sestri Levante Hospital, Sestri Levante GEI, Italy
| | - Eleni Rebelos
- Turku PET Centre, University of Turku, Turku, Finland
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Tea consumption and its effects on primary and secondary prevention of coronary artery disease: Qualitative synthesis of evidence from randomized controlled trials. Clin Nutr ESPEN 2021; 41:77-87. [PMID: 33487310 DOI: 10.1016/j.clnesp.2020.11.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 10/27/2020] [Accepted: 11/10/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND AND AIMS There is a general interest in understanding how the consumption of tea impacts cardiovascular function in individuals at risk of developing cardiovascular disease (CVD). The current review focuses on evidence from randomized controlled trials (RCTs) reporting on associations between tea consumption and endothelial function, in the primary and secondary prevention of coronary artery disease (CAD). METHODS PubMed, EMBASE, and Google Scholar databases/search engines were used to identify eligible studies. Included studies had to report on the impact of tea supplementation of endothelial function or CAD related markers. In addition to flow-mediated dilation (FMD), makers of oxidative stress and inflammation such as oxidized low-density lipoprotein and C-reactive protein were considered as determinants of endothelial function. A total of 34 RCTs met the inclusion criteria, and these reported on the impact of tea consumption on endothelial function in individuals at risk of CVD or patients with CAD. RESULTS The current qualitative synthesis of literature demonstrates that beyond enhancing nitric oxide bioavailability and lowering blood pressure, regular consumption of tea and its active ingredients such as epigallocatechin gallate may be beneficial in reducing markers of oxidative stress and inflammation. Moreover, the reduction of oxidized low-density lipoprotein and C-reactive protein levels, could be a sign of improved endothelial function in individuals at increased risk of developing CVD. CONCLUSIONS The cumulative evidence also suggests that the development of epigallocatechin gallate as a nutraceutical or enriching foods with this bioactive compound could be a feasible strategy to improve endothelial function and lower CVD-risk. However, well-designed RCTs are still necessary to confirm long-term benefits of tea consumption on vascular health.
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Ikeda A, Iso H, Yamagishi K, Iwasaki M, Yamaji T, Miura T, Sawada N, Inoue M, Tsugane S. Plasma tea catechins and risk of cardiovascular disease in middle-aged Japanese subjects: The JPHC study. Atherosclerosis 2018; 277:90-97. [PMID: 30176569 DOI: 10.1016/j.atherosclerosis.2018.08.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 07/03/2018] [Accepted: 08/16/2018] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND AIMS Although a potential benefit of drinking green tea has been suggested to reduce the development of cardiovascular disease, no study has investigated the relationship between plasma tea catechin and risk of cardiovascular disease. METHODS A prospective, nested case-control study was conducted to examine the association between plasma tea catechin and risk of stroke and coronary heart disease (CHD) in a cohort of 29,876 men and women aged 40-69 years without history of heart disease, stroke or cancer. Participants completed a survey and donated blood samples between 1990 and 1994, and were followed-up through 2008. A total of 1132 stroke cases and 209 CHD cases, matched 1:1 to controls (n = 1132) for stroke and 1:2 to controls (n = 418) for CHD, were included in the analysis. RESULTS We found no significant association between plasma tea catechin and the incidence of stroke or CHD in either men or women. However, we found that high plasma levels of epigallocatechin gallate (EGCG) were associated with reduced risk of stroke in non-smoking men; the adjusted odds ratio (95% CI) for the highest vs. non-detectable levels was 0.53 (0.29-0.98). The respective OR in male smokers was 1.23 (0.75-2.16). A significant interaction by smoking status was found for the highest vs. non-detected plasma EGCG in relation to stroke (p-for-interaction: p = 0.09). CONCLUSIONS Plasma tea catechin was not associated with reduced risks of either stroke or CHD, while a protective effect of certain tea catechin on stroke risk is suggested for male non-smokers.
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Affiliation(s)
- Ai Ikeda
- Department of Public Health, Juntendo University School of Medicine, Tokyo, Japan
| | - Hiroyasu Iso
- Public Health, Department of Social Medicine, Osaka University Graduate School of Medicine, Osaka, Japan.
| | - Kazumasa Yamagishi
- Department of Public Health Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Motoki Iwasaki
- Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Tokyo, Japan
| | - Taiki Yamaji
- Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Tokyo, Japan
| | - Tsutomu Miura
- Department of Health and Nutrition, Faculty of Human Life Studies, Jin-ai University, Fukui, Japan
| | - Norie Sawada
- Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Tokyo, Japan
| | - Manami Inoue
- Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Tokyo, Japan
| | - Shoichiro Tsugane
- Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Tokyo, Japan.
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Flavonoids and Their Metabolites: Prevention in Cardiovascular Diseases and Diabetes. Diseases 2017; 5:diseases5030019. [PMID: 32962323 PMCID: PMC5622335 DOI: 10.3390/diseases5030019] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 09/01/2017] [Accepted: 09/03/2017] [Indexed: 12/12/2022] Open
Abstract
The occurrence of atherosclerosis and diabetes is expanding rapidly worldwide. These two metabolic disorders often co-occur, and are part of what is often referred to as the metabolic syndrome. In order to determine future therapies, we propose that molecular mechanisms should be investigated. Once the aetiology of the metabolic syndrome is clear, a nutritional intervention should be assessed. Here we focus on the protective effects of some dietary flavonoids, and their metabolites. Further studies may also pave the way for development of novel drug candidates.
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Azimi S, Mansouri Z, Bakhtiari S, Tennant M, Kruger E, Rajabibazl M, Daraei A. Does green tea consumption improve the salivary antioxidant status of smokers? Arch Oral Biol 2017; 78:1-5. [DOI: 10.1016/j.archoralbio.2017.02.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 02/01/2017] [Accepted: 02/03/2017] [Indexed: 10/20/2022]
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Tea-induced improvement of endothelial function in humans: No role for epigallocatechin gallate (EGCG). Sci Rep 2017; 7:2279. [PMID: 28536463 PMCID: PMC5442103 DOI: 10.1038/s41598-017-02384-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 04/11/2017] [Indexed: 01/16/2023] Open
Abstract
Consumption of tea is inversely associated with cardiovascular diseases. However, the active compound(s) responsible for the protective effects of tea are unknown. Although many favorable cardiovascular effects in vitro are mediated by epigallocatechin gallate (EGCG), its contribution to the beneficial effects of tea in vivo remains unresolved. In a randomised crossover study, a single dose of 200 mg EGCG was applied in three different formulas (as green tea beverage, green tea extract (GTE), and isolated EGCG) to 50 healthy men. Flow-mediated dilation (FMD) and endothelial-independent nitro-mediated dilation (NMD) was measured before and two hours after ingestion. Plasma levels of tea compounds were determined after each intervention and correlated with FMD. FMD significantly improved after consumption of green tea containing 200 mg EGCG (p < 0.01). However, GTE and EGCG had no significant effect on FMD. NMD did not significantly differ between interventions. EGCG plasma levels were highest after administration of EGCG and lowest after consumption of green tea. Plasma levels of caffeine increased after green tea consumption. The results show that EGCG is most likely not involved in improvement of flow-mediated dilation by green tea. Instead, other tea compounds, metabolites or combinations thereof may play a role.
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Singhal K, Raj N, Gupta K, Singh S. Probable benefits of green tea with genetic implications. J Oral Maxillofac Pathol 2017; 21:107-114. [PMID: 28479696 PMCID: PMC5406788 DOI: 10.4103/0973-029x.203758] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 12/22/2016] [Indexed: 11/04/2022] Open
Abstract
Tea is produced from the Camellia sinensis plant and can generally be divided into categories based on how they are processed. In general, green tea that is unfermented C. sinensis has been considered superior to black tea in health benefits. It contains a unique set of catechins that possess biological activity as antioxidant, anti-inflammatory and antiproliferative, which is potentially significant to the prevention and treatment of various forms of diseases. Oral cavity oxidative stress and inflammation, consequent cigarettes due to nicotine and acrolein, may be reduced in the presence of green tea polyphenols. In addition, green tea polyphenols can close down halitosis through modification of odorant sulfur components. Usually, green tea defends healthy cells from malignant transformation and locally has the ability to induce apoptosis in oral cancer cells. In unison, there is an increasing implication in the health benefits of green tea in the field of oral health. This review will cover recent findings on the therapeutic properties and anticancer health benefits of green tea.
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Affiliation(s)
- Kavita Singhal
- Department of Oral Pathology, Career Dental College, Lucknow, Uttar Pradesh, India
| | - Neerja Raj
- Department of Prosthodontics, Career Dental College, Lucknow, Uttar Pradesh, India
| | - Khushboo Gupta
- Department of Oral Pathology, Faculty of Dentistry, AIMST University, Bedong 08100, Malaysia
| | - Saurabh Singh
- Department of Oral Surgery, Faculty of Dentistry, AIMST University, Bedong 08100, Malaysia
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Liu J, Liu S, Zhou H, Hanson T, Yang L, Chen Z, Zhou M. Association of green tea consumption with mortality from all-cause, cardiovascular disease and cancer in a Chinese cohort of 165,000 adult men. Eur J Epidemiol 2016; 31:853-65. [PMID: 27372743 DOI: 10.1007/s10654-016-0173-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 06/07/2016] [Indexed: 01/13/2023]
Abstract
Tea is the most ancient and popular beverage in the world, and its beneficial health effects has attracted tremendous attention worldwide. However, the prospective evidence relating green tea consumption to total and cause-specific mortality is still limited and inconclusive. We recruited 164,681 male participants free of pre-existing disease during 1990-1991, with green tea consumption and other covariates assessed by the standardized questionnaire and mortality follow up continued until 2006 (mean 11 years; total person-years: 1,961,791). Cox regression analyses were used to quantify the associations of green tea consumption with all-cause (n = 32,700), CVD (n = 11,839) and cancer (n = 7002) mortality, adjusting simultaneously for potential confounders. At baseline, 18 % reported regular consumption of green tea. Compared with non-green tea drinkers, regular drinkers had significantly lower all-cause mortality, with adjusted hazard ratios (HRs) being 0.94 (95 % CI 0.89, 0.99) for ≤5 g/day, 0.95 (0.91, 0.99) for 5-10 g/day and 0.89 (0.85, 0.93) for >10 g/day. For CVD mortality, the corresponding HRs were 0.93 (0.85, 1.01) 0.91 (0.85, 0.98) and 0.86 (0.79, 0.93), respectively, while for cancer they were 0.86 (0.78, 0.98), 0.92 (0.83, 1.00) and 0.79 (0.71, 0.88), respectively. The patterns of these associations varied by smoking, alcohol drinking and locality. This large prospective study shows that regular green tea consumption is associated with significantly reduced risk of death from all-cause, CVD and cancer among Chinese adults.
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Affiliation(s)
- Junxiu Liu
- Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA
| | - Shiwei Liu
- National Center for Chronic and Non-communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Richard Doll Building, Old Road Campus, Oxford, OX3-7LF, UK
| | - Haiming Zhou
- Division of Statistics, Northern Illinois University, Dekalb, IL, USA
| | - Timothy Hanson
- Department of Statistics, University of South Carolina, Columbia, SC, USA
| | - Ling Yang
- Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Richard Doll Building, Old Road Campus, Oxford, OX3-7LF, UK
| | - Zhengming Chen
- Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Richard Doll Building, Old Road Campus, Oxford, OX3-7LF, UK
| | - Maigeng Zhou
- National Center for Chronic and Non-communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
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Fuchs D, Nyakayiru J, Draijer R, Mulder TPJ, Hopman MTE, Eijsvogels TMH, Thijssen DH. Impact of flavonoid-rich black tea and beetroot juice on postprandial peripheral vascular resistance and glucose homeostasis in obese, insulin-resistant men: a randomized controlled trial. Nutr Metab (Lond) 2016; 13:34. [PMID: 27182277 PMCID: PMC4866334 DOI: 10.1186/s12986-016-0094-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 05/02/2016] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Insulin-stimulated muscle blood flow facilitates plasma glucose disposal after a meal, a mechanism that is impaired in obese, insulin-resistant volunteers. Nitrate- or flavonoid-rich products, through their proposed effects on nitric oxide, may improve postprandial blood flow and, subsequently, glucose disposal. To investigate whether a single dose of nitrate-rich beetroot juice or flavonoid-rich black tea lowers postprandial muscle vascular resistance in obese volunteers and alters postprandial glucose or insulin concentrations. METHOD In a randomised, controlled, cross-over study, 16 obese, insulin-resistant males consumed 75 g glucose, which was combined with 100 ml black tea, beetroot juice or control (water). Peripheral vascular resistance (VR), calculated as mean arterial pressure divided by blood flow, was assessed in the arm and leg conduit arteries, resistance arteries and muscle microcirculation across 3 h (every 30-min) after the oral glucose load. RESULTS During control, we found no postprandial response in VR in conduit, resistance and microvessels (all P > 0.05). Black tea decreased VR compared to control in conduit, resistance and microvessels (all P < 0.05). Beetroot juice decreased postprandial VR in resistance vessels, but not in conduit artery and microvessels. Although postprandial glucose response was similar after all interventions, postprandial insulin response was attenuated by ~29 % after tea (P < 0.0005), but not beetroot juice. CONCLUSIONS A single dose of black tea decreased peripheral VR across upper and lower limbs after a glucose load which was accompanied by a lower insulin response. Future studies in insulin-resistant subjects are warranted to confirm the observed effects and to explore whether long-term regular tea consumption affects glucose homeostasis. TRIAL REGISTRATION The study was registered at clinicaltrials.gov on 30(th) November 2012 (NCT01746329).
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Affiliation(s)
- Dagmar Fuchs
- />Unilever Research and Development, Vlaardingen, Olivier van Noortlaan 120, PO Box 114, 3130 AC Vlaardingen, The Netherlands
| | - Jean Nyakayiru
- />Research Institute for Health Sciences, Department of Physiology, Radboud University Medical Center, Geert Grooteplein-West 32, 6525 GA Nijmegen, The Netherlands
| | - Richard Draijer
- />Unilever Research and Development, Vlaardingen, Olivier van Noortlaan 120, PO Box 114, 3130 AC Vlaardingen, The Netherlands
| | - Theo P. J. Mulder
- />Unilever Research and Development, Vlaardingen, Olivier van Noortlaan 120, PO Box 114, 3130 AC Vlaardingen, The Netherlands
| | - Maria T. E. Hopman
- />Research Institute for Health Sciences, Department of Physiology, Radboud University Medical Center, Geert Grooteplein-West 32, 6525 GA Nijmegen, The Netherlands
| | - Thijs M. H. Eijsvogels
- />Research Institute for Health Sciences, Department of Physiology, Radboud University Medical Center, Geert Grooteplein-West 32, 6525 GA Nijmegen, The Netherlands
| | - Dick H. Thijssen
- />Research Institute for Health Sciences, Department of Physiology, Radboud University Medical Center, Geert Grooteplein-West 32, 6525 GA Nijmegen, The Netherlands
- />Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Byrom Street, L3 3AF Liverpool, UK
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Lee E, Lee BJ, Ha J, Shin HJ, Chung JO. Efficacy of fermented green tea on peripheral skin temperature: a randomized and placebo-controlled clinical study. J Cosmet Dermatol 2015; 15:226-30. [DOI: 10.1111/jocd.12205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/22/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Eunyoung Lee
- Skin Research Institute; IEC Korea; Suwon-si Korea
| | - Bum-jin Lee
- Food Research Institute; Amorepacific R&D Center; Yongin-si Korea
| | - Jaehyoun Ha
- Skin Research Institute; IEC Korea; Suwon-si Korea
| | - Hyun-jung Shin
- Food Research Institute; Amorepacific R&D Center; Yongin-si Korea
| | - Jin-oh Chung
- Food Research Institute; Amorepacific R&D Center; Yongin-si Korea
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Stull AJ, Cash KC, Champagne CM, Gupta AK, Boston R, Beyl RA, Johnson WD, Cefalu WT. Blueberries improve endothelial function, but not blood pressure, in adults with metabolic syndrome: a randomized, double-blind, placebo-controlled clinical trial. Nutrients 2015; 7:4107-23. [PMID: 26024297 PMCID: PMC4488775 DOI: 10.3390/nu7064107] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Revised: 05/08/2015] [Accepted: 05/18/2015] [Indexed: 12/12/2022] Open
Abstract
Blueberry consumption has been shown to have various health benefits in humans. However, little is known about the effect of blueberry consumption on blood pressure, endothelial function and insulin sensitivity in humans. The present study investigated the role of blueberry consumption on modifying blood pressure in subjects with metabolic syndrome. In addition, endothelial function and insulin sensitivity (secondary measurements) were also assessed. A double-blind and placebo-controlled study was conducted in 44 adults (blueberry, n = 23; and placebo, n = 21). They were randomized to receive a blueberry or placebo smoothie twice daily for six weeks. Twenty-four-hour ambulatory blood pressure, endothelial function and insulin sensitivity were assessed pre- and post-intervention. The blood pressure and insulin sensitivity did not differ between the blueberry and placebo groups. However, the mean change in resting endothelial function, expressed as reactive hyperemia index (RHI), was improved significantly more in the group consuming the blueberries versus the placebo group (p = 0.024). Even after adjusting for confounding factors, i.e., the percent body fat and gender, the blueberry group still had a greater improvement in endothelial function when compared to their counterpart (RHI; 0.32 ± 0.13 versus −0.33 ± 0.14; p = 0.0023). In conclusion, daily dietary consumption of blueberries did not improve blood pressure, but improved (i.e., increased) endothelial function over six weeks in subjects with metabolic syndrome.
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Affiliation(s)
- April J Stull
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA.
- Center for the Study of Botanicals and Metabolic Syndrome, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA.
| | - Katherine C Cash
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA.
| | - Catherine M Champagne
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA.
| | - Alok K Gupta
- Baton Rouge VA Outpatient Clinic, Southeast Louisiana Veterans Health Care System, 7968 Essen Park Avenue, Baton Rouge, LA 70809, USA.
| | - Raymond Boston
- Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19348, USA.
| | - Robbie A Beyl
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA.
| | - William D Johnson
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA.
- Center for the Study of Botanicals and Metabolic Syndrome, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA.
| | - William T Cefalu
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA.
- Center for the Study of Botanicals and Metabolic Syndrome, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA.
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Al-Awaida W, Akash M, Aburubaiha Z, Talib WH, Shehadeh H. Chinese green tea consumption reduces oxidative stress, inflammation and tissues damage in smoke exposed rats. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2014; 17:740-6. [PMID: 25729541 PMCID: PMC4340980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 07/01/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVES One cause of cigarette smoking is oxidative stress that may alter the cellular antioxidant defense system, induce apoptosis in lung tissue, inflammation and damage in liver, lung, and kidney. It has been shown that Chinese green tea (CGT) (Lung Chen Tea) has higher antioxidant property than black tea. In this paper, we will explore the preventive effect of CGT on cigarette smoke-induced oxidative damage, apoptosis and tissues inflammation in albino rat model. MATERIALS AND METHODS Albino rats were randomly divided into four groups, i.e. sham air (SA), cigarette smoke (CS), CGT 2% plus SA or plus CS. The exposure to smoking was carried out as a single daily dose (1 cigarette/rat) for a period of 90 days using an electronically controlled smoking machine. Sham control albino rats were exposed to air instead of cigarette smoke. Tissues were collected 24 hr after last CS exposure for histology and all enzyme assays. Apoptosis was evidenced by the fragmentation of DNA using TUNEL assay. RESULTS Long-term administration of cigarette smoke altered the cellular antioxidant defense system, induced apoptosis in lung tissue, inflammation and damage in liver, lung, and kidney. All these pathophysiological and biochemical events were significantly improved when the cigarette smoke-exposed albino rats were given CGT infusion as a drink instead of water. CONCLUSION Exposure of albino rat model to cigarette smoke caused oxidative stress, altered the cellular antioxidant defense system, induced apoptosis in lung tissue, inflammation and tissues damage, which could be prevented by supplementation of CGT.
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Affiliation(s)
- Wajdy Al-Awaida
- Department of Biology and Biotechnology, American University of Madaba, Madaba, Jordan
| | - Muhanad Akash
- Department of Biology and Biotechnology, American University of Madaba, Madaba, Jordan
- On Sabbatical leave from Faculty of Agriculture, The University of Jordan, Amman, Jordan
| | - Zaid Aburubaiha
- Department of Biology and Biotechnology, American University of Madaba, Madaba, Jordan
| | - Wamidh H. Talib
- Department of Clinical Pharmacy and Therapeutics, Applied Science University, Amman Jordan
| | - Hayel Shehadeh
- Department of Physics and Applied Sciences, American University of Madaba, Madaba, Jordan
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Abstract
The endothelium, a highly active structure, regulates vascular homeostasis through the release of numerous vasoactive factors that control vascular tone and vascular smooth cell proliferation. A larger number of medicinal plants and their isolated chemical constituents have been shown to beneficially affect the endothelium. For example, flavonoids in black tea, green tea, and concord grape cause a vasodilation possibly through their antioxidant properties. Allicin, a by-product of the enzyme alliinase, has been proposed to be the main active metabolite and responsible for most of the biological activities of garlic, including a dose-dependent dilation on the isolated coronaries. Thymoquinone, the principal phytochemical compound found in the volatile oil of the black seed, and the hawthorn extract have also been shown to improve aging-related impairment of endothelium-dependent relaxations in animal models. In this review, the effect of some of the natural products, including Camellia sinensis (black tea and green tea), Vitis labrusca (concord grape), Allium sativum (garlic), and Nigella sativa (black seed) and Crataegus ssp (hawthorn extract), is explored. The molecular mechanisms behind these potential therapeutic effects are also discussed.
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Munir KM, Chandrasekaran S, Gao F, Quon MJ. Mechanisms for food polyphenols to ameliorate insulin resistance and endothelial dysfunction: therapeutic implications for diabetes and its cardiovascular complications. Am J Physiol Endocrinol Metab 2013; 305:E679-86. [PMID: 23900418 PMCID: PMC4073986 DOI: 10.1152/ajpendo.00377.2013] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The rising epidemic of diabetes is a pressing issue in clinical medicine worldwide from both healthcare and economic perspectives. This is fueled by overwhelming increases in the incidence and prevalence of obesity. Obesity and diabetes are characterized by both insulin resistance and endothelial dysfunction that lead to substantial increases in cardiovascular morbidity and mortality. Reciprocal relationships between insulin resistance and endothelial dysfunction tightly link metabolic diseases including obesity and diabetes with their cardiovascular complications. Therefore, therapeutic approaches that target either insulin resistance or endothelial dysfunction alone are likely to simultaneously improve both metabolic and cardiovascular pathophysiology and disease outcomes. Moreover, combination therapies with agents targeting distinct mechanisms are likely to have additive or synergistic benefits. Conventional therapies for diabetes and its cardiovascular complications that are both safe and effective are insufficient to meet rising demand. Large, robust, epidemiologic studies demonstrate beneficial metabolic and cardiovascular health effects for many functional foods containing various polyphenols. However, precise molecular mechanisms of action for food polyphenols are largely unknown. Moreover, translation of these insights into effective clinical therapies has not been fully realized. Nevertheless, some functional foods are likely sources for safe and effective therapies and preventative strategies for metabolic diseases and their cardiovascular complications. In this review, we emphasize recent progress in elucidating molecular, cellular, and physiological actions of polyphenols from green tea (EGCG), cocoa (ECG), and citrus fruits (hesperedin) that are related to improving metabolic and cardiovascular pathophysiology. We also discuss a rigorous comprehensive approach to studying functional foods that is essential for developing novel, effective, and safe medications derived from functional foods that will complement existing conventional drugs.
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Affiliation(s)
- Kashif M Munir
- Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, Maryland; and
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19
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Bhardwaj P, Khanna D. Green tea catechins: defensive role in cardiovascular disorders. Chin J Nat Med 2013; 11:345-53. [DOI: 10.1016/s1875-5364(13)60051-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Indexed: 10/26/2022]
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20
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Hartley L, Flowers N, Holmes J, Clarke A, Stranges S, Hooper L, Rees K. Green and black tea for the primary prevention of cardiovascular disease. Cochrane Database Syst Rev 2013; 2013:CD009934. [PMID: 23780706 PMCID: PMC7433290 DOI: 10.1002/14651858.cd009934.pub2] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND There is increasing evidence that both green and black tea are beneficial for cardiovascular disease (CVD) prevention. OBJECTIVES To determine the effects of green and black tea on the primary prevention of CVD. SEARCH METHODS We searched the following databases on 12 October 2012 without language restrictions: CENTRAL in The Cochrane Library, MEDLINE (OVID), EMBASE (OVID) and Web of Science (Thomson Reuters). We also searched trial registers, screened reference lists and contacted authors for additional information where necessary. SELECTION CRITERIA Randomised controlled trials (RCTs) lasting at least three months involving healthy adults or those at high risk of CVD. Trials investigated the intake of green tea, black tea or tea extracts. The comparison group was no intervention, placebo or minimal intervention. The outcomes of interest were CVD clinical events and major CVD risk factors. Any trials involving multifactorial lifestyle interventions or focusing on weight loss were excluded to avoid confounding. DATA COLLECTION AND ANALYSIS Two review authors independently selected trials for inclusion, abstracted data and assessed the risk of bias. Trials of green tea were analysed separately from trials of black tea. MAIN RESULTS We identified 11 RCTs with a total of 821 participants, two trials awaiting classification and one ongoing trial. Seven trials examined a green tea intervention and four examined a black tea intervention. Dosage and form of both green and black tea differed between trials. The ongoing trial is examining the effects of green tea powder capsules.No studies reported cardiovascular events.Black tea was found to produce statistically significant reductions in low-density lipoprotein (LDL) cholesterol (mean difference (MD) -0.43 mmol/L, 95% confidence interval (CI) -0.56 to -0.31) and blood pressure (systolic blood pressure (SBP): MD -1.85 mmHg, 95% CI -3.21 to -0.48. Diastolic blood pressure (DBP): MD -1.27 mmHg, 95% CI -3.06 to 0.53) over six months, stable to sensitivity analysis, but only a small number of trials contributed to each analysis and studies were at risk of bias.Green tea was also found to produce statistically significant reductions in total cholesterol (MD -0.62 mmol/L, 95% CI -0.77 to -0.46), LDL cholesterol (MD -0.64 mmol/L, 95% CI -0.77 to -0.52) and blood pressure (SBP: MD -3.18 mmHg, 95% CI -5.25 to -1.11; DBP: MD -3.42, 95% CI -4.54 to -2.30), but only a small number of studies contributed to each analysis, and results were not stable to sensitivity analysis. When both tea types were analysed together they showed favourable effects on LDL cholesterol (MD -0.48 mmol/L, 95% CI -0.61 to -0.35) and blood pressure (SBP: MD -2.25 mmHg, 95% CI -3.39 to -1.11; DBP: MD -2.81 mmHg, 95% CI -3.77 to -1.86). Adverse events were measured in five trials and included a diagnosis of prostate cancer, hospitalisation for influenza, appendicitis and retinal detachment but these are unlikely to be directly attributable to the intervention. AUTHORS' CONCLUSIONS There are very few long-term studies to date examining green or black tea for the primary prevention of CVD. The limited evidence suggests that tea has favourable effects on CVD risk factors, but due to the small number of trials contributing to each analysis the results should be treated with some caution and further high quality trials with longer-term follow-up are needed to confirm this.
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Affiliation(s)
- Louise Hartley
- Warwick Medical School, University of WarwickDivision of Health SciencesCoventryWarwickshireUKCV4 7AL
| | - Nadine Flowers
- Warwick Medical School, University of WarwickDivision of Health SciencesCoventryWarwickshireUKCV4 7AL
| | | | - Aileen Clarke
- Warwick Medical School, University of WarwickDivision of Health SciencesCoventryWarwickshireUKCV4 7AL
| | - Saverio Stranges
- Warwick Medical School, University of WarwickDivision of Health SciencesCoventryWarwickshireUKCV4 7AL
| | - Lee Hooper
- University of East AngliaNorwich Medical SchoolNorwich Research ParkNorwichUKNR4 7TJ
| | - Karen Rees
- Warwick Medical School, University of WarwickDivision of Health SciencesCoventryWarwickshireUKCV4 7AL
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Abstract
Research into the cognitive and mood effects of caffeine in human subjects has highlighted some fairly robust and well-accepted effects. However, the majority of these studies have focused on caffeine in isolation; whilst caffeine is normally consumed in the form of plant-derived products and extracts that invariably contain other potentially bioactive phytochemicals. The aim of the present review is to consider the possible mechanisms of action of co-occurring phytochemicals, and any epidemiological evidence suggesting that they contribute to potential health benefits ascribed to caffeine. Intervention studies to date that have been conducted to explore the effects on brain function of the non-caffeine components in caffeine-bearing plants (coffee, tea, cocoa, guaraná), either alone or in combination with caffeine, will also be summarised. Research is beginning to accumulate showing independent effects for several of the phytochemicals that co-occur with caffeine, and/or a modulation of the effects of caffeine when it is co-consumed with these naturally concomitant phytochemicals. The present review highlights that more research aimed at understanding the effects of these compounds is needed and, more importantly, the synergistic relationship that they may have with caffeine.
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Miller RJ, Jackson KG, Dadd T, Mayes AE, Brown AL, Lovegrove JA, Minihane AM. The impact of the catechol-O-methyltransferase genotype on vascular function and blood pressure after acute green tea ingestion. Mol Nutr Food Res 2012; 56:966-75. [PMID: 22707271 DOI: 10.1002/mnfr.201100726] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
SCOPE Evidence for the benefits of green tea catechins on vascular function is inconsistent, with genotype potentially contributing to the heterogeneity in response. Here, the impact of the catechol-O-methyltransferase (COMT) genotype on vascular function and blood pressure (BP) after green tea extract ingestion are reported. METHODS AND RESULTS Fifty subjects (n = 25 of the proposed low-activity [AA] and of the high-activity [GG] COMT rs4680 genotype), completed a randomized, double-blind, crossover study. Peripheral arterial tonometry, digital volume pulse (DVP), and BP were assessed at baseline and 90 min after 1.06 g of green tea extract or placebo. A 5.5 h and subsequent 18.5 h urine collection was performed to assess green tea catechin excretion. A genotype × treatment interaction was observed for DVP reflection index (p = 0.014), with green tea extract in the AA COMT group attenuating the increase observed with placebo. A tendency for a greater increase in diastolic BP was evident at 90 min after the green tea extract compared to placebo (p = 0.07). A genotypic effect was observed for urinary methylated epigallocatechin during the first 5.5 h, with the GG COMT group demonstrating a greater concentration (p = 0.049). CONCLUSION Differences in small vessel tone according to COMT genotype were evident after acute green tea extract.
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Affiliation(s)
- Rosalind J Miller
- Department of Food and Nutritional Sciences, University of Reading, Reading, UK
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Dell’agli M, Di Lorenzo C, Badea M, Sangiovanni E, Dima L, Bosisio E, Restani P. Plant Food Supplements with Anti-Inflammatory Properties: A Systematic Review (I). Crit Rev Food Sci Nutr 2012; 53:403-13. [DOI: 10.1080/10408398.2012.682123] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Mario Dell’agli
- a Department of Pharmacological and Biomolecular Sciences , Università degli Studi di Milano , Via Balzaretti 9, 20133 , Milano , Italy
| | - Chiara Di Lorenzo
- a Department of Pharmacological and Biomolecular Sciences , Università degli Studi di Milano , Via Balzaretti 9, 20133 , Milano , Italy
| | - Mihaela Badea
- b Faculty of Medicine , Transilvania University of Brasov, Str. Nicolae Balcescu 56 , Brasov , Romania
| | - Enrico Sangiovanni
- a Department of Pharmacological and Biomolecular Sciences , Università degli Studi di Milano , Via Balzaretti 9, 20133 , Milano , Italy
| | - Lorena Dima
- b Faculty of Medicine , Transilvania University of Brasov, Str. Nicolae Balcescu 56 , Brasov , Romania
| | - Enrica Bosisio
- a Department of Pharmacological and Biomolecular Sciences , Università degli Studi di Milano , Via Balzaretti 9, 20133 , Milano , Italy
| | - Patrizia Restani
- a Department of Pharmacological and Biomolecular Sciences , Università degli Studi di Milano , Via Balzaretti 9, 20133 , Milano , Italy
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Wightman EL, Haskell CF, Forster JS, Veasey RC, Kennedy DO. Epigallocatechin gallate, cerebral blood flow parameters, cognitive performance and mood in healthy humans: a double-blind, placebo-controlled, crossover investigation. Hum Psychopharmacol 2012; 27:177-86. [PMID: 22389082 DOI: 10.1002/hup.1263] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE The aim of the study was to assess the effects of oral ingestion of the 'green tea' polyphenol epigallocatechin gallate (EGCG) on cognitive performance, mood and localised cerebral blood flow (CBF) parameters in healthy human adults. METHOD In this double-blind, placebo-controlled, crossover study, 27 healthy adults received placebo and two doses (135 and 270 mg) of EGCG in counterbalanced order on separate days. Following a 45-min resting absorption period, participants performed a selection of computerised cognitive tasks that activate the frontal cortex for a further 42 min. CBF and haemodynamics, as indexed by concentration changes in oxygenated and deoxygenated haemoglobin, were assessed in the frontal cortex throughout the post-treatment period using Near-infrared spectroscopy (NIRS). RESULTS During the post-dose task performance period, the administration of 135 mg EGCG resulted in reduced CBF in the frontal cortex, as indexed by significantly lower concentrations of both oxygenated and total haemoglobin, in comparison with placebo. Heart rate was significantly reduced from pre dose to post dose across all treatments. No significant differences were observed for the level of deoxygenated haemoglobin or on any of the cognitive performance/mood measures. CONCLUSIONS These results demonstrate that a single dose of orally administered EGCG can modulate CBF parameters in healthy humans but that this is not associated with changes in cognitive performance or mood.
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Affiliation(s)
- Emma L Wightman
- Brain, Performance and Nutrition Research Centre, Northumbria University, Newcastle upon Tyne, United Kingdom
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Health effects of green tea catechins in overweight and obese men: a randomised controlled cross-over trial. Br J Nutr 2011; 106:1880-9. [PMID: 21736785 DOI: 10.1017/s0007114511002376] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Regular consumption of green tea may be cardioprotective. In the present study we investigated the health effects of dietary supplementation with green tea catechins and the potential modifying effect of the catechol-O-methyltransferase (COMT) Val/Met genotype. Subjects (sedentary males, aged 40-69 years, with BMI ≥ 28 and ≤ 38 kg/m(2)) were randomly assigned to consume decaffeinated green tea extract (DGT; 530 mg containing about 400 mg total catechins/capsule, twice daily) and placebo in a complete cross-over design. Ambulatory blood pressure and biomarkers of metabolic function (cholesterol, TAG, glucose and insulin) were measured at weeks 0 and 6. Although a marked increase in the concentration of plasma epigallocatechin gallate (EGCG), urinary epigallocatechin (EGC) and urinary 4'-O-methyl EGC was found after DGT treatment, no effect on blood pressure or biomarkers of metabolic function was observed. However, a period × treatment interaction (P < 0·05) was detected for body-weight change. Despite a similar increase in estimated energy intake during intervention period 1, body weight decreased by 0·64 (sd 2·2) kg and increased by 0·53 (sd 1·9) kg in the DGT and placebo groups, respectively (P = 0·025), suggesting a protective effect of green tea catechins on weight gain. Additionally, the COMT Val/Met genotype influenced urinary accumulation of EGC and 4'-O-methyl EGC (P < 0·01). Mean concentrations were lower in individuals homozygous for the high-activity G-allele, possibly reflecting increased metabolic flux and a more rapid conversion to downstream metabolic species, compared with individuals carrying at least one copy of the low-activity A-allele. Additional studies are needed to confirm these findings and further explore the modifying effect of genotype.
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Gokulakrisnan A, Jayachandran Dare B, Thirunavukkarasu C. Attenuation of the cardiac inflammatory changes and lipid anomalies by (−)-epigallocatechin-gallate in cigarette smoke-exposed rats. Mol Cell Biochem 2011; 354:1-10. [DOI: 10.1007/s11010-011-0785-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Accepted: 03/07/2011] [Indexed: 10/18/2022]
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Scientific Opinion on the substantiation of health claims related to Camellia sinensis (L.) Kuntze (tea), including catechins in green tea, and improvement of endothelium-dependent vasodilation (ID 1106, 1310), maintenance of normal blood pressure (ID 131. EFSA J 2011. [DOI: 10.2903/j.efsa.2011.2055] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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The impact of the catechol-O-methyltransferase genotype on the acute responsiveness of vascular reactivity to a green tea extract. Br J Nutr 2010; 105:1138-44. [PMID: 21144097 DOI: 10.1017/s0007114510004836] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The beneficial effects of green tea catechins, such as the proposed improvement in endothelial function, may be influenced by phase II metabolism during and after absorption. The methylation enzyme, catechol-O-methyltransferase (COMT), has a missense mutation rs4680 (G to A), proposed to result in a 40 % reduction in enzyme activity. In the present pilot study, twenty subjects (ten of each homozygous COMT genotype) were recruited. Green tea extract capsules (836 mg green tea catechins) were given in a fasted state, and a high-carbohydrate breakfast was given after 60 min. Blood samples and vascular function measurements were taken at regular intervals. The change in digital volume pulse stiffness index (SI) from baseline was shown to be different between genotype groups at 120 and 240 min, with a lower SI in the GG individuals (P ≤ 0·044). The change in blood pressure from baseline also differed between genotype groups, with a greater increase in systolic (P = 0·023) and diastolic (P = 0·034) blood pressure at 120 min in the GG group. The GG [corrected] group was shown to have a greater increase in insulin concentrations at 120 min (P = 0·019) and 180 min (P = 0·008) compared with baseline, despite similar glucose profiles. No genotypic differences were found in vascular reactivity measured using laser Doppler iontophoresis, total nitrite, lipids, plasma total antioxidant capacity or inflammatory markers after ingestion of the green tea extract. In conclusion, SI and insulin response to the glucose load differed between the COMT genotype groups, and this may be suggestive of a green tea extract and genotype interaction.
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Gokulakrisnan A, Vinayagam MM, Rahman LAA, Thirunavukkarasu C. WITHDRAWN: Attenuation of cardiac oxidative stress by (-)-epigallocatechin-gallate (EGCG) in CS exposed rats. Biomed Pharmacother 2010:S0753-3322(10)00183-6. [PMID: 21115319 DOI: 10.1016/j.biopha.2010.09.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Accepted: 09/30/2010] [Indexed: 01/08/2023] Open
Abstract
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Adikesavan Gokulakrisnan
- Department of Biochemistry, Periyar University, Salem 636016, Tamil Nadu, India; Department of Biochemistry, Islamiah College, Vaniyambadi, Tamil Nadu, India
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Goldberg RJ, Nakagawa T, Johnson RJ, Thurman JM. The role of endothelial cell injury in thrombotic microangiopathy. Am J Kidney Dis 2010; 56:1168-74. [PMID: 20843591 DOI: 10.1053/j.ajkd.2010.06.006] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Accepted: 06/07/2010] [Indexed: 01/01/2023]
Abstract
Thrombotic microangiopathy (TMA) refers to a clinical and pathologic syndrome in which endothelial injury results in the manifestations of thrombocytopenia, microangiopathic hemolytic anemia, and kidney injury. A host of causes may induce endothelial injury and TMA, including enteric bacterial toxins, deficiency or dysfunction of complement regulatory proteins, deficiency or inhibition of von Willebrand factor-cleaving proteases, and factors that inhibit endothelial cell proliferation and turnover. This has led specialists to concentrate on these specific inciting factors in terms of designing treatment and management. However, a key and less recognized factor is the underlying level of endothelial health. Many persons with hereditary causes may remain disease free for years or may never develop disease. Others with acute inciting events, such as Escherichia coli O157 enteritis, never manifest TMA. Experimental studies document the importance of specific factors, such as endothelial nitric oxide levels, in helping protect animals from TMA. This suggests that one might approach the management of TMA not simply with specific treatments aimed at the underlying hereditary cause or inciting event, but rather at general measures that may improve overall endothelial health. We propose studies to determine whether interventions that improve endothelial health, such as the administration of angiotensin-converting enzyme inhibitors, statins, vitamin C, allopurinol, or nitric oxide-producing drugs, may be able to prevent TMA, even in persons with underlying hereditary conditions that otherwise would predispose them to these diseases.
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Affiliation(s)
- Ryan J Goldberg
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, CO, USA.
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Hodgson JM, Croft KD. Tea flavonoids and cardiovascular health. Mol Aspects Med 2010; 31:495-502. [PMID: 20837049 DOI: 10.1016/j.mam.2010.09.004] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 09/02/2010] [Accepted: 09/02/2010] [Indexed: 12/21/2022]
Abstract
The two main types of tea are green and black. Both green and black teas are rich dietary sources of flavonoids. Available evidence suggests that regular tea consumption may reduce the risk of cardiovascular disease. The cardiovascular health benefits of drinking tea are thought to be largely due to flavonoids. Tea intake and intake of flavonoids found in tea have been associated with reduced risk of cardiovascular disease in cross-sectional and prospective population studies. Isolated flavonoids found in tea have also been consistently shown to inhibit the development of atherosclerosis in animal models. A number of possible pathways and mechanisms have been investigated. There is now consistent data indicating that tea and tea flavonoids can enhance nitric oxide status and improve endothelial function, which may be at least partly responsible for benefits on cardiovascular health. There is also evidence, although limited, to suggest benefits of green tea (flavonoids) on body weight and body fatness. Data supporting reduced oxidative damage, inflammation, platelet activation, blood pressure, and risk of type 2 diabetes with tea (flavonoids) remains inadequate to draw any conclusions.
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Affiliation(s)
- Jonathan M Hodgson
- School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia, Australia.
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Augustyniak A, Bartosz G, Čipak A, Duburs G, Horáková L, Łuczaj W, Majekova M, Odysseos AD, Rackova L, Skrzydlewska E, Stefek M, Štrosová M, Tirzitis G, Venskutonis PR, Viskupicova J, Vraka PS, Žarković N. Natural and synthetic antioxidants: An updated overview. Free Radic Res 2010; 44:1216-62. [DOI: 10.3109/10715762.2010.508495] [Citation(s) in RCA: 177] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Reis JP, Loria CM, Steffen LM, Zhou X, van Horn L, Siscovick DS, Jacobs DR, Carr JJ. Coffee, decaffeinated coffee, caffeine, and tea consumption in young adulthood and atherosclerosis later in life: the CARDIA study. Arterioscler Thromb Vasc Biol 2010; 30:2059-66. [PMID: 20616310 DOI: 10.1161/atvbaha.110.208280] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To determine the association of coffee, decaffeinated coffee, caffeine, and tea consumption in young adulthood with the presence and progression of coronary artery calcified (CAC) plaque and carotid intima-media thickness later in life. METHODS AND RESULTS The Coronary Artery Risk Development in Young Adults (CARDIA) Study is a cohort of 5115 white and black adults who were aged 18 to 30 years when they completed a baseline clinic examination from 1985 to 1986. Subsequent examinations were conducted 2, 5, 7, 10, 15, and 20 years later. After multivariable adjustment, no association was observed between average coffee, decaffeinated coffee, or caffeine consumption (years 0 and 7) and presence of CAC (score, >0 Agatston units at year 15 or 20), CAC progression (incident CAC at year 20 or increase in CAC score by ≥20 Agatston units), or high carotid intima-media thickness (>80th percentile, year 20). However, tea consumption displayed a nonsignificant trend for an inverse association with CAC (P=0.08 for trend) and an inverse association with CAC progression (P=0.04 for trend) but no association with high carotid intima-media thickness (P>0.20 for trend). Stratification of the coffee analyses by sex, race, or smoking yielded similar nonsignificant patterns. CONCLUSIONS We observed no substantial association between coffee or caffeine intake and coronary and carotid atherosclerosis. However, our results suggested an inverse association between tea and CAC but not carotid atherosclerosis.
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Affiliation(s)
- Jared P Reis
- Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, Bethesda, Md 20892, USA.
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Zuchi C, Ambrosio G, Lüscher TF, Landmesser U. Nutraceuticals in Cardiovascular Prevention: Lessons from Studies on Endothelial Function. Cardiovasc Ther 2010; 28:187-201. [DOI: 10.1111/j.1755-5922.2010.00165.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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Scientific Opinion on the substantiation of health claims related to Camellia sinensis (L.) Kuntze (tea), including catechins in green tea and tannins in black tea, and protection of DNA, proteins and lipids from oxidative damage (ID 1103, 1276, 1311, 1708, 2664), reduction of acid production in dental plaque (ID 1105, 1111), maintenance of bone (ID 1109), decreasing potentially pathogenic intestinal microorganisms (ID 1116), maintenance of vision (ID 1280), maintenance of normal blood pressure (ID 1546) and maintenance of normal blood cholesterol concentrations (ID 1113, 1114) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA J 2010. [DOI: 10.2903/j.efsa.2010.1463] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Abstract
The health benefits of green tea (Camellia sinensis) catechins are becoming increasingly recognised. Amongst the proposed benefits are the maintenance of endothelial function and vascular homeostasis and an associated reduction in atherogenesis and CVD risk. The mounting evidence for the influential effect of green tea catechins on vascular function from epidemiological, human intervention and animal studies is subject to review together with exploration of the potential mechanistic pathways involved. Epigallocatechin-3-gallate, one of the most abundant and widely studied catechin found in green tea, will be prominent in the present review. Since there is a substantial inconsistency in the published data with regards to the impact of green tea catechins on vascular function, evaluation and interpretation of the inter- and intra-study variability is included. In conclusion, a positive effect of green tea catechins on vascular function is becoming apparent. Further studies in animal and cell models using physiological concentrations of catechins and their metabolites are warranted in order to gain some insight into the physiology and molecular basis of the observed beneficial effects.
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Oyama JI, Maeda T, Kouzuma K, Ochiai R, Tokimitsu I, Higuchi Y, Sugano M, Makino N. Green Tea Catechins Improve Human Forearm Endothelial Dysfunction and Have Antiatherosclerotic Effects in Smokers. Circ J 2010; 74:578-88. [DOI: 10.1253/circj.cj-09-0692] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jun-ichi Oyama
- Department of Cardiovascular, Respiratory and Geriatric Medicine, Kyushu University Hospital at Beppu and Medical Institute of Bioregulation, Kyushu University
| | - Toyoki Maeda
- Department of Cardiovascular, Respiratory and Geriatric Medicine, Kyushu University Hospital at Beppu and Medical Institute of Bioregulation, Kyushu University
| | | | | | | | - Yoshihiro Higuchi
- Department of Cardiovascular, Respiratory and Geriatric Medicine, Kyushu University Hospital at Beppu and Medical Institute of Bioregulation, Kyushu University
| | - Masahiro Sugano
- Department of Cardiovascular, Respiratory and Geriatric Medicine, Kyushu University Hospital at Beppu and Medical Institute of Bioregulation, Kyushu University
| | - Naoki Makino
- Department of Cardiovascular, Respiratory and Geriatric Medicine, Kyushu University Hospital at Beppu and Medical Institute of Bioregulation, Kyushu University
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Li Y, Ying C, Zuo X, Yi H, Yi W, Meng Y, Ikeda K, Ye X, Yamori Y, Sun X. Green tea polyphenols down-regulate caveolin-1 expression via ERK1/2 and p38MAPK in endothelial cells. J Nutr Biochem 2009; 20:1021-7. [DOI: 10.1016/j.jnutbio.2008.12.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2008] [Revised: 11/26/2008] [Accepted: 12/01/2008] [Indexed: 10/21/2022]
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Effects of co-administration of tea epigallocatechin-3-gallate (EGCG) and caffeine on absorption and metabolism of EGCG in humans. Biosci Biotechnol Biochem 2009; 73:2014-7. [PMID: 19734672 DOI: 10.1271/bbb.90195] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Based on the ratios of (-)-epigallocatechin-3-gallate (EGCG) and caffeine (CAF) levels found in commercial tea drinks, EGCG and CAF were co-administered to human volunteers at various EGCG/CAF ratios, and plasma EGCG was determined by high performance liquid chromatography with chemiluminescence detection. As for the results, in plasma taken after ingestion of a beverage containing 95 mg of EGCG alone, the area under the plasma EGCG concentration-time curve (AUC) was 857 ngxh/ml. A higher AUC (1,370 ngxh/ml) was observed when subjects ingested a beverage containing EGCG (95 mg) and a low amount of CAF (40 mg). In the case of ingestion of a beverage containing EGCG (95 mg) and a high amount of CAF (180 mg), the AUC tended to be somewhat higher (1,165 ngxh/ml), but not significantly so, compared with the beverage with EGCG alone. These findings (modulation of plasma EGCG level by CAF) provide ideas for modulating the bioavailability of tea catechins, which can be applied to tea-related drinks and foods.
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Schmitt CA, Dirsch VM. Modulation of endothelial nitric oxide by plant-derived products. Nitric Oxide 2009; 21:77-91. [DOI: 10.1016/j.niox.2009.05.006] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 04/28/2009] [Accepted: 05/26/2009] [Indexed: 12/31/2022]
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Abstract
OBJECTIVES Flavonoids may protect against cardiovascular disease. Tea is a major source of dietary flavonoids. Studies indicate black tea improves endothelial function but data on arterial haemodynamics, blood pressure (BP) and insulin resistance are equivocal. Inconsistency may be due to flaws in study design or flavonoid doses tested. Further, no study has evaluated the dose-response curve. Our study aimed to test the effects of various doses of black tea on vascular function, BP and insulin resistance. METHODS According to a randomized, double-blind, controlled, cross-over design, 19 healthy men were assigned to receive either five treatments with a twice daily intake of black tea (0, 100, 200, 400 and 800 mg tea flavonoids/day) in five periods lasting 1 week each. RESULTS Black tea dose dependently increased flow-mediated dilation (FMD) from 7.8% (control) to 9.0, 9.1, 9.6 and 10.3% after the different flavonoid doses, respectively (P = 0.0001). Already 100 mg/day (less than 1 cup of tea) increased FMD compared with control (P = 0.0113). FMD improvement after 800 mg/day was significant compared with control (P < 0.0001) but also to 100 mg/day (P = 0.0121) and 200 mg/day (P = 0.0275). Black tea intake decreased office systolic (-2.6 mmHg, P = 0.0007) and diastolic (-2.2 mmHg, P = 0.006) BP as well as stiffness index (P = 0.0159) without changes in other parameters studied. CONCLUSION Our study is the first showing black tea ingestion dose dependently improved FMD and decreased peripheral arterial stiffness in healthy volunteers. Our data suggest that worldwide all tea drinkers could benefit from protective cardiovascular effects exerted by tea.
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Clement Y. Can green tea do that? A literature review of the clinical evidence. Prev Med 2009; 49:83-7. [PMID: 19465043 DOI: 10.1016/j.ypmed.2009.05.005] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2009] [Revised: 05/01/2009] [Accepted: 05/16/2009] [Indexed: 01/15/2023]
Abstract
OBJECTIVE Habitual green tea consumption has long been associated with health benefits including chemoprevention and cardiovascular protection. This non-systematic literature review presents the clinical evidence to date. METHOD A literature review of peer-reviewed articles on observational and interventional studies was conducted to include green tea, its extract or its purified polyphenol (-)-epigallocatechin-3-gallate (EGCG). Electronic databases searched included PubMed (1966-2009) and the Cochrane Library (Issue 4, 2008). RESULTS Observational studies are inconclusive on the benefits of habitual consumption of green tea in the prevention of most cancers. However, there are trends towards prevention in breast and prostate cancers. Interventional studies have demonstrated reduction in relapses following surgical resection in colorectal adenomas and increased survival rates in epithelial ovarian cancer. Observational studies indicate that green tea may provide protection against hypertension and reduce the risk for stroke, and interventional studies are providing biochemical and physiological evidence. CONCLUSION Although the overall clinical evidence is inconclusive, habitual green tea consumption may be providing some level of chemoprevention in prostate and breast cancer. Green tea may also attenuate the risk factors association with the development of atherosclerosis thus reducing the incidence of cardiovascular events and stoke.
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Affiliation(s)
- Yuri Clement
- Pharmacology Unit, Faculty of Medical Sciences, The University of the West Indies, St. Augustine, Trinidad and Tobago.
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Chan KH, Ho SP, Yeung SC, So WHL, Cho CH, Koo MWL, Lam WK, Ip MSM, Man RYK, Mak JCW. Chinese green tea ameliorates lung injury in cigarette smoke-exposed rats. Respir Med 2009; 103:1746-54. [PMID: 19487113 DOI: 10.1016/j.rmed.2009.04.027] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2008] [Revised: 04/17/2009] [Accepted: 04/28/2009] [Indexed: 11/25/2022]
Abstract
BACKGROUND Epigallocatechin-3-gallate (EGCG), which has been shown to have potent antioxidant effect, comprises 80% of catechins in Chinese green tea. This study was to investigate whether cigarette smoke (CS) exposure would induce lung morphological changes and oxidative stress in the CS-exposed rat model, and whether Chinese green tea (Lung Chen tea with EGCG as its main active ingredient) consumption would alter oxidative stress in sera and lung leading to protection of CS-induced lung damage. METHODS Sprague-Dawley rats were randomly divided into four groups, i.e. sham air (SA), 4% CS, 2% Lung Chen tea plus SA or 4% CS. Exposure to SA or 4% CS was performed for 1h/day for 56 days in ventilated smoking chambers. Sera and lung tissues were collected 24h after last CS exposure for histology and all biochemical assays. RESULTS Airspace enlargement and goblet cell hyperplasia were observed after 56-day CS exposure alone, which were abolished in the presence of green tea consumption. Serum 8-isoprostane level was significantly elevated (p<0.01) as well as lung superoxide dismutase (SOD) and catalase activities in CS-exposed rats compared to SA-exposed rats (p<0.05), which returned to the levels of SA-exposed rats after Chinese green tea consumption. CONCLUSION These results indicate that increased levels of systemic oxidative stress after CS exposure play an important role in the induction of lung damage. Chinese green tea may have the ability to suppress CS-induced oxidative stress that leads to protection of lung injury.
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Affiliation(s)
- Ka H Chan
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
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Affiliation(s)
- Roberto Corti
- From the Cardiovascular Center, Cardiology University Hospital, Zurich, Switzerland (R.C., A.J.F., T.F.L.), and Department of Medicine and Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Mass (N.K.H.)
| | - Andreas J. Flammer
- From the Cardiovascular Center, Cardiology University Hospital, Zurich, Switzerland (R.C., A.J.F., T.F.L.), and Department of Medicine and Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Mass (N.K.H.)
| | - Norman K. Hollenberg
- From the Cardiovascular Center, Cardiology University Hospital, Zurich, Switzerland (R.C., A.J.F., T.F.L.), and Department of Medicine and Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Mass (N.K.H.)
| | - Thomas F. Lüscher
- From the Cardiovascular Center, Cardiology University Hospital, Zurich, Switzerland (R.C., A.J.F., T.F.L.), and Department of Medicine and Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Mass (N.K.H.)
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Frank J, George TW, Lodge JK, Rodriguez-Mateos AM, Spencer JPE, Minihane AM, Rimbach G. Daily consumption of an aqueous green tea extract supplement does not impair liver function or alter cardiovascular disease risk biomarkers in healthy men. J Nutr 2009; 139:58-62. [PMID: 19056646 DOI: 10.3945/jn.108.096412] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Regular consumption of green tea polyphenols (GTP) is thought to reduce the risk of cardiovascular disease (CVD) but has also been associated with liver toxicity. The present trial aimed to assess the safety and potential CVD health beneficial effects of daily GTP consumption. We conducted a placebo-controlled parallel study to evaluate the chronic effects of GTP on liver function and CVD risk biomarkers in healthy men. Volunteers (treatment: n = 17, BMI 26.7 +/- 3.3 kg/m(2), age 41 +/- 9 y; placebo, n = 16, BMI 25.4 +/- 3.3 kg/m(2), age 40 +/- 10 y) consumed for 3 wk 6 capsules per day (2 before each principal meal) containing green tea extracts (equivalent to 714 mg/d GTP) or placebo. At the beginning and end of the intervention period, we collected blood samples from fasting subjects and measured vascular tone using Laser Doppler Iontophoresis. Biomarkers of liver function and CVD risk (including blood pressure, plasma lipids, and asymmetric dimethylarginine) were unaffected by GTP consumption. After treatment, the ratio of total:HDL cholesterol was significantly reduced in participants taking GTP capsules compared with baseline. Endothelial-dependent and -independent vascular reactivity did not significantly differ between treatments. In conclusion, the present data suggests that the daily consumption of high doses of GTP by healthy men for 3 wk is safe but without effects on CVD risk biomarkers other than the total:HDL cholesterol ratio.
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Affiliation(s)
- Jan Frank
- Institute of Human Nutrition and Food Science, Christian-Albrechts-University, 24118 Kiel, Germany.
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Thielecke F, Boschmann M. The potential role of green tea catechins in the prevention of the metabolic syndrome - a review. PHYTOCHEMISTRY 2009; 70:11-24. [PMID: 19147161 DOI: 10.1016/j.phytochem.2008.11.011] [Citation(s) in RCA: 231] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Revised: 11/20/2008] [Accepted: 11/20/2008] [Indexed: 05/17/2023]
Abstract
The metabolic syndrome (MetS) represents an emerging health burden for governments and health care providers. Particularly relevant for prevention and early management of MetS are lifestyle conditions including physical activity and the diet. It has been shown that green tea, when consumed on a daily basis, supports health. Many of the beneficial effects of green tea are related to its catechin, particularly (-)-epigallocatechin-3-gallate (EGCG), content. There is conclusive evidence from in vitro and animal studies which provide the concepts for underlying functional mechanisms of green tea catechins and their biological actions. An increasing number of human studies have explored the effects of green tea catechins on the major MetS conditions such as obesity, type-2 diabetes and cardiovascular risk factors. This article provides a comprehensive overview of the human studies addressing the potential benefits of green tea catechins on the MetS. The number of human studies in this field is still limited. However, the majority of human epidemiological and intervention studies demonstrate beneficial effects of green tea or green tea extracts, rich in EGCG on weight management, glucose control and cardiovascular risk factors. The optimal dose has not yet been established. The current body of evidence in humans warrants further attention. In particular, well-controlled long-term human studies would help to fully understand the protective effects of green tea catechins on parameters related to the MetS.
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Affiliation(s)
- Frank Thielecke
- DSM Nutritional Products Ltd., New Business Development, Human Nutrition and Health, P.O. Box 2676, Bldg. 241/965, 4002 Basel, CH, Switzerland.
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Jochmann N, Baumann G, Stangl V. Green tea and cardiovascular disease: from molecular targets towards human health. Curr Opin Clin Nutr Metab Care 2008; 11:758-65. [PMID: 18827581 DOI: 10.1097/mco.0b013e328314b68b] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PURPOSE OF REVIEW To summarize current knowledge of the protective effects of green tea and green tea constituents, particularly catechins, on the cardiovascular system. RECENT FINDINGS Consumption of green tea has been inversely associated with the development and progression of cardiovascular diseases and cardiovascular risk factors. Mechanisms that have been suggested as being involved in the antiatherosclerotic effects of green tea consumption primarily entail antioxidative, antiinflammatory, antiproliferative, and antithrombotic properties, as well as beneficial effects on endothelial function. Moreover, evidence exists for myocardial effects of tea constituents, including positive inotropic and antihypertrophic effects, and beneficial impact in myocardial ischaemia-reperfusion injury. SUMMARY Green tea represents a promising tool for the prevention of cardiovascular disorders.
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Affiliation(s)
- Nicoline Jochmann
- Medizinische Klinik mit Schwerpunkt Kardiologie und Angiologie, Charité Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany
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Effects of dietary supplementation with the green tea polyphenol epigallocatechin-3-gallate on insulin resistance and associated metabolic risk factors: randomized controlled trial. Br J Nutr 2008; 101:886-94. [PMID: 18710606 DOI: 10.1017/s0007114508047727] [Citation(s) in RCA: 183] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Animal evidence indicates that green tea may modulate insulin sensitivity, with epigallocatechin-3-gallate (EGCG) proposed as a likely health-promoting component. The purpose of this study was to investigate the effect of dietary supplementation with EGCG on insulin resistance and associated metabolic risk factors in man. Overweight or obese male subjects, aged 40-65 years, were randomly assigned to take 400 mg capsules of EGCG (n 46) or the placebo lactose (n 42), twice daily for 8 weeks. Oral glucose tolerance testing and measurement of metabolic risk factors (BMI, waist circumference, percentage body fat, blood pressure, total cholesterol, LDL-cholesterol, HDL-cholesterol, TAG) was conducted pre- and post-intervention. Mood was evaluated weekly using the University of Wales Institute of Science and Technology mood adjective checklist. EGCG treatment had no effect on insulin sensitivity, insulin secretion or glucose tolerance but did reduce diastolic blood pressure (mean change: placebo - 0.058 (se 0.75) mmHg; EGCG - 2.68 (se 0.72) mmHg; P = 0.014). No significant change in the other metabolic risk factors was observed. The EGCG group also reported feeling in a more positive mood than the placebo group across the intervention period (mean score for hedonic tone: EGCG, 29.11 (se 0.44); placebo, 27.84 (se 0.46); P = 0.048). In conclusion, regular intake of EGCG had no effect on insulin resistance but did result in a modest reduction in diastolic blood pressure. This antihypertensive effect may contribute to some of the cardiovascular benefits associated with habitual green tea consumption. EGCG treatment also had a positive effect on mood. Further studies are needed to confirm the findings and investigate their mechanistic basis.
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Kuriyama S. The relation between green tea consumption and cardiovascular disease as evidenced by epidemiological studies. J Nutr 2008; 138:1548S-1553S. [PMID: 18641205 DOI: 10.1093/jn/138.8.1548s] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Although substantial evidence from in vitro and animal studies indicates that green tea preparations inhibit cardiovascular disease processes, the possible protective role of green tea consumption against this disease in humans remains unclear. We conducted a population-based prospective cohort study (the Ohsaki Study) to examine the association between green tea consumption and mortality from cardiovascular disease (CVD), cancer, and all causes with 40,530 persons in Miyagi prefecture, in northern Japan. Previously published work has shown that green tea consumption was inversely associated with mortality from CVD and all causes. The inverse association of mortality from CVD was more pronounced in women (P = 0.08 for interaction with sex). In women, the multivariate hazard ratios (95% confidence intervals) of CVD mortality across increasing green tea consumption categories were 1.00, 0.84 (0.63-1.12), 0.69 (0.52-0.93), 0.69 (0.53-0.90) (P for trend = 0.004). Within CVD mortality, the stronger inverse association was observed for stroke mortality. Because our observational study has found the inverse association, I report here the results of a review of epidemiological evidence from randomized controlled trials (RCT) of the association between green tea or green tea extracts and CVD risk profiles. More than half of the RCT have demonstrated the beneficial effects of green tea on CVD risk profiles. These results from RCT suggest a plausible mechanism for the beneficial effects of green tea and provide substantial support for our observations.
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Affiliation(s)
- Shinichi Kuriyama
- Division of Epidemiology, Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
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