1
|
Yazdanpanah Z, Salehi-Abargouei A, Mozaffari Z, Hemayati R. The effect of green tea ( Camellia sinensis) on lipid profiles and renal function in people with type 2 diabetes and nephropathy: a randomized controlled clinical trial. Front Nutr 2023; 10:1253275. [PMID: 38162524 PMCID: PMC10755896 DOI: 10.3389/fnut.2023.1253275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 11/27/2023] [Indexed: 01/03/2024] Open
Abstract
Introduction Diabetic nephropathy is one of the most important microvascular complications of diabetes. Despite the modern treatments, herbs or medicinal plants have gained wide attention. One of these herbs is green tea (Camellia sinensis), which may have an impact on renal function, lipid profiles, and HbA1c. However, the evidence for this is unclear and limited. The present study aimed to evaluate the effect of different doses of green tea on these parameters in type 2 diabetes patients (T2DM) with nephropathy. Methods Sixty-six individuals with T2DM nephropathy (aged 30-70 years) were randomly assigned to receive three cups of green tea/day (n = 22), two cups of green tea/day (n = 22), and the control group (n = 22) for 12 weeks. Lipid profiles, glycated hemoglobin A1c (HbA1c), and renal markers were measured before and after intervention. Data were analyzed using SPSS software version 23. One-way analysis of variance (ANOVA), least significant difference (LSD) post hoc, and analysis of covariance were used to compare quantitative variables. Results In total, 64 participants completed the study. Consuming three cups of infusion green tea per day (7.5 gr) led to a significant reduction in serum levels of total cholesterol (p = 0.009) and HbA1c (p = 0.006) and increased in high-density lipoprotein cholesterol (HDL-C) (p = 0.02) compared with the control group who did not drink green tea. However, no significant differences were observed for other variables. Conclusion In general, it was found that drinking three cups of green tea infusion (7.5 gr) per day produced beneficial effects on some lipid profiles and HbA1c without any adverse effects on renal function in patients with T2DM nephropathy. More studies are needed to fully elucidate these findings. Clinical trial registration Iranian Registry of Clinical Trials (www.irct.ir) under registry number: IRCT2014020114538N2.
Collapse
Affiliation(s)
- Zeinab Yazdanpanah
- Research Center for Food Hygiene and Safety, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
- Department of Nutrition, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Amin Salehi-Abargouei
- Research Center for Food Hygiene and Safety, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
- Department of Nutrition, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
- Yazd Cardiovascular Research Center, Non-communicable Diseases Research Institute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Zohre Mozaffari
- Department of Internal Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Roya Hemayati
- Department of Internal Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
- Diabetes Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| |
Collapse
|
2
|
Yu J, Zhang K, Wang Y, Zhai X, Wan X. Flavor perception and health benefits of tea. ADVANCES IN FOOD AND NUTRITION RESEARCH 2023; 106:129-218. [PMID: 37722772 DOI: 10.1016/bs.afnr.2023.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/20/2023]
Abstract
As one of the most consumed non-alcoholic beverages in the world, tea is acclaimed for its pleasant flavor and various health benefits. Different types of tea present a distinctive flavor and bioactivity due to the changes in the composition and proportion of respective compounds. This article aimed to provide a more comprehensive understanding of tea flavor (including aroma and taste) and the character of tea in preventing and alleviating diseases. The recent advanced modern analytical techniques for revealing flavor components in tea, including enrichment, identification, quantitation, statistics, and sensory evaluation methodologies, were summarized in the following content. Besides, the role of tea in anti-cancer, preventing cardiovascular disease and metabolic syndrome, anti-aging and neuroprotection, and regulating gut microbiota was also listed in this article. Moreover, questions and outlooks were mentioned to objectify tea products' flavor quality and health benefits on a molecular level and significantly promote our understanding of the comprehensive value of tea as a satisfactory health beverage in the future.
Collapse
Affiliation(s)
- Jieyao Yu
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, PR China; International Joint Laboratory on Tea Chemistry and Health Effects of Ministry of Education, Anhui Agricultural University, Hefei, PR China
| | - Kangyi Zhang
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, PR China; International Joint Laboratory on Tea Chemistry and Health Effects of Ministry of Education, Anhui Agricultural University, Hefei, PR China
| | - Yijun Wang
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, PR China; International Joint Laboratory on Tea Chemistry and Health Effects of Ministry of Education, Anhui Agricultural University, Hefei, PR China
| | - Xiaoting Zhai
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, PR China; International Joint Laboratory on Tea Chemistry and Health Effects of Ministry of Education, Anhui Agricultural University, Hefei, PR China
| | - Xiaochun Wan
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, PR China; International Joint Laboratory on Tea Chemistry and Health Effects of Ministry of Education, Anhui Agricultural University, Hefei, PR China.
| |
Collapse
|
3
|
Patanè GT, Putaggio S, Tellone E, Barreca D, Ficarra S, Maffei C, Calderaro A, Laganà G. Catechins and Proanthocyanidins Involvement in Metabolic Syndrome. Int J Mol Sci 2023; 24:ijms24119228. [PMID: 37298181 DOI: 10.3390/ijms24119228] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 05/19/2023] [Accepted: 05/22/2023] [Indexed: 06/12/2023] Open
Abstract
Recent studies on natural antioxidant compounds have highlighted their potentiality against various pathological conditions. The present review aims to selectively evaluate the benefits of catechins and their polymeric structure on metabolic syndrome, a common disorder characterized by a cluster of three main risk factors: obesity, hypertension, and hyperglycemia. Patients with metabolic syndrome suffer chronic low inflammation state and oxidative stress both conditions effectively countered by flavanols and their polymers. The mechanism behind the activity of these molecules has been highlighted and correlated with the characteristic features present on their basic flavonoidic skelethon, as well as the efficient doses needed to perform their activity in both in vitro and in vivo studies. The amount of evidence provided in this review offers a starting point for flavanol dietary supplementation as a potential strategy to counteract several metabolic targets associated with metabolic syndrome and suggests a key role of albumin as flavanol-delivery system to the different target of action inside the organism.
Collapse
Affiliation(s)
- Giuseppe Tancredi Patanè
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Stefano Putaggio
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Ester Tellone
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Davide Barreca
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Silvana Ficarra
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Carlo Maffei
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Antonella Calderaro
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Giuseppina Laganà
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy
| |
Collapse
|
4
|
Association between Green Tea Consumption and Abdominal Obesity Risk in Middle-Aged Korean Population: Findings from the Korean Genome and Epidemiology Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19052735. [PMID: 35270427 PMCID: PMC8910422 DOI: 10.3390/ijerph19052735] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/11/2022] [Accepted: 02/18/2022] [Indexed: 12/10/2022]
Abstract
The prevalence of general and abdominal obesity is increasing with rapid economic growth and the westernization of dietary habits in Korea, especially in the middle-aged population. Data were obtained from the Korean Genome and Epidemiology Study (KoGES), which recruited 10,030 participants between the ages of 40 and 69 years. Information on green tea consumption was obtained from the food frequency questionnaire and categorized as none, <1 cup, between 1 and <4 cups, and ≥4 cups. Multivariable logistic regression models were used to estimate the ORs and 95% CIs to examine any possible associations between green tea consumption and the risk of abdominal obesity after controlling for potential confounders. High consumption of green tea was associated with a 44% lower odds ratio for abdominal obesity (none vs. ≥4 cups/week: OR, 0.56; 95% CI 0.41-0.78; p for trend = 0.001). When stratified by sex, an inverse association between green tea consumption and abdominal obesity was observed only in women (none vs. ≥4 cups/week: OR, 0.71; 95% CI 0.57−0.88; p for trend = 0.004). No significant association was found among men. Our findings indicate that green tea consumption has beneficial effects in the prevention of abdominal obesity in middle-aged Korean women.
Collapse
|
5
|
Gogga P, Szałajda M, Janczy A. Green tea and obesity: Effects of catechins on the
energetic metabolism. POSTEP HIG MED DOSW 2021. [DOI: 10.5604/01.3001.0014.8498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Obesity is a metabolic disease which has now reached epidemic proportions, becoming a major
health, social, and economic problem worldwide. Untreated obesity is associated with decreased
quality of life and is a significant risk factor for the development of other serious health problems,
such as diabetes and cardiovascular diseases. For this reason, new approaches to prevent
excess body mass and to support its reduction if necessary are being examined. Catechins extracted
from green tea – especially epigallocatechin gallate (EGCG) – are one of the most widely
investigated biologically active substances. In addition to the antioxidant, anti-inflammatory,
and anticarcinogenic properties of the catechins, they also exhibit a role in maintaining normal
fat mass and body mass. There are numerous research studies showing that regular green tea
consumption is associated with lower body mass, BMI, and waist circumference. In vitro and
animal experiments confirm beneficial effects of catechins on the energetic metabolism. These
compounds lower lipid and carbohydrates absorption in the intestine. Additionally, they affect
the energetic metabolism, lowering the rate of lipogenesis and adipogenesis, while stimulating
lipolysis and fatty acid oxidation, and increasing energy expenditure. Moreover, it has been established that green tea catechins have an effect on the glucose uptake in the insulin-dependent
manner – by GLUT4. The aim of the following paper was to review and summarize the literature
data concerning the role of green tea catechins in the prevention and treatment of obesity.
Collapse
Affiliation(s)
- Patrycja Gogga
- Zakład Biochemii Żywienia, Wydział Nauk o Zdrowiu z Instytutem Medycyny Morskiej i Tropikalnej, Gdański Uniwersytet Medyczny
| | - Monika Szałajda
- Zakład Biochemii Żywienia, Wydział Nauk o Zdrowiu z Instytutem Medycyny Morskiej i Tropikalnej, Gdański Uniwersytet Medyczny
| | - Agata Janczy
- Zakład Biochemii Żywienia, Wydział Nauk o Zdrowiu z Instytutem Medycyny Morskiej i Tropikalnej, Gdański Uniwersytet Medyczny
| |
Collapse
|
6
|
Chávez-Castillo M, Nuñez V, Rojas M, Ortega Á, Durán P, Pirela D, Marquina M, Cano C, Chacín M, Velasco M, Rojas-Quintero J, Bermúdez V. Exploring Phytotherapeutic Alternatives for Obesity, Insulin Resistance and Diabetes Mellitus. Curr Pharm Des 2021; 26:4430-4443. [PMID: 32611293 DOI: 10.2174/1381612826666200701205132] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 05/29/2020] [Indexed: 11/22/2022]
Abstract
At present, the pathologic spectrum of obesity-insulin resistance (IR)-diabetes mellitus (DM) represents not only a pressing matter in public health but also a paramount object of study in biomedical research, as they constitute major risk factors for cardiovascular disease (CVD), and other chronic non-communicable diseases (NCD). Phytotherapy, the use of medicinal herbs (MH) with treatment purposes, offers a wide array of opportunities for innovation in the management of these disorders; mainly as pharmacological research on small molecules accumulates. Several MH has displayed varied mechanisms of action relevant to the pathogenesis of obesity, IR and DM, including immunological and endocrine modulation, reduction of inflammation and oxidative stress (OS), regulation of appetite, thermogenesis and energy homeostasis, sensitisation to insulin function and potentiation of insulin release, among many others. However, the clinical correlates of these molecular phenomena remain relatively uncertain, with only a handful of MH boasting convincing clinical evidence in this regard. This review comprises an exploration of currently available preclinical and clinical research on the role of MH in the management of obesity, IR, and DM.
Collapse
Affiliation(s)
- Mervin Chávez-Castillo
- Psychiatric Hospital of Maracaibo, Maracaibo, Venezuela,Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo, Venezuela
| | - Victoria Nuñez
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo, Venezuela
| | - Milagros Rojas
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo, Venezuela
| | - Ángel Ortega
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo, Venezuela
| | - Pablo Durán
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo, Venezuela
| | - Daniela Pirela
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo, Venezuela
| | - María Marquina
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo, Venezuela
| | - Clímaco Cano
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo, Venezuela
| | - Maricarmen Chacín
- Universidad Simón Bolívar, Facultad de Ciencias de la Salud, Barranquilla, Colombia
| | - Manuel Velasco
- Clinical Pharmacology Unit, José María Vargas School of Medicine, Central University of Venezuela, Caracas-Venezuela
| | - Joselyn Rojas-Quintero
- Pulmonary and Critical Care Medicine Department, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Valmore Bermúdez
- Universidad Simón Bolívar, Facultad de Ciencias de la Salud, Barranquilla, Colombia
| |
Collapse
|
7
|
Igho-Osagie E, Cara K, Wang D, Yao Q, Penkert LP, Cassidy A, Ferruzzi M, Jacques PF, Johnson EJ, Chung M, Wallace T. Short-Term Tea Consumption Is Not Associated with a Reduction in Blood Lipids or Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Nutr 2020; 150:3269-3279. [PMID: 33188386 DOI: 10.1093/jn/nxaa295] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 06/26/2020] [Accepted: 09/09/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND A recent systematic review of epidemiological evidence suggests that higher amounts of tea intake are associated with lower risks of cardiovascular disease (CVD) incidence and mortality. OBJECTIVES Our study objective was to assess mechanisms by which tea consumption may influence CVD risks. METHODS A systematic review and meta-analysis was conducted to investigate the effects of green and/or black tea consumption (≥4 wk) on systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol, LDL cholesterol, HDL cholesterol, and triglyceride (TG) in healthy populations and among at-risk adults (analyzed separately) with metabolic syndrome, prediabetes, and hypercholesterolemia. The Grading of Recommendations Assessment, Development and Evaluation approach was used to rate the strength of evidence (SoE). RESULTS A total of 14 unique RCTs which randomly assigned 798 participants to either green tea, black tea, or placebo controls were included in our analyses. Intervention durations ranged from 4 to 24 wk (mean: 7.4 wk). Individual studies were judged as moderate to high quality based on risk of bias assessments. SoE was low to moderate owing to low sample sizes and insufficient power for most included studies to observe changes in the measured CVD biomarkers. Meta-analyses showed no significant effects of tea consumption on SBP, DBP, total cholesterol, LDL cholesterol, HDL cholesterol, and TG in healthy and at-risk adults (i.e., adults with obesity, prediabetes, borderline hypercholesterolemia, and metabolic syndrome). CONCLUSIONS Short-term (4-24 wk) tea consumption does not appear to significantly affect blood pressure or lipids in healthy or at-risk adults, although the evidence is limited by insufficient power to detect changes in these CVD biomarkers. High-quality RCTs with longer durations and sufficient sample sizes are needed to fully elucidate the effects of tea. This systematic review was registered at www.crd.york.ac.uk/prospero/ as CRD42020134513.
Collapse
Affiliation(s)
- Ebuwa Igho-Osagie
- Department of Public Health and Community Medicine, School of Medicine, Tufts University, Boston, MA, USA
| | - Kelly Cara
- Department of Public Health and Community Medicine, School of Medicine, Tufts University, Boston, MA, USA.,Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA
| | - Deena Wang
- D&V Systematic Evidence Review Consulting, LLC, Bronx, NY, USA
| | - Qisi Yao
- Department of Public Health and Community Medicine, School of Medicine, Tufts University, Boston, MA, USA
| | - Laura P Penkert
- Department of Public Health and Community Medicine, School of Medicine, Tufts University, Boston, MA, USA.,Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA
| | - Aedin Cassidy
- Department of Nutrition and Preventive Medicine, Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Mario Ferruzzi
- Plants for Human Health Institute, North Carolina State University, Kannapolis, NC, USA
| | - Paul F Jacques
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA
| | - Elizabeth J Johnson
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA
| | - Mei Chung
- Department of Public Health and Community Medicine, School of Medicine, Tufts University, Boston, MA, USA
| | - Taylor Wallace
- Department of Nutrition and Food Studies, George Mason University, Fairfax, VA, USA.,Think Healthy Group, Washington, DC, USA
| |
Collapse
|
8
|
Lin Y, Shi D, Su B, Wei J, Găman MA, Sedanur Macit M, Borges do Nascimento IJ, Guimaraes NS. The effect of green tea supplementation on obesity: A systematic review and dose-response meta-analysis of randomized controlled trials. Phytother Res 2020; 34:2459-2470. [PMID: 32372444 DOI: 10.1002/ptr.6697] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 03/03/2020] [Accepted: 03/22/2020] [Indexed: 12/17/2022]
Abstract
The effects of green tea (GT) in obese subjects have been evaluated in different studies, but no consensus has been obtained due to the heterogeneity of the results. The dosage, the type of extract, and the duration of the intervention are the main contributors to the heterogeneity of the results. Therefore, the present systematic review and meta-analysis aimed to evaluate the efficacy and dose-response relationship of GT. Several databases were searched from inception to September 2019 to identify clinical trials that examined the influence of GT supplements on obesity indices in humans. Combined results using the random-effects model indicated that body weight (WMD: -1.78 kg, 95% CI: -2.80, -0.75, p = .001) and body mass index (BMI) (WMD: -0.65 kg/m2 , 95% CI: -1.04, -0.25, p = .001) did change significantly following GT administration. The reduction in waist circumference (WC) after GT consumption was significant in subjects in trials employing GT ≥800 mg/day (WMD: -2.06 cm) and with a treatment duration <12 weeks (WMD: -2.39 cm). Following the dose-response evaluation, GT intake did alter body weight, with a more important reduction when the GT dosage was <500 mg/day and the treatment duration was of 12 weeks. The results of present meta-analysis study support the use of GT for the improvement of obesity indices. Thus, we suggest that the use of GT can be combined with a balanced and healthy diet and regular physical exercise in the management of obese patients.
Collapse
Affiliation(s)
- Ying Lin
- Department of Endocrinology, Jinan Municipal Hospital of Traditional Chinese Medicine, Jinan City, Shandong Province, China
| | - Dianfeng Shi
- Department of Internal Medicine, Jinan Central Hospital, Jinan, Shandong Province, China
| | - Bo Su
- Department of General Internal Medicine, Xiyuan Hospital China Academy of Chinese Medical Sciences, Beijing, China
| | - Jing Wei
- Department of Endocrinology, Jinan Municipal Hospital of Traditional Chinese Medicine, Jinan City, Shandong Province, China
| | - Mihnea-Alexandru Găman
- "CarolDavila" University of Medicine and Pharmacy, Bucharest, Romania.,Center of Hematology and Bone Marrow Transplantation, Fundeni Clinical Institute, Bucharest, Romania
| | - Melahat Sedanur Macit
- Department of Nutrition and Dietetics, Ondokuz Mayis University, Faculty of Health Sciences, Samsun, Turkey
| | | | - Nathalia Sernizon Guimaraes
- University Hospital and School of Medicine, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| |
Collapse
|
9
|
Xu R, Yang K, Ding J, Chen G. Effect of green tea supplementation on blood pressure: A systematic review and meta-analysis of randomized controlled trials. Medicine (Baltimore) 2020; 99:e19047. [PMID: 32028419 PMCID: PMC7015560 DOI: 10.1097/md.0000000000019047] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Although evidence from animal and observational studies has supported the beneficial effects of green tea intake for lowering blood pressure (BP), randomized placebo-controlled trials (RCTs) have yielded conflicting results. In this meta-analysis of RCTs, we aimed to assess the effects of green tea supplementation on measures of BP control. METHODS The PubMed, Embase, and Cochrane Library databases were electronically searched from inception to August 2019 for all relevant studies. The results were pooled using the generic inverse-variance method with random-effects weighting and expressed as mean differences (MDs) with 95% confidence intervals (CIs). The quality of studies was assessed using the Jadad score. Publication bias was evaluated using funnel plots, Egger test, and Begg test. RESULTS Twenty-four trials with 1697 subjects were included in the meta-analysis. The pooled results showed that green tea significantly lowered systolic BP (SBP; MD: -1.17 mm Hg; 95%CI: -2.18 to -0.16mm Hg; P = .02) and diastolic BP (DBP; MD: -1.24 mm Hg; 95%CI:-2.07 to -0.40mm Hg; P = .004). Significant heterogeneity was found for both SBP (I = 43%) and DBP (I = 57%). In addition, no evidence of significant publication bias was found from funnel plots or Egger test (P = .674 and P = .270 for SBP and DBP, respectively). CONCLUSION Overall, green tea significantly reduced SBP and DBP over the duration of the short-term trials. Larger and longer-term trials are needed to further investigate the effects of green tea supplementation on BP control and clinical events.
Collapse
Affiliation(s)
| | - Ke Yang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P.R. China
| | - Jie Ding
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P.R. China
| | - Guangzhi Chen
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P.R. China
| |
Collapse
|
10
|
Payab M, Hasani-Ranjbar S, Shahbal N, Qorbani M, Aletaha A, Haghi-Aminjan H, Soltani A, Khatami F, Nikfar S, Hassani S, Abdollahi M, Larijani B. Effect of the herbal medicines in obesity and metabolic syndrome: A systematic review and meta-analysis of clinical trials. Phytother Res 2019; 34:526-545. [PMID: 31793087 DOI: 10.1002/ptr.6547] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 09/18/2019] [Accepted: 10/24/2019] [Indexed: 12/12/2022]
Abstract
Obesity is a medical situation in which excess body fat has gathered because of imbalance between energy intake and energy expenditure. In spite of the fact that the variety of studies are available for obesity treatment and management, its "globesity" still remains a big challenge all over the world. The current systematic review and meta-analysis aimed to evaluate the efficacy, safety, and mechanisms of effective herbal medicines in the management and treatment of obesity and metabolic syndrome in human. We systematically searched all relevant clinical trials via Web of Science, Scopus, PubMed, and the Cochrane database to assess the effects of raw or refined products derived from plants or parts of plants on obesity and metabolic syndrome in overweight and obesity adult subjects. All studies conducted by the end of May 2019 were considered in the systematic review. Data were extracted independently by two experts. The quality assessment was assessed using Consolidated Standards of Reporting Trials checklist. The main outcomes were anthropometric indices and metabolic syndrome components. Pooled effect of herbal medicines on obesity and metabolic syndrome were presented as standardized mean difference (SMD) and 95% confidence interval (CI). A total of 279 relevant clinical trials were included. Herbals containing green tea, Phaseolus vulgaris, Garcinia cambogia, Nigella sativa, puerh tea, Irvingia gabonensis, and Caralluma fimbriata and their active ingredients were found to be effective in the management of obesity and metabolic syndrome. In addition, C. fimbriata, flaxseed, spinach, and fenugreek were able to reduce appetite. Meta-analysis showed that intake of green tea resulted in a significant improvement in weight ([SMD]: -0.75 [-1.18, -0.319]), body mass index ([SMD]: -1.2 [-1.82, -0.57]), waist circumference ([SMD]: -1.71 [-2.66, -0.77]), hip circumference ([SMD]: -0.42 [-1.02, -0.19]), and total cholesterol, ([SMD]: -0.43 [-0.77, -0.09]). In addition, the intake of P. vulgaris and N. sativa resulted in a significant improvement in weight ([SMD]: -0.88, 95 % CI: [-1.13, -0.63]) and triglyceride ([SMD]: -1.67, 95 % CI: [-2.54, -0.79]), respectively. High quality trials are still needed to firmly establish the clinical efficacy of the plants in obesity and metabolic syndrome.
Collapse
Affiliation(s)
- Moloud Payab
- Obesity and Eating Habits Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Shirin Hasani-Ranjbar
- Obesity and Eating Habits Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Nazila Shahbal
- Non-Communicable Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Mostafa Qorbani
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.,Non-communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran
| | - Azadeh Aletaha
- Evidence Based Medicine Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of medical Sciences, Tehran, Iran
| | - Hamed Haghi-Aminjan
- Pharmaceutical Science Research Center, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Akbar Soltani
- Evidence Based Medicine Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of medical Sciences, Tehran, Iran
| | - Fatemeh Khatami
- Chronic Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Shekoufeh Nikfar
- Department of Pharmacoeconomics and Pharmaceutical Administration, Faculty of Pharmacy, and Evidence-based Evaluation of Cost-Effectiveness and Clinical Outcomes Group, Pharmaceutical Science Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran
| | - Shokoufeh Hassani
- Toxicology and Diseases Group (TDG), Pharmaceutical Science Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS), and Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Abdollahi
- Toxicology and Diseases Group (TDG), Pharmaceutical Science Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS), and Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Bagher Larijani
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| |
Collapse
|
11
|
Li X, Wang W, Hou L, Wu H, Wu Y, Xu R, Xiao Y, Wang X. Does tea extract supplementation benefit metabolic syndrome and obesity? A systematic review and meta-analysis. Clin Nutr 2019; 39:1049-1058. [PMID: 31174941 DOI: 10.1016/j.clnu.2019.05.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 04/23/2019] [Accepted: 05/16/2019] [Indexed: 01/03/2023]
Abstract
BACKGROUND Given the global epidemic of obesity, numerous strategies have been employed in the management of metabolic syndrome (MS) in this population. A meta-analysis was designed in the present investigation to evaluate the benefits of tea extract (TE) supplementation in MS in obesity. METHODS We conducted searches of published literature in MEDLINE, PsycINFO, Scopus, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases from inception in 1985 to May 2017. Randomized controlled trials (RCTs) which studied TE consumption in obesity with MS were analyzed. Results were summarized using weighted mean differences (WMDs), standardized mean differences (SMDs) or odds ratio (OR) by suitable effect model. RESULTS Sixteen eligible randomized controlled trials, including 1090 subjects were identified. Benefits were demonstrated on reduction of Body Mass Index (BMI) (SMD, -0.27; 95% CI, -0.40 to -0.15, P < 0.0001) and blood glucose (SMD, -0.22; 95% CI, -0.34 to -0.10, P = 0.0003), and increasing high-density lipoprotein (HDL) (SMD, 0.18; 95% CI, 0.01 to 0.35, P = 0.03). Limited benefits without significance were observed on blood pressure and other anthropometric, cholesterol, and biochemistry outcomes. All-cause adverse events were minimal (0.99; 95% CI: 0.55, 1.77, P = 0.97). CONCLUSIONS This meta-analysis suggests that consumption of TE supplementation in the obese with MS has beneficial effects on improvement of lipid and glucose metabolism, as well as in the facilitation of weight loss.
Collapse
Affiliation(s)
- Xiumin Li
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, PR China
| | - Wen Wang
- Department of Radiology & Functional and Molecular Imaging Key Lab of Shaanxi Province, Tangdu Hospital, Fourth Military Medical University, 569 Xinsi Road, Xi'an, 710038, Shaanxi, PR China
| | - Liming Hou
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, PR China
| | - Huanghui Wu
- Department of Anesthesiology, Fuzhou General Hospital of Nanjing Military Region, Fuzhou 350025, PR China
| | - Yongjie Wu
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, PR China
| | - Rong Xu
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, PR China
| | - Yuan Xiao
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, PR China
| | - Xiaoming Wang
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, PR China.
| |
Collapse
|
12
|
Wharton S, Bonder R, Jeffery A, Christensen RAG. The safety and effectiveness of commonly-marketed natural supplements for weight loss in populations with obesity: A critical review of the literature from 2006 to 2016. Crit Rev Food Sci Nutr 2019; 60:1614-1630. [PMID: 30896252 DOI: 10.1080/10408398.2019.1584873] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Objective: To evaluate the evidence published from 2006 to 2016 on the effectiveness and safety of commonly used natural supplements for weight loss in individuals with obesity.Methods: Amazon and Google were searched for names of mono-agent natural supplements marketed for weight loss and a list of the 10 supplements was created. Google Scholar, Pubmed, Science Direct, and the Cochrane Library were searched for articles that met inclusion.Results: At least one article was published on the effectiveness or safety of bitter orange, capsinoid, carnitine, chromium picolinate, Coleus forskohlii, conjugated linoleic acid, glucomannan, green tea and psyllium for weight loss in populations with obesity from 2006 to 2016. There was insufficient evidence to suggest that the natural supplements examined contribute to significant weight loss, with the exception of perhaps glucomannan in the form of PGX. In general, the majority of side-effects reported were minor to moderate, and gastrointestinal-related. However, in some cases extreme side-effects such as liver and kidney failure were observed.Conclusion: Contrary to popular belief, results of this review suggest that the use of natural supplements for weight loss are unlikely to contribute to meaningful weight loss and in some cases may contribute to harm.
Collapse
Affiliation(s)
- Sean Wharton
- The Wharton Medical Clinic, Toronto, Ontario, Canada.,School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada
| | - Revi Bonder
- School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada
| | - Aaron Jeffery
- The Wharton Medical Clinic, Toronto, Ontario, Canada
| | | |
Collapse
|
13
|
Francini-Pesenti F, Spinella P, Calò LA. Potential role of phytochemicals in metabolic syndrome prevention and therapy. Diabetes Metab Syndr Obes 2019; 12:1987-2002. [PMID: 31632110 PMCID: PMC6778731 DOI: 10.2147/dmso.s214550] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 07/09/2019] [Indexed: 12/20/2022] Open
Abstract
Metabolic syndrome (MetS) is a set of cardiovascular risk factors which severely increases the risk of type II diabetes, renal disease and cardiovascular disease. Over the last decades, the role of dietary bioactive substances in features of MetS has been extensively investigated. Due to their multiple properties, these plant-derived natural compounds have demonstrated to provide positive effects in obesity, diabetes, renal and in cardiovascular disease. Catechins of green tea and caffeine reduce body mass index and waist circumference. Catechins, anthocyanins and proanthocyanidins of cocoa reduce blood pressure and blood glucose. Curcumin and silymarin exert hepatoprotective effects. Monacolins of red yeast rice are effective cholesterol-lowering agents. However, inconsistent or conflicting results have been found in clinical trials when other promising compounds in vitro or in animal studies, such as policosanol, curcumin or silymarin, were used. Low oral bioavailability of substances, ineffective dosages, inadequate treatment duration and insufficient statistical approach may explain the lack of effectiveness observed in some human studies. Further clinical studies are needed to better understand the role of bioactive compounds in the prevention and management of MetS.
Collapse
Affiliation(s)
| | - Paolo Spinella
- Department of Medicine (DIMED), Nutrition Unit, University of Padova-Azienda Ospedaliera, Padova, Italy
| | - Lorenzo A Calò
- Department of Medicine (DIMED), Nephrology, Dialysis and Transplantation Unit, University of Padova-Azienda Ospedaliera, Padova, Italy
- Correspondence: Lorenzo A CalòDepartment of Medicine, Nephrology, Dialysis and Transplantation Unit, University of Padova-Azienda Ospedaliera, Via Giustiniani 2, Padova35128, ItalyTel +39 049 821 3071Fax +39 049 821 7921Email
| |
Collapse
|
14
|
Effects of Coffee and Tea Consumption on Glucose Metabolism: A Systematic Review and Network Meta-Analysis. Nutrients 2018; 11:nu11010048. [PMID: 30591664 PMCID: PMC6356434 DOI: 10.3390/nu11010048] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 12/13/2018] [Accepted: 12/21/2018] [Indexed: 01/04/2023] Open
Abstract
Prospective cohort studies have described an association between coffee or tea consumption and the risk of developing diabetes. However, whether coffee or tea improves glucose metabolism remains uncertain. We investigated the effect of coffee and tea on glucose metabolism by conducting a systematic review and meta-analysis of randomized controlled trials. Electronic databases were searched for articles published up 19 February 2017. The primary endpoint was the mean difference in post-intervention fasting blood glucose (FBG) levels between the groups. Of 892 citations screened, 27 studies (1898 participants) were included in our meta-analysis. A network meta-analysis suggested that green tea, but not caffeinated/decaffeinated coffee or black tea, may reduce FBG levels, compared with placebo/water (−2.10 mg/dL; 95% confidence interval (CI), −3.96 to −0.24 mg/dL; p = 0.03; moderate quality of evidence). In a subgroup analysis, the effect of green tea on FBG levels was statistically significant only in studies with a mean age of < 55-years-old or Asian-based studies. The oolong tea group also showed a significant decrease in FBG, but the quality of evidence was very low. In conclusion, green tea consumption might decrease FBG levels, especially in < 55-year-olds or Asian-based populations.
Collapse
|
15
|
Effect of green tea, caffeine and capsaicin supplements on the anthropometric indices: A meta-analysis of randomized clinical trials. J Funct Foods 2018. [DOI: 10.1016/j.jff.2018.04.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
|
16
|
Yuan F, Dong H, Fang K, Gong J, Lu F. Effects of green tea on lipid metabolism in overweight or obese people: A meta-analysis of randomized controlled trials. Mol Nutr Food Res 2017. [PMID: 28636182 DOI: 10.1002/mnfr.201601122] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
SCOPE The effects of green tea on lipid metabolism were inconsistent. The objective of this meta-analysis was to evaluate the effects of green tea on lipid metabolism in overweight or obese people. METHODS AND RESULTS We searched randomized controlled trials (RCTs) comparing green tea with a control on lipid metabolism on PUBMED and WEB OF SCIENCE (January 1990 to September 2016), COCHRANE and EMBASE (updated to October 2016), and the Chinese databases CNKI, WanFang and CBMD. Twenty-one articles studying 1704 overweight or obese subjects were selected for this meta-analysis. The pooled results demonstrated that green tea significantly decreased plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL) levels in overweight or obese people. The weighted mean difference was -3.38 mg/dl for TC (95% CI: -6.42, -0.33 mg/dL) and -5.29 mg/dL for LDL (95% CI: -7.92, -2.6 6 mg/dL), respectively. Green tea intake, however, showed no effect on plasma triglyceride (TG) and high-density lipoprotein cholesterol(HDL) levels in overweight or obese people with a relatively high heterogeneity. CONCLUSION The meta-analysis shows that drinking green tea can lower plasma TC and LDL levels significantly. Nevertheless, green tea's effect on plasma TG and HDL must be further evaluated by additional high-quality and large-scale RCTs.
Collapse
Affiliation(s)
- Fen Yuan
- Institute of Integrated Traditional Chinese and Wertern Medicine, Tongji Hospital, Tongji Medical College, HuaZhong University of Science and Technology, Wuhan, Hubei, China
| | - Hui Dong
- Institute of Integrated Traditional Chinese and Wertern Medicine, Tongji Hospital, Tongji Medical College, HuaZhong University of Science and Technology, Wuhan, Hubei, China
| | - Ke Fang
- Institute of Integrated Traditional Chinese and Wertern Medicine, Tongji Hospital, Tongji Medical College, HuaZhong University of Science and Technology, Wuhan, Hubei, China
| | - Jing Gong
- Institute of Integrated Traditional Chinese and Wertern Medicine, Tongji Hospital, Tongji Medical College, HuaZhong University of Science and Technology, Wuhan, Hubei, China
| | - Fuer Lu
- Institute of Integrated Traditional Chinese and Wertern Medicine, Tongji Hospital, Tongji Medical College, HuaZhong University of Science and Technology, Wuhan, Hubei, China
| |
Collapse
|
17
|
Yu J, Song P, Perry R, Penfold C, Cooper AR. The Effectiveness of Green Tea or Green Tea Extract on Insulin Resistance and Glycemic Control in Type 2 Diabetes Mellitus: A Meta-Analysis. Diabetes Metab J 2017; 41:251-262. [PMID: 28868822 PMCID: PMC5583402 DOI: 10.4093/dmj.2017.41.4.251] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 08/09/2017] [Indexed: 01/17/2023] Open
Abstract
Green tea or green tea extract (GT/GTE) has been demonstrated to reduce insulin resistance and improve glycemic control. However, evidence for this health beneficial effect is inconsistent. This systematic review evaluated the effect of GT/GTE on insulin resistance and glycemic control in people with pre-diabetes/type 2 diabetes mellitus (T2DM). Ovid MEDLINE, Embase, AMED, Web of Science, and the Cochrane Library were searched up to April 2017 for randomised controlled trials of participants with pre-diabetes or T2DM, where the intervention was GT/GTE. Meta-analysis was performed to assess the standardised mean difference (SMD) in biomarkers of insulin resistance and glycemic control between GT/GTE and placebo groups. Six studies (n=382) were pooled into random-effects meta-analysis. Overall, no differences were found between GT/GTE and the placebo for glycosylated hemoglobin (HbA1c: SMD, -0.32; 95% confidence interval [CI], -0.86 to 0.23), homeostatic model assessment for insulin resistance (HOMA-IR: SMD, 0.10; 95% CI, -0.17 to 0.38), fasting insulin (SMD, -0.25; 95% CI, -0.64 to 0.15), and fasting glucose (SMD, -0.10; 95% CI, -0.50 to 0.30). No evidence support the consumption of GT/GTE could reduce the levels of HbA1c, HOMA-IR, fasting insulin, or fasting glucose in people with pre-diabetes/T2DM. However, the studies included were small and of varying quality.
Collapse
Affiliation(s)
- Jinyue Yu
- Division of Medicine, School of life and Medical Science, University College London, London, UK
| | - Peige Song
- Centre for Population Health Sciences, University of Edinburgh, Edinburgh, UK
| | - Rachel Perry
- NIHR Bristol Biomedical Research Centre, Nutrition Theme, University of Bristol, Bristol, UK
| | - Chris Penfold
- NIHR Bristol Biomedical Research Centre, Nutrition Theme, University of Bristol, Bristol, UK
| | - Ashley R Cooper
- NIHR Bristol Biomedical Research Centre, Nutrition Theme, University of Bristol, Bristol, UK
- Centre for Exercise, Nutrition and Health Sciences, School for Policy Studies, University of Bristol, Bristol, UK.
| |
Collapse
|
18
|
González-Sarrías A, Combet E, Pinto P, Mena P, Dall’Asta M, Garcia-Aloy M, Rodríguez-Mateos A, Gibney ER, Dumont J, Massaro M, Sánchez-Meca J, Morand C, García-Conesa MT. A Systematic Review and Meta-Analysis of the Effects of Flavanol-Containing Tea, Cocoa and Apple Products on Body Composition and Blood Lipids: Exploring the Factors Responsible for Variability in Their Efficacy. Nutrients 2017. [PMCID: PMC5537860 DOI: 10.3390/nu9070746] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Several randomized controlled trials (RCTs) and meta-analyses support the benefits of flavanols on cardiometabolic health, but the factors affecting variability in the responses to these compounds have not been properly assessed. The objectives of this meta-analysis were to systematically collect the RCTs-based-evidence of the effects of flavanol-containing tea, cocoa and apple products on selected biomarkers of cardiometabolic risk and to explore the influence of various factors on the variability in the responses to the consumption of these products. A total of 120 RCTs were selected. Despite a high heterogeneity, the intake of the flavanol-containing products was associated using a random model with changes (reported as standardized difference in means (SDM)) in body mass index (−0.15, p < 0.001), waist circumference (−0.29, p < 0.001), total-cholesterol (−0.21, p < 0.001), LDL-cholesterol (−0.23, p < 0.001), and triacylglycerides (−0.11, p = 0.027), and with an increase of HDL-cholesterol (0.15, p = 0.005). Through subgroup analyses, we showed the influence of baseline-BMI, sex, source/form of administration, medication and country of investigation on some of the outcome measures and suggest that flavanols may be more effective in specific subgroups such as those with a BMI ≥ 25.0 kg/m2, non-medicated individuals or by specifically using tea products. This meta-analysis provides the first robust evidence of the effects induced by the consumption of flavanol-containing tea, cocoa and apple products on weight and lipid biomarkers and shows the influence of various factors that can affect their bioefficacy in humans. Of note, some of these effects are quantitatively comparable to those produced by drugs, life-style changes or other natural products. Further, RCTs in well-characterized populations are required to fully comprehend the factors affecting inter-individual responses to flavanol and thereby improve flavanols efficacy in the prevention of cardiometabolic disorders.
Collapse
Affiliation(s)
- Antonio González-Sarrías
- Research Group on Quality, Safety and Bioactivity of Plant Foods, Campus de Espinardo, Centro de Edafologia y Biologia Aplicada del Segura-Consejo Superior de Investigaciones Científicas (CEBAS-CSIC), P.O. Box 164, 30100 Murcia, Spain
- Correspondence: (A.G.-S.); (M.-T.G.-C.); Tel.: +34-968-396276 (A.G.-S. & M.-T.G.-C.); Fax: +34-968-396213(A.G.-S. & M.-T.G.-C.)
| | - Emilie Combet
- Human Nutrition, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G31 2ER, UK;
| | - Paula Pinto
- Polytechnic Institute of Santarem, Escola Superior Agrária (ESA), Department of Food Technology, Biotechnology and Nutrition, 2001-904 Santarém, Portugal;
| | - Pedro Mena
- Human Nutrition Unit, Department of Food & Drug, University of Parma, 43125 Parma, Italy; (P.M.); (M.D.)
| | - Margherita Dall’Asta
- Human Nutrition Unit, Department of Food & Drug, University of Parma, 43125 Parma, Italy; (P.M.); (M.D.)
| | - Mar Garcia-Aloy
- Biomarkers and Nutrimetabolomic Laboratory, Department of Nutrition, Food Sciences and Gastronomy, University of Barcelona, 08028 Barcelona, Spain;
- CIBER de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, 08028 Barcelona, Spain
| | - Ana Rodríguez-Mateos
- Division of Diabetes and Nutritional Sciences, King’s College London, London SE1 9NH, UK;
| | - Eileen R. Gibney
- Institute of Food and Health, School of Agriculture and Food Science, University College Dublin (UCD), Belfield, Dublin 4, Ireland;
| | - Julie Dumont
- U1167-RID-AGE-Facteurs de risque et Déterminants Moléculaires des Maladies Liées au Vieillissement, University Lille, Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Hospitalier Universitaire (CHU) Lille, Institut Pasteur de Lille, F-59000 Lille, France;
| | - Marika Massaro
- National Research Council (CNR), Institute of Clinical Physiology, 73100 Lecce, Italy;
| | - Julio Sánchez-Meca
- Department of Basic Psychology & Methodology, Faculty of Psychology, University of Murcia, 30100 Murcia, Spain;
| | - Christine Morand
- Institut National de la Recherche Agronomique (INRA), Human Nutrition Unit, Université Clermont Auvergne (UCA), Centre de Recherches en Nutrition Humaine (CRNH) Auvergne, F-63000 Clermont-Ferrand, France;
| | - María-Teresa García-Conesa
- Research Group on Quality, Safety and Bioactivity of Plant Foods, Campus de Espinardo, Centro de Edafologia y Biologia Aplicada del Segura-Consejo Superior de Investigaciones Científicas (CEBAS-CSIC), P.O. Box 164, 30100 Murcia, Spain
- Correspondence: (A.G.-S.); (M.-T.G.-C.); Tel.: +34-968-396276 (A.G.-S. & M.-T.G.-C.); Fax: +34-968-396213(A.G.-S. & M.-T.G.-C.)
| |
Collapse
|
19
|
Ma SB, Zhang R, Miao S, Gao B, Lu Y, Hui S, Li L, Shi XP, Wen AD. Epigallocatechin-3-gallate ameliorates insulin resistance in hepatocytes. Mol Med Rep 2017; 15:3803-3809. [DOI: 10.3892/mmr.2017.6450] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Accepted: 12/19/2016] [Indexed: 11/05/2022] Open
|
20
|
Zhu X, Yang L, Xu F, Lin L, Zheng G. Combination therapy with catechins and caffeine inhibits fat accumulation in 3T3-L1 cells. Exp Ther Med 2016; 13:688-694. [PMID: 28352352 DOI: 10.3892/etm.2016.3975] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 09/27/2016] [Indexed: 02/06/2023] Open
Abstract
Catechins and caffeine, which are green tea components, have a slimming effect; however, the combinational effect of fat metabolism in 3T3-L1 cells remains unclear. In the present study, 3T3-L1 cells were treated with catechins and caffeine in combination, and it was found that combination therapy with catechins and caffeine markedly reduced intracellular fat accumulation, mRNA expression levels of peroxisome proliferator-activated receptor-γ and CCAAT/enhancer-binding protein α in the early stage of cell differentiation were significantly reduced, and mRNA expression of fatty acid synthetase(FAS) andglycerol-3-phosphate dehydrogenase protein expression levels of FAS were downregulated. Noradrenaline-induced lipolysis was enhanced by caffeine, which markedly increased the protein expression of adipose triglyceride lipase and hormone sensitive lipase. These results indicated that combination therapy with catechins and caffeine synergistically inhibited lipid accumulation by regulating the gene and protein expression levels of lipid metabolism-related enzymes. Therefore, catechins and caffeine combination therapy has potential as a functional food that may be used to prevent obesity and lifestyle-associated diseases.
Collapse
Affiliation(s)
- Xiaojuan Zhu
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, P.R. China
| | - Licong Yang
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, P.R. China
| | - Feng Xu
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, P.R. China
| | - Lezhen Lin
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, P.R. China
| | - Guodong Zheng
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, P.R. China
| |
Collapse
|
21
|
Samavat H, Newman AR, Wang R, Yuan JM, Wu AH, Kurzer MS. Effects of green tea catechin extract on serum lipids in postmenopausal women: a randomized, placebo-controlled clinical trial. Am J Clin Nutr 2016; 104:1671-1682. [PMID: 27806972 PMCID: PMC5118731 DOI: 10.3945/ajcn.116.137075] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 09/22/2016] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Green tea has been suggested to improve cardiovascular disease risk factors, including circulating lipid variables. However, current evidence is predominantly based on small, short-term randomized controlled trials conducted in diverse populations. OBJECTIVE The aim of this study was to examine the efficacy and impact of green tea extract (GTE) supplementation high in epigallocatechin gallate (EGCG) on blood lipids in healthy postmenopausal women. DESIGN This was an ancillary study of a double-blind, randomized, placebo-controlled, parallel-arm trial investigating the effects of a GTE supplement containing 1315 mg catechins (843 mg EGCG) on biomarkers of breast cancer risk. Participants were randomly assigned to receive GTE (n = 538) or placebo (n = 537) and were stratified by catechol-O-methyltransferase (COMT) genotype activity (high COMT compared with low or intermediate COMT genotype activity). They consumed either 4 GTE or identical placebo capsules daily for 12 mo. A total of 936 women completed this substudy. Circulating lipid panels including total cholesterol (TC), HDL cholesterol, and triglycerides were measured at baseline and at months 6 and 12. RESULTS Compared with placebo, 1-y supplementation with GTE capsules resulted in a significant reduction in circulating TC (-2.1% compared with 0.7%; P = 0.0004), LDL cholesterol (-4.1% compared with 0.9%; P < 0.0001) and non-HDL cholesterol (-3.1% compared with 0.4%; P = 0.0032). There was no change in HDL-cholesterol concentration, but triglyceride concentrations increased by 3.6% in the GTE group, whereas they decreased by 2.5% in the placebo group (P = 0.046). A significant reduction in TC was observed only among women with high (i.e., ≥200 mg/dL) baseline TC concentrations (P-interaction = 0.01) who consumed GTE capsules. The effect of GTE on the increase in triglycerides was mainly observed among obese women and statin users (P-interaction = 0.06). CONCLUSION Supplementation with GTE significantly reduced circulating TC and LDL-cholesterol concentrations, especially in those with elevated baseline TC concentrations. This trial was registered at clinicaltrials.gov as NCT00917735.
Collapse
Affiliation(s)
- Hamed Samavat
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN
| | - April R Newman
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN
| | - Renwei Wang
- Division of Cancer Control and Population Sciences, University of Pittsburgh Cancer Institute, Pittsburgh, PA
| | - Jian-Min Yuan
- Division of Cancer Control and Population Sciences, University of Pittsburgh Cancer Institute, Pittsburgh, PA
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA; and
| | - Anna H Wu
- Department of Preventive Medicine, University of Southern California Keck School of Medicine, Los Angeles, CA
| | - Mindy S Kurzer
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN;
| |
Collapse
|
22
|
Phenolic compounds of green tea: Health benefits and technological application in food. Asian Pac J Trop Biomed 2016. [DOI: 10.1016/j.apjtb.2016.06.010] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
23
|
Amiot MJ, Riva C, Vinet A. Effects of dietary polyphenols on metabolic syndrome features in humans: a systematic review. Obes Rev 2016; 17:573-86. [PMID: 27079631 DOI: 10.1111/obr.12409] [Citation(s) in RCA: 266] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 02/16/2016] [Accepted: 02/16/2016] [Indexed: 12/13/2022]
Abstract
Dietary polyphenols constitute a large family of bioactive substances potential beneficial effect on metabolic syndrome (MetS). This review summarizes the results of clinical studies on patients with MetS involving the chronic supplementation of a polyphenol-rich diet, foods, extracts or with single phenolics on the features of MetS (obesity, dyslipidemia, blood pressure and glycaemia) and associated complications (oxidative stress and inflammation). Polyphenols were shown to be efficient, especially at higher doses, and there were no specific foods or extracts able to alleviate all the features of MetS. Green tea, however, significantly reduced body mass index and waist circumference and improved lipid metabolism. Cocoa supplementation reduced blood pressure and blood glucose. Soy isoflavones, citrus products, hesperidin and quercetin improved lipid metabolism, whereas cinnamon reduced blood glucose. In numerous clinical studies, antioxidative and anti-inflammatory effects were not significant after polyphenol supplementation in patients with MetS. However, some trials pointed towards an improvement of endothelial function in patients supplemented with cocoa, anthocyanin-rich berries, hesperidin or resveratrol. Therefore, diets rich in polyphenols, such as the Mediterranean diet, which promote the consumption of diverse polyphenol-rich products could be an effective nutritional strategy to improve the health of patients with MetS. © 2016 The Authors. Obesity Reviews published by John Wiley & Sons Ltd on behalf of World Obesity.
Collapse
Affiliation(s)
- M J Amiot
- Unité Mixte de Recherche (UMR) 'Nutrition, Obesity and Risk of Thrombosis', Institut National de la Recherche Agronomique, Paris, France.,Institut National de la Santé et de la Recherche Médicale, Paris, France.,Aix-Marseille Université, Marseille, France
| | - C Riva
- LaPEC, EA4278, Université d'Avignon, Avignon, France
| | - A Vinet
- LaPEC, EA4278, Université d'Avignon, Avignon, France
| |
Collapse
|
24
|
Janssens PLHR, Hursel R, Westerterp-Plantenga MS. Nutraceuticals for body-weight management: The role of green tea catechins. Physiol Behav 2016; 162:83-7. [PMID: 26836279 DOI: 10.1016/j.physbeh.2016.01.044] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 01/20/2016] [Accepted: 01/29/2016] [Indexed: 11/29/2022]
Abstract
Green tea catechins mixed with caffeine have been proposed as adjuvants for maintaining or enhancing energy expenditure and for increasing fat oxidation, in the context of prevention and treatment of obesity. These catechins-caffeine mixtures seem to counteract the decrease in metabolic rate that occurs during weight loss. Their effects are of particular importance during weight maintenance after weight loss. Other metabolic targets may be fat absorption and the gut microbiota composition, but these effects still need further investigation in combination with weight loss. Limitations for the effects of green tea catechins are moderating factors such as genetic predisposition related to COMT-activity, habitual caffeine intake, and ingestion combined with dietary protein. In conclusion, a mixture of green tea catechins and caffeine has a beneficial effect on body-weight management, especially by sustained energy expenditure, fat oxidation, and preservation of fat free body-mass, after energy restriction induced body-weight loss, when taking the limitations into account.
Collapse
Affiliation(s)
- Pilou L H R Janssens
- Department of Human Biology, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, The Netherlands
| | - Rick Hursel
- Department of Human Biology, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, The Netherlands
| | - Margriet S Westerterp-Plantenga
- Department of Human Biology, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, The Netherlands.
| |
Collapse
|
25
|
|
26
|
Short-term weight-centric effects of tea or tea extract in patients with metabolic syndrome: a meta-analysis of randomized controlled trials. Nutr Diabetes 2015; 5:e160. [PMID: 26075637 PMCID: PMC4491851 DOI: 10.1038/nutd.2015.10] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 02/15/2015] [Accepted: 04/08/2015] [Indexed: 01/28/2023] Open
Abstract
To evaluate the weight-centric effect of tea or tea extract in participants with metabolic syndrome (MetS), we performed electronic searches in PubMed, EmBase and the Cochrane Library to identify eligible randomized controlled trials (RCTs) comparing tea or tea extract vs a control group. A direct meta-analysis using random-effects model was conducted to pool the standardized mean difference regarding body mass index (BMI), body weight and waist circumference. Study quality was assessed by using the Jadad scale. Pre-specified subgroup and sensitivity analyses were conducted to explore potential heterogeneity. A total of five RCTs involving 338 adult individuals were included. Given the high heterogeneity observed in the overall pooled analysis, we separated the included subjects into two subgroups. Ingestion of tea or tea extract significantly reduced BMI (subgroup 1: -1.60, 95% confidence interval (CI), -2.05 to -1.14; subgroup 2: -0.40, 95% CI, -0.69 to -0.12) and body weight (subgroup 1: -4.14, 95% CI, -4.85 to -3.43; subgroup 2: -0.35, 95% CI, -0.68 to -0.02). This meta-analysis suggests that tea or tea extract has favorable weight-centric effects in MetS patients. Additional large RCTs specifically designed to evaluate the effect on anthropometric measurements are needed to further confirm these findings.
Collapse
|
27
|
Mota MADL, Landim JSP, Targino TSS, Silva SFRD, Silva SLD, Pereira MRP. Evaluation of the anti-inflammatory and analgesic effects of green tea (Camellia sinensis) in mice. Acta Cir Bras 2015; 30:242-6. [DOI: 10.1590/s0102-865020150040000002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 03/17/2015] [Indexed: 12/13/2022] Open
|
28
|
Grosso G, Stepaniak U, Micek A, Topor-Mądry R, Pikhart H, Szafraniec K, Pająk A. Association of daily coffee and tea consumption and metabolic syndrome: results from the Polish arm of the HAPIEE study. Eur J Nutr 2014; 54:1129-37. [PMID: 25367317 PMCID: PMC4575379 DOI: 10.1007/s00394-014-0789-6] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 09/30/2014] [Indexed: 01/11/2023]
Abstract
Purpose The aim of this study was to evaluate whether daily consumption of coffee and tea was associated with components and prevalence of metabolic syndrome (MetS) in the Polish arm of the Health, Alcohol and Psychosocial factors In Eastern Europe cohort study. Methods A cross-sectional population-based survey including 8,821 adults (51.4 % female) was conducted in Krakow, Poland. Coffee and tea consumption was evaluated using food frequency questionnaires. MetS was defined according to the International Diabetes Federation definition. Linear and logistic regression models were performed to estimate odds ratios and confidence intervals. Results Among high coffee and tea consumers (3 or more cups/day), high prevalence of female gender, young age, medium–high educational and occupational level, high total energy intake, and smoking habit were found. High coffee drinkers had lower BMI, waist circumference, systolic and diastolic blood pressure, triglycerides, and higher HDL cholesterol than those drinking less than 1 cup/day. In contrast, high tea consumers had lower BMI, waist circumference, but not diastolic blood pressure, which was higher than low drinkers. After adjusting for potential confounding factors, both higher coffee and tea consumption were negatively associated with MetS (OR 0.75, 95 % CI 0.66, 0.86 and OR 0.79, 95 % CI 0.67, 0.92, respectively). Among specific components of MetS, high coffee consumption was negatively associated with waist circumference, hypertension, and triglycerides, whereas tea consumption with central obesity and fasting plasma glucose in women, but not in men. Conclusions Coffee and tea consumption was negatively associated with MetS and some of its components.
Collapse
Affiliation(s)
- Giuseppe Grosso
- Department of Clinical and Molecular Biomedicine, Section of Pharmacology and Biochemistry, University of Catania, V.le A. Doria 6, 95125, Catania, Italy. .,Department of Epidemiology and Population Studies, Jagiellonian University Medical College, Kraków, Poland.
| | - Urszula Stepaniak
- Department of Epidemiology and Population Studies, Jagiellonian University Medical College, Kraków, Poland
| | - Agnieszka Micek
- Department of Epidemiology and Population Studies, Jagiellonian University Medical College, Kraków, Poland
| | - Roman Topor-Mądry
- Department of Epidemiology and Population Studies, Jagiellonian University Medical College, Kraków, Poland
| | - Hynek Pikhart
- Department of Epidemiology and Public Health, University College London, London, UK
| | - Krystyna Szafraniec
- Department of Epidemiology and Population Studies, Jagiellonian University Medical College, Kraków, Poland
| | - Andrzej Pająk
- Department of Epidemiology and Population Studies, Jagiellonian University Medical College, Kraków, Poland
| |
Collapse
|
29
|
Onakpoya I, Spencer E, Heneghan C, Thompson M. The effect of green tea on blood pressure and lipid profile: a systematic review and meta-analysis of randomized clinical trials. Nutr Metab Cardiovasc Dis 2014; 24:823-836. [PMID: 24675010 DOI: 10.1016/j.numecd.2014.01.016] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 01/21/2014] [Accepted: 01/22/2014] [Indexed: 01/16/2023]
Abstract
INTRODUCTION Many different dietary supplements are currently marketed for the management of hypertension, but the evidence for effectiveness is mixed. The aim of this systematic review was to evaluate the evidence for or against the effectiveness of green tea (Camellia sinensis) on blood pressure and lipid parameters. METHODS AND RESULTS Electronic searches were conducted in Medline, Embase, Amed, Cinahl and the Cochrane Library to identify relevant human randomized clinical trials (RCTs). Hand searches of bibliographies were also conducted. The reporting quality of included studies was assessed using a checklist adapted from the CONSORT Statement. Two reviewers independently determined eligibility, assessed the reporting quality of the included studies, and extracted the data. As many as 474 citations were identified and 20 RCTs comprising 1536 participants were included. There were variations in the designs of the RCTs. A meta-analysis revealed a significant reduction in systolic blood pressure favouring green tea (MD: -1.94 mmHg; 95% CI: -2.95 to -0.93; I(2) = 8%; p = 0.0002). Similar results were also observed for total cholesterol (MD: -0.13 mmol/l; 95% CI: -0.2 to -0.07; I(2) = 8%; p < 0.0001) and LDL cholesterol (MD: -0.19 mmol/l; 95% CI: -0.3 to -0.09; I(2) = 70%; p = 0.0004). Adverse events included rash, elevated blood pressure, and abdominal discomfort. CONCLUSION Green tea intake results in significant reductions in systolic blood pressure, total cholesterol, and LDL cholesterol. The effect size on systolic blood pressure is small, but the effects on total and LDL cholesterol appear moderate. Longer-term independent clinical trials evaluating the effects of green tea are warranted.
Collapse
Affiliation(s)
- I Onakpoya
- Department of Primary Care Health Sciences, University of Oxford, United Kingdom.
| | - E Spencer
- Department of Primary Care Health Sciences, University of Oxford, United Kingdom
| | - C Heneghan
- Department of Primary Care Health Sciences, University of Oxford, United Kingdom
| | - M Thompson
- Department of Primary Care Health Sciences, University of Oxford, United Kingdom; Department of Family Medicine, University of Washington, Seattle, USA
| |
Collapse
|
30
|
Khalesi S, Sun J, Buys N, Jamshidi A, Nikbakht-Nasrabadi E, Khosravi-Boroujeni H. Green tea catechins and blood pressure: a systematic review and meta-analysis of randomised controlled trials. Eur J Nutr 2014; 53:1299-311. [PMID: 24861099 DOI: 10.1007/s00394-014-0720-1] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 05/13/2014] [Indexed: 12/29/2022]
Abstract
PURPOSE Although previous literature has reported that regular green tea consumption may improve blood pressure, the evidence from these studies is not consistent. The present study systematically reviewed randomised controlled trials and examined the effect of green tea consumption on blood pressure using meta-analysis. METHODS Search of ProQuest, PubMed, Scopus and Cochrane Library (CENTERAL) was conducted, to identify eligible articles. Articles from 1995 to 2013 were included. A random-effect model was chosen to calculate the effect of combined trials. RESULT Thirteen studies were included in the meta-analysis. Green tea consumption significantly changed systolic blood pressure, by -2.08 mm Hg (95% CI -3.06, -1.05), and diastolic blood pressure, by -1.71 mm Hg (95% CI -2.86, -0.56), compared to the control. Changes in lipid profile, blood glucose and body mass index were also assessed in the meta-analysis. A significant reduction was found in total cholesterol (-0.15 mmol/L [95% CI -0.27, -0.02]) and low-density lipoprotein cholesterol (-0.16 mmol/L [95% CI -0.22, -0.09]). Changes in other parameters did not reach statistical significance. Subgroup analysis suggested a greater reduction in both systolic and diastolic blood pressure in studies that included participants with a baseline mean systolic blood pressure of ≥ 130 mm Hg, and studies involving consuming green tea as an extract. CONCLUSION The present meta-analysis suggests that green tea and its catechins may improve blood pressure, and the effect may be greater in those with systolic blood pressure ≥ 130 mm Hg. The meta-analysis also suggests that green tea catechins may improve total and low-density lipoprotein cholesterol.
Collapse
Affiliation(s)
- Saman Khalesi
- Griffith Health Institute, Griffith University, Gold Coast, QLD, Australia,
| | | | | | | | | | | |
Collapse
|
31
|
Bøhn SK, Croft KD, Burrows S, Puddey IB, Mulder TPJ, Fuchs D, Woodman RJ, Hodgson JM. Effects of black tea on body composition and metabolic outcomes related to cardiovascular disease risk: a randomized controlled trial. Food Funct 2014; 5:1613-20. [DOI: 10.1039/c4fo00209a] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This randomised controlled double-blind 6 month parallel-designed trial indicates that ingestion of black tea over 3 months can improve body weight and body composition.
Collapse
Affiliation(s)
- Siv K. Bøhn
- Department of Nutrition
- Institute of Basic Medical Sciences
- Faculty of Medicine
- University of Oslo
- Norway
| | - Kevin D. Croft
- School of Medicine and Pharmacology
- University of Western Australia
- WAIMR Centre for Food and Genomic Medicine
- Perth, Australia
| | - Sally Burrows
- School of Medicine and Pharmacology
- University of Western Australia
- WAIMR Centre for Food and Genomic Medicine
- Perth, Australia
| | - Ian B. Puddey
- School of Medicine and Pharmacology
- University of Western Australia
- WAIMR Centre for Food and Genomic Medicine
- Perth, Australia
| | | | - Dagmar Fuchs
- Unilever Research and Development
- Vlaardingen, The Netherlands
| | | | - Jonathan M. Hodgson
- School of Medicine and Pharmacology
- University of Western Australia
- WAIMR Centre for Food and Genomic Medicine
- Perth, Australia
| |
Collapse
|
32
|
Blumberg JB. Introduction to the proceedings of the Fifth International Scientific Symposium on Tea and Human Health. Am J Clin Nutr 2013; 98:1607S-1610S. [PMID: 24172302 DOI: 10.3945/ajcn.113.060186] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Jeffrey B Blumberg
- Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University and the Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA
| |
Collapse
|
33
|
Hursel R, Westerterp-Plantenga MS. Catechin- and caffeine-rich teas for control of body weight in humans. Am J Clin Nutr 2013; 98:1682S-1693S. [PMID: 24172301 DOI: 10.3945/ajcn.113.058396] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Maintaining the level of daily energy expenditure during weight loss and weight maintenance is as important as maintaining satiety while decreasing energy intake. In this context, different catechin- and caffeine-rich teas (CCRTs), such as green, oolong, and white teas, as well as caffeine have been proposed as tools for maintaining or enhancing energy expenditure and for increasing fat oxidation. Tea polyphenols have been proposed to counteract the decrease in metabolic rate that is usually present during weight loss. Their effects may be of particular importance during weight maintenance after weight loss. Although the thermogenic effect of CCRT has the potential to produce significant effects on these metabolic targets as well as on fat absorption and energy intake, possibly via its impact on the gut microbiota and gene expression, a clinically meaningful outcome also depends on compliance by the subjects. Limitations to this approach require further examination, including moderating factors such as genetic predisposition, habitual caffeine intake, and catechin composition and dose. Nevertheless, CCRTs may be useful agents that could help in preventing a positive energy balance and obesity.
Collapse
Affiliation(s)
- Rick Hursel
- Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, Maastricht, Netherlands
| | | |
Collapse
|
34
|
Greenselect phytosome for borderline metabolic syndrome. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:869061. [PMID: 24348726 PMCID: PMC3848081 DOI: 10.1155/2013/869061] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 09/26/2013] [Accepted: 09/27/2013] [Indexed: 02/07/2023]
Abstract
The beneficial effects of Greenselect Phytosome, a proprietary lecithin formulation of a caffeine-free green tea catechin extract, were evaluated in a controlled registry study on 50 asymptomatic subjects borderline for metabolic syndrome factors and with increased plasma oxidative stress. After 24 weeks of intervention, improvement in weight, blood lipid profile, and blood pressure positioned 68% of subjects in the treatment arm out of the metabolic syndrome profile, while 80% of the subjects in the control group still remained in their initial borderline disease signature. Compared to the control (lifestyle and dietary changes alone), Greenselect Phytosome was especially effective for weight/waist changes. These results highlight the relevance of addressing multiple factors involved in the development of metabolic syndrome with a pleiotropic agent capable of improving the beneficial effects of lifestyle and dietary changes and foster the attainment of a globally improved health profile.
Collapse
|