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Association between coffee consumption with serum lipid profile in ELSA-Brasil study: a metabolomic approach. Eur J Nutr 2022; 61:4205-4214. [PMID: 35895137 DOI: 10.1007/s00394-022-02946-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 06/17/2022] [Indexed: 11/04/2022]
Abstract
PURPOSE This study evaluated the association between coffee consumption and serum lipid profile in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). METHODS This is a cross-sectional study on baseline data from participants of the cohort ELSA-Brasil. Only participants of São Paulo Research Center who underwent a nuclear magnetic resonance (NMR) spectroscopy examination of lipid profile were included (N = 4736). Coffee intake was categorized into four categories (cups/day, in reference cup size of 50 mL, which is the household measure adopted in Brazil): never/almost never, ≤ 1, 1-3, and > 3. Serum lipid profile [i.e., Total Cholesterol (TC), Total Triglycerides (TG), Very Low-Density Lipoprotein-cholesterol (VLDL-c), Low-Density Lipoprotein-cholesterol (LDL-c), High-Density Lipoprotein-cholesterol (HDL-c), Triglyceride-rich Lipoprotein Particles (TRLP) and subfractions particles] was analyzed. To estimate the effect of coffee consumption on serum lipid profile, multivariate Generalized Linear Models were performed. RESULTS Compared to participants who never or almost never drink coffee, individuals who consumed more than 3 cups/day showed an increase in concentrations of TC (β: 4.13; 95% CI 0.81, 7.45), TG (β: 9.53; 95% CI 1.65, 17.42), VLDL-c (β: 1.90; 95% CI 0.38, 3.42), TRLP (β: 8.42; 95% CI 1.24, 15.60), and Very Small-TRLP and Medium-TRLP subfractions (β: 7.36; 95% CI 0.21, 14.51; β: 2.53; 95% CI 0.89, 4.16, respectively), but not with HDL-c and LDL-c. Among individuals with low (≤ 1 cup/day) and moderate (1-3 cups/day) coffee consumption, no significant associations with lipids was observed. CONCLUSION High coffee consumption (more than 3 cups per day) was associated with an increase in serum lipids, namely TC, TG, VLDL-c, and TRL particles, highlighting the importance of a moderate consumption of this beverage.
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Chen L, Sun X, Zheng L. No causal effect of tea consumption on cardiovascular diseases: A two-sample Mendelian randomization study. Front Cardiovasc Med 2022; 9:870972. [PMID: 36158846 PMCID: PMC9491345 DOI: 10.3389/fcvm.2022.870972] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 08/15/2022] [Indexed: 11/16/2022] Open
Abstract
Background Numerous studies have been conducted to investigate the relationship between tea consumption and the risk of cardiovascular diseases (CVD); however, no conclusive results have been achieved. We conducted a Mendelian randomization (MR) study to elucidate the causal associations between tea consumption and several CVD outcomes, including coronary artery disease (CAD), myocardial infarction (MI), atrial fibrillation (AF), and heart failure (HF). Methods Independent single-nucleotide polymorphisms (SNPs) genome-wide significantly associated with tea consumption were used as instrumental variables (IVs). Summary statistics for CVD outcomes were obtained from the corresponding genetic consortia and the FinnGen consortium. The inverse-variance weighted (IVW) method was the primary analytical method, and MR estimates from different data sources were combined using fixed-effects meta-analysis. Supplementary MR analyses, including the weighted median, MR-Egger, and the MR pleiotropy residual sum and outlier methods, were conducted to evaluate the robustness of the results. Further MR analyses were repeated by including more genetic variants at a higher P-value threshold. Results We found that genetically predicted tea consumption was not causally associated with any CVD outcomes in the IVW method using data from large genetic consortia [CAD: odds ratio (OR) = 1.00, 95% confidence interval (CI), 0.91, 1.10, P = 0.997; MI: OR = 0.98, 95% CI, 0.90, 1.08, P = 0.751; AF: OR = 0.97, 95% CI, 0.92, 1.03, P = 0.350; HF: OR = 0.96, 95% CI, 0.88, 1.05, P = 0.401] or the FinnGen consortium (CAD: OR = 1.06, 95% CI, 0.96, 1.17, P = 0.225; MI: OR = 1.01, 95% CI, 0.89, 1.15, P = 0.882; AF: OR = 1.00, 95% CI, 0.88, 1.14, P = 0.994; HF: OR = 0.96, 95% CI, 0.88, 1.04, P = 0.362). The results were robust and consistent across meta-analysis, supplementary MR analyses, and analyses with more IVs included. Conclusion This MR study revealed no causal association between tea consumption and four CVD outcomes, suggesting that tea consumption may not be beneficial for the primary prevention of CVD.
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Affiliation(s)
- Lu Chen
- Department of Cardiology and Atrial Fibrillation Center, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xingang Sun
- Department of Cardiology and Atrial Fibrillation Center, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Liangrong Zheng
- Department of Cardiology and Atrial Fibrillation Center, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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Du Y, Lv Y, Zha W, Hong X, Luo Q. Effect of coffee consumption on dyslipidemia: A meta-analysis of randomized controlled trials. Nutr Metab Cardiovasc Dis 2020; 30:2159-2170. [PMID: 33239163 DOI: 10.1016/j.numecd.2020.08.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 07/27/2020] [Accepted: 08/14/2020] [Indexed: 11/24/2022]
Abstract
BACKGROUND AND AIM Dyslipidemia is a common metabolic disease worldwide and also an important predisposing factor for cardiovascular diseases (CVDs). Coffee is loved by people all over the world; however, the association between coffee consumption and blood lipids has yielded inconsistent results. So we carried this meta-analysis to explore the effects of coffee consumption on blood lipids. METHODS AND RESULTS Medline, PubMed, Web of science, Embase, and Cochrane Library databases were systematically searched until April 2020. Combined weighted mean differences (WMD) with their 95% confidence interval (CI) were calculated using random-effects models, and between-study heterogeneity was assessed by Cochran's Q test and I2 statistics. Subgroup analysis and meta-regression analysis were also conducted to explore the potential heterogeneity. A total of 12 RCT studies involving the association between coffee consumption and blood lipid levels were included in the meta-analysis. The pooled results showed that coffee consumption significantly increased total cholesterol (TC) (WMD: 0.21 mmol/L, 95% CI: 0.04; 0.39, P = 0.017), triglyceride (TG) (WMD: 0.12 mmol/L, 95% CI: 0.03; 0.20, P = 0.006) and low-density lipoprotein (LDL-C) (WMD: 0.14 mmol/L, 95% CI: 0.05; 0.24, P = 0.003) while had no significant effect on high-density lipoprotein (HDL-C) (WMD: -0.01 mmol/L, 95% CI: -0.06; 0.04, P = 0.707). Dose-response analysis results revealed significant positive nonlinear associations between coffee consumption and the increase in TC, LDL-C, and TG levels. CONCLUSIONS Evidence from this meta-analysis suggested that coffee consumption may be associated with an elevated risk for dyslipidemia and CVDs. So a reasonable habit of coffee consumption (<3 cups/d) is essential for the prevention of dyslipidemia.
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Affiliation(s)
- Yanbin Du
- MOE-LCSM, School of Mathematics and Statistics, Hunan Normal University, Changsha, Hunan Province, 410081, China.
| | - Yuan Lv
- Key Laboratory of Molecular Epidemiology, Medical College of Hunan Normal University, Changsha, Hunan Province, 410013, China.
| | - Wenting Zha
- Key Laboratory of Molecular Epidemiology, Medical College of Hunan Normal University, Changsha, Hunan Province, 410013, China.
| | - Xiuqin Hong
- Hunan Provincial People's Hospital, Scientific Research Department, Changsha, Hunan Province, 410005, China
| | - Qinghong Luo
- MOE-LCSM, School of Mathematics and Statistics, Hunan Normal University, Changsha, Hunan Province, 410081, China
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Abu-Taha M, Dagash R, Mohammad BA, Basheiti I, Abu-Samak MS. Combined Effect Of Coffee Consumption And Cigarette Smoking On Serum Levels Of Vitamin B12, Folic Acid, And Lipid Profile In Young Male: A Cross-Sectional Study. Int J Gen Med 2019; 12:421-432. [PMID: 31819593 PMCID: PMC6878925 DOI: 10.2147/ijgm.s213737] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 10/30/2019] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE To investigate the associations of coffee consumption and/or smoking on certain clinical outcomes including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), vitamin B12, and folic acid in a population of young healthy men. METHOD This cross-sectional study was conducted in Amman, Jordan, over 4 months. Participants were approached for study participation and asked to fill a questionnaire about their anthropometric information, habitual smoking, and coffee consumption during the last 3 months. Their fasting blood samples were taken to measure TC and LDL-C. RESULTS Healthy male participants (n=117) in the age range of 18 to 26 years were recruited. Mean serum TC was higher in heavy coffee consumers (C++) group (≥3 cups/day) with or without smoking (M= 179.9±34.59 mg/dL and 195.94±23.69 mg/dL) in comparison with moderate coffee consumers (C+) group (1-2 cups/day) (M= 158.1±24.82 mg/dL and 177.23±34.17 mg/dL), and the mean level was higher in subjects who were coffee consumers only than smokers who were coffee consumers. LDL-C levels were higher in participants who were coffee consumers (M= 103.06±34.82mg/dL and 118.06±19.31 mg/dL) than smokers who were coffee consumers (M= 88.6±22.40 mg/dL and 108.26±37.57 mg/dL). No significant difference was noted regarding HDL-C, vitamin B12, and folic acid. CONCLUSION Our findings showed that heavy coffee consumption was more associated with hyperlipidemia than cigarette smoking. Accordingly, we conclude that moderate coffee consumption may reduce the risk of cardiovascular diseases or their consequences in male.
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Affiliation(s)
- May Abu-Taha
- Department of Clinical Pharmacy and Therapeutics, Faculty of Pharmacy, Applied Science Private University, Amman, Jordan
| | - Rajaa Dagash
- Department of Clinical Pharmacy and Therapeutics, Faculty of Pharmacy, Applied Science Private University, Amman, Jordan
| | - Beisan A Mohammad
- PharmD Department, Fakeeh College for Medical Sciences, Jeddah, Kingdom of Saudi Arabia
| | - Iman Basheiti
- Department of Clinical Pharmacy and Therapeutics, Faculty of Pharmacy, Applied Science Private University, Amman, Jordan
| | - Mahmoud S Abu-Samak
- Department of Clinical Pharmacy and Therapeutics, Faculty of Pharmacy, Applied Science Private University, Amman, Jordan
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Acute and subacute (28 days) toxicity of green coffee oil enriched with diterpenes cafestol and kahweol in rats. Regul Toxicol Pharmacol 2019; 110:104517. [PMID: 31707131 DOI: 10.1016/j.yrtph.2019.104517] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 10/27/2019] [Accepted: 11/03/2019] [Indexed: 12/13/2022]
Abstract
Green coffee oil enriched with cafestol and kahweol was obtained by supercritical fluid extraction using carbon dioxide while its safety and possible effects from acute and subacute treatment were evaluated in rats. For acute toxicity study, single dose of green coffee oil (2000 mg/kg) was administered by gavage in female rats. For subacute study (28 days), 32 male rats received different doses of green coffee oil extract (25, 50, and 75 mg/kg/day). In the acute toxicity study, main findings of this treatment indicated no mortality, body weight decrease, no changes in hematological and biochemical parameters, and relative weight increase in heart and thymus, without histopathological alterations in all assessed organs. All these findings suggest that LD50 is higher than aforesaid dose. In the subacute toxicity, main findings showed body weight decrease mainly at the highest dose without food consumption change, serum glucose and tryglicerides levels decrease, and relative weight increase in liver. As evidenced in histopathological pictures, no changes were observed at all treated doses. Our study suggest that green coffee oil can be explored to clinically develop new hypocholesteromic and hypoglycemic agents. However, further studies evaluating long-term effects are needed in order to have sufficient safety evidence for its use in humans.
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Gaeini Z, Bahadoran Z, Mirmiran P, Azizi F. Tea, coffee, caffeine intake and the risk of cardio-metabolic outcomes: findings from a population with low coffee and high tea consumption. Nutr Metab (Lond) 2019; 16:28. [PMID: 31073321 PMCID: PMC6500051 DOI: 10.1186/s12986-019-0355-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 04/15/2019] [Indexed: 12/16/2022] Open
Abstract
Background This study aimed to assess the potential effects of long-term intake of caffeine and habitual consumption of coffee and tea on the occurrence of cardio-renal events among an Iranian population with low coffee and high tea consumption. Methods Adult participants of the Tehran Lipid and Glucose Study (2006-2008 to 2012-2014) who met the study inclusion criteria, were recruited. Habitual dietary intakes were assessed using a validated food frequency questionnaire. Demographics, anthropometrics, blood pressure, and biochemical variables were evaluated at baseline and during follow-up examinations. Multivariate Cox proportional hazard and logistic regression models adjusted for potential confounders were used to estimate the risk of cardiovascular disease (CVD), hypertension (HTN) and chronic kidney disease (CKD). Results During median 6 years of follow-up, the incidence rate of CVD outcomes, HTN, and CKD were 3.3%, 15.5%, and 17.9%, respectively. The risk of CVD was increased more than two-fold in the highest tertile of tea consumption (HR = 2.44, 95% confidence interval, CI = 1.40-4.27; P for trend = 0.001), and caffeine intakes (HR = 2.22, 95% CI = 1.23-4.01; P for trend = 0.005). A 42% lower incidence of CVD was observed in coffee drinkers, compared to non-drinkers (HR = 0.58, 95% CI = 0.36-0.93; P for trend = 0.023). No significant association was observed between tea, coffee or caffeine intakes and the risk of HTN or CKD. Conclusions Findings of our study support previous data regarding the protective effects of coffee on CVD. Contrary to the previous studies, we found that higher intakes of tea and caffeine, mainly originated from tea in our population, may increase risk of CVD events. It may be related to the type of tea and its preparation methods, additives or artificial colors in tea consumed in Iran, and sweets or sugar that mostly consumed accompanied by tea. Also, genetic variants of the liver enzymes may modify the association of dietary caffeine sources and incidence of CVD. Further prospective studies with incorporation of different population with different dietary habits and genetic backgrounds are needed to clarify the contradictions.
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Affiliation(s)
- Zahra Gaeini
- 1Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, P.O. Box 19395-4763, No. 24, Shahid-Erabi St., Yeman St., Velenjak, Tehran, Iran
| | - Zahra Bahadoran
- 1Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, P.O. Box 19395-4763, No. 24, Shahid-Erabi St., Yeman St., Velenjak, Tehran, Iran
| | - Parvin Mirmiran
- 2Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, P.O. Box 1981619573, No.47, Shahid Hafezi St. Farahzadi Blvd. Sharak-e- Ghods., Tehran, Iran
| | - Fereidoun Azizi
- 3Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Metabolic Syndrome: Preventive Effects of Dietary Flavonoids. STUDIES IN NATURAL PRODUCTS CHEMISTRY 2019. [DOI: 10.1016/b978-0-444-64181-6.00001-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Evidence for Grape, Wine and Tea Polyphenols as Modulators of Atherosclerosis and Ischemic Heart Disease in Humans. ACTA ACUST UNITED AC 2015. [DOI: 10.1300/j133v03n03_04] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Karabudak E, Türközü D, Köksal E. Association between coffee consumption and serum lipid profile. Exp Ther Med 2015; 9:1841-1846. [PMID: 26136902 DOI: 10.3892/etm.2015.2342] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 01/30/2015] [Indexed: 11/05/2022] Open
Abstract
The aim of the present study was to investigate the association between coffee consumption and serum lipid levels in a study population of 122 Turkish subjects (mean age, 41.4±12.69 years), including 48 males and 74 females. A questionnaire was compiled to determine baseline characteristics, and food and coffee consumption. Subjects were divided into three groups, which included non-drinkers, Turkish coffee and instant coffee drinkers, and anthropometric measurements were acquired, including weight, height and body mass index. Serum lipid levels were analyzed, including the total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and very low-density lipoprotein cholesterol (VLDL-C) levels. Of the population studied, 76.2% had consumed at least one cup of coffee per week over the previous year. Daily consumption values were 62.3±40.60 ml (0.7±0.50 cup) for Turkish coffee and 116.3±121.96 ml (0.7±0.81 cup) for instant coffee. No statistically significant differences were observed in the serum levels of TC, TG, LDL-C, HDL-C or VLDL-C among the three groups. In addition, no statistically significant differences were observed in the serum lipid levels when comparing individuals who consumed coffee with sugar/cream or who smoked and those who did not (P>0.05). Therefore, the present observations indicated no significant association between the consumption of Turkish or instant coffee and serum lipid levels.
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Affiliation(s)
- Efsun Karabudak
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Gazi University, Ankara 06500, Turkey
| | - Duygu Türközü
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Gazi University, Ankara 06500, Turkey
| | - Eda Köksal
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Gazi University, Ankara 06500, Turkey
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Tuso P, Stoll SR, Li WW. A plant-based diet, atherogenesis, and coronary artery disease prevention. Perm J 2014; 19:62-7. [PMID: 25431999 DOI: 10.7812/tpp/14-036] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
A plant-based diet is increasingly becoming recognized as a healthier alternative to a diet laden with meat. Atherosclerosis associated with high dietary intake of meat, fat, and carbohydrates remains the leading cause of mortality in the US. This condition results from progressive damage to the endothelial cells lining the vascular system, including the heart, leading to endothelial dysfunction. In addition to genetic factors associated with endothelial dysfunction, many dietary and other lifestyle factors, such as tobacco use, high meat and fat intake, and oxidative stress, are implicated in atherogenesis. Polyphenols derived from dietary plant intake have protective effects on vascular endothelial cells, possibly as antioxidants that prevent the oxidation of low-density lipoprotein. Recently, metabolites of L-carnitine, such as trimethylamine-N-oxide, that result from ingestion of red meat have been identified as a potential predictive marker of coronary artery disease (CAD). Metabolism of L-carnitine by the intestinal microbiome is associated with atherosclerosis in omnivores but not in vegetarians, supporting CAD benefits of a plant-based diet. Trimethylamine-N-oxide may cause atherosclerosis via macrophage activation. We suggest that a shift toward a plant-based diet may confer protective effects against atherosclerotic CAD by increasing endothelial protective factors in the circulation while reducing factors that are injurious to endothelial cells. The relative ratio of protective factors to injurious endothelial exposure may be a novel approach to assessing an objective dietary benefit from a plant-based diet. This review provides a mechanistic perspective of the evidence for protection by a plant-based diet against atherosclerotic CAD.
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Affiliation(s)
- Phillip Tuso
- Physician Leader for Total Health in Southern California.
| | | | - William W Li
- President and Medical Director of the Angiogenesis Foundation of the Institute for Advance Studies in Cambridge, MA.
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CD39/NTPDase-1 expression and activity in human umbilical vein endothelial cells are differentially regulated by leaf extracts from Rubus caesius and Rubus idaeus. Cell Mol Biol Lett 2014; 19:361-80. [PMID: 25034034 PMCID: PMC6275654 DOI: 10.2478/s11658-014-0202-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 07/08/2014] [Indexed: 12/21/2022] Open
Abstract
Many experimental studies have demonstrated the favorable biological activities of plants belonging to the genus Rubus, but little is known of the role of Rubus leaf extracts in the modulation of the surface membrane expression and activity of endothelial apyrase. The aim of this study was to assess the influence of 1–15 μg/ml Rubus extracts on CD39 expression and enzymatic activity, and on the activation (ICAM-1 expression) and viability of human umbilical vein endothelial cells (HUVEC). The polyphenolic contents and antioxidative capacities of extracts from dewberry (R. caesius L.) and raspberry (R. idaeus L.) leaves were also investigated. The techniques applied were flow cytometry (endothelial surface membrane expression of ICAM-1 and CD39), malachite green assay (CD39 activity), HPLC-DAD (quantitative analysis of polyphenolic extract), ABTS, DPPH and FRAP spectrometric assays (antioxidant capacity), and the MTT test (cell viability). Significantly increased CD39 expressions and significantly decreased ATPDase activities were found in the cells treated with 15 μg/ml of either extract compared to the results for the controls. Neither of the extracts affected cell proliferation, but both significantly augmented endothelial cell ICAM-1 expression. The overall antioxidant capacities of the examined extracts remained relatively high and corresponded well to the determined total polyphenol contents. Overall, the results indicate that under in vitro conditions dewberry and raspberry leaf extracts have unfavorable impact on endothelial cells.
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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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Pyshchyta G, Mukamal KJ, Ahnve S, Hallqvist J, Gémes K, Ahlbom A, Janszky I. Tea consumption, incidence and long-term prognosis of a first acute myocardial infarction – The SHEEP study. Clin Nutr 2012; 31:267-72. [DOI: 10.1016/j.clnu.2011.10.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 10/06/2011] [Accepted: 10/21/2011] [Indexed: 10/15/2022]
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Ruxton CHS, Mason P. Is black tea consumption associated with a lower risk of cardiovascular disease and type 2 diabetes? NUTR BULL 2011. [DOI: 10.1111/j.1467-3010.2011.01937.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Barringer TA, Hatcher L, Sasser HC. Potential benefits on impairment of endothelial function after a high-fat meal of 4 weeks of flavonoid supplementation. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2011; 2011:796958. [PMID: 18955351 PMCID: PMC3137609 DOI: 10.1093/ecam/nen048] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Accepted: 05/30/2008] [Indexed: 11/14/2022]
Abstract
Studies with foods high in flavonoids have demonstrated improvement in endothelial function. We investigated whether 4 weeks of flavonoid supplementation would prevent an adverse impact on endothelial function of a high-fat meal. Endothelial function was measured by reactive hyperemia peripheral arterial tonometry (RH-PAT). The RH-PAT index was measured both before and 3 h after a high-fat meal, in 23 healthy volunteers. Subjects were randomized in a double-blind, cross-over design to 4 weeks of daily supplementation with OPC-3, or a matching placebo. RH-PAT index before and after the high-fat meal was measured at the beginning and end of each 4-week treatment phase. The high-fat meal caused a decline in endothelial function at baseline in the placebo (-10.71%, P = .006) and flavonoid [-9.97% (P = .077)] groups, and there was no difference in decline between arms (P = .906). The high-fat meal produced a decline after 4 weeks of placebo [-12.37% (P = .005)], but no decline after 4 weeks of flavonoid supplement [-3.16% (P = .663)], and the difference between the two responses was highly significant (P < .0001). Within-group comparisons revealed no difference in endothelial function decline in the placebo arm between baseline and 4 weeks [-10.71% versus -12.37% (P = .758)]. In the flavonoid supplement arm, the difference in endothelial function decline between baseline and 4 weeks was -9.97% versus -3.16%, but did not reach statistical significance (P = .451). These results suggest that the flavonoid supplement used in this study mitigates the impairment of endothelial function caused by a high-fat meal. Whether certain subpopulations derive greater or lesser benefit remains unclear.
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Affiliation(s)
- T A Barringer
- Center for Cardiovascular Health (TAB, LH) and Dickson Institute for Health Studies (HCS), Carolinas Healthcare System, P.O. Box 32861, Charlotte, NC 28232, USA
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Deka A, Vita JA. Tea and cardiovascular disease. Pharmacol Res 2011; 64:136-45. [PMID: 21477653 DOI: 10.1016/j.phrs.2011.03.009] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2010] [Accepted: 03/22/2011] [Indexed: 12/31/2022]
Abstract
There is increasing evidence for a protective effect of tea consumption against cardiovascular disease. This review summarizes the available epidemiological data providing evidence for and against such an effect. We also review observational and intervention studies that investigated an effect of tea and tea extracts on cardiovascular risk factors, including blood pressure, serum lipids, diabetes mellitus, and obesity. Finally, we review potential mechanisms of benefit, including anti-inflammatory, anti-oxidant, and anti-proliferative effects, as well as favorable effects on endothelial function. Overall, the observational data suggest a benefit, but results are mixed and likely confounded by lifestyle and background dietary factors. The weight of evidence indicates favorable effects on risk factors and a number of plausible mechanisms have been elucidated in experimental and translational human studies. Despite the growing body evidence, it remains uncertain whether tea consumption should be recommended to the general population or to patients as a strategy to reduce cardiovascular risk.
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Affiliation(s)
- Apranta Deka
- Evans Department of Medicine and the Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, United States
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Shukla SK, Gupta S, Ojha SK, Sharma SB. Cardiovascular friendly natural products: a promising approach in the management of CVD. Nat Prod Res 2010; 24:873-98. [PMID: 20461632 DOI: 10.1080/14786410903417378] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Natural products play an important role as nutritional supplements and provide potential health benefits in cardiovascular diseases (CVD). Compiling data from experimental, epidemiological and clinical studies indicates that dietary nutrients have profound cardioprotective effects in the primary as well as secondary prevention of coronary heart disease, hence they are considered as cardiovascular friendly natural products. The mechanism of cardioprotection produced by dietary nutritional supplements such as flavonoids (citrus fruits, pulses, red wine, tea and cocoa), olive oil, omega-3 (omega-3) fatty acids (fish oil and fish-based products), lycopene (tomato and tomato-based products), resveratrol (grapes and red wine), coffee, and soy in the prevention and treatment of cardiovascular disorders have been discussed in the present review, with the emphasis of epidemiological and clinical studies. Based on the intriguing results of various studies, prophylactic and therapeutic potential of cardiovascular friendly natural products have been suggested. The supplementation of cardiovascular friendly natural products needs to be considered in all populations who have high prevalence of CVD.
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Affiliation(s)
- Santosh K Shukla
- Department of Biochemistry, University College of Medical Sciences, University of Delhi, Delhi, India
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Grassi D, Aggio A, Onori L, Croce G, Tiberti S, Ferri C, Ferri L, Desideri G. Tea, flavonoids, and nitric oxide-mediated vascular reactivity. J Nutr 2008; 138:1554S-1560S. [PMID: 18641206 DOI: 10.1093/jn/138.8.1554s] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Epidemiological evidence supports the concept that diets rich in fruits and vegetables promote health and attenuate or delay the onset of cardiovascular disease (CVD). Although a variety of factors contribute to the beneficial effects of plant foods, much attention has been addressed to plant polyphenols. In this regard, in the daily Western diet, both black and green teas contribute to a relevant proportion of total phenol intake. The more abundant class of flavonoids that is present in teas is represented by flavanols, i.e., catechin, epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate. Studies using animal models of atherosclerosis indicate that dietary flavonoid consumption delays atherosclerotic plaque development. Accordingly, an inverse association between tea intake and CVD has been demonstrated. Further, flavonoids can reduce endothelial dysfunction, i.e., the key step in the development of atherosclerosis. Concordantly, human data suggest that tea may reduce blood pressure levels. Despite this, although they often show that tea may have cardiovascular protective effects, results from epidemiological studies exploring the association between tea and health are controversial. Conflicting results may be caused by disparate study designs and flavonoid contents in different kinds of tea. Thus, because tea is a popular beverage worldwide, and several studies have shown that it is protective against CVD, further studies are needed to determine the role of tea in primary and secondary cardiovascular prevention.
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Affiliation(s)
- Davide Grassi
- Department of Internal Medicine and Public Health, University of L'Aquila, 67100 L'Aquila, Italy
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Hooper L, Kroon PA, Rimm EB, Cohn JS, Harvey I, Le Cornu KA, Ryder JJ, Hall WL, Cassidy A. Flavonoids, flavonoid-rich foods, and cardiovascular risk: a meta-analysis of randomized controlled trials. Am J Clin Nutr 2008; 88:38-50. [PMID: 18614722 DOI: 10.1093/ajcn/88.1.38] [Citation(s) in RCA: 703] [Impact Index Per Article: 43.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND The beneficial effects of flavonoid consumption on cardiovascular risk are supported by mechanistic and epidemiologic evidence. OBJECTIVE We aimed to systematically review the effectiveness of different flavonoid subclasses and flavonoid-rich food sources on cardiovascular disease (CVD) and risk factors--ie, lipoproteins, blood pressure, and flow-mediated dilatation (FMD). DESIGN Methods included a structured search strategy on MEDLINE, EMBASE, and Cochrane databases; formal inclusion or exclusion, data extraction, and validity assessment; and meta-analysis. RESULTS One hundred thirty-three trials were included. No randomized controlled trial studied effects on CVD morbidity or mortality. Significant heterogeneity confirmed differential effects between flavonoid subclasses and foods. Chocolate increased FMD after acute (3.99%; 95% CI: 2.86, 5.12; 6 studies) and chronic (1.45%; 0.62, 2.28; 2 studies) intake and reduced systolic (-5.88 mm Hg; -9.55, -2.21; 5 studies) and diastolic (-3.30 mm Hg; -5.77, -0.83; 4 studies) blood pressure. Soy protein isolate (but not other soy products or components) significantly reduced diastolic blood pressure (-1.99 mm Hg; -2.86, -1.12; 9 studies) and LDL cholesterol (-0.19 mmol/L; -0.24, -0.14; 39 studies). Acute black tea consumption increased systolic (5.69 mm Hg; 1.52, 9.86; 4 studies) and diastolic (2.56 mm Hg; 1.03, 4.10; 4 studies) blood pressure. Green tea reduced LDL (-0.23 mmol/L; -0.34, -0.12; 4 studies). For many of the other flavonoids, there was insufficient evidence to draw conclusions about efficacy. CONCLUSIONS To date, the effects of flavonoids from soy and cocoa have been the main focus of attention. Future studies should focus on other commonly consumed subclasses (eg, anthocyanins and flavanones), examine dose-response effects, and be of long enough duration to allow assessment of clinically relevant endpoints.
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Affiliation(s)
- Lee Hooper
- School of Medicine, Health Policy and Practice, University of East Anglia, Norwich, United Kingdom.
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Debette S, Courbon D, Leone N, Gariépy J, Tzourio C, Dartigues JF, Barberger-Gateau P, Ritchie K, Alpérovitch A, Amouyel P, Ducimetière P, Zureik M. Tea Consumption Is Inversely Associated With Carotid Plaques in Women. Arterioscler Thromb Vasc Biol 2008; 28:353-9. [DOI: 10.1161/atvbaha.107.151928] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Stéphanie Debette
- From Inserm, U744 (S.D., D.C., P.A., M.Z.), Lille; Department of Neurology (EA2691) (S.D.), University Hospital of Lille; Inserm, U700 (D.C., N.L., M.Z.), Paris; Inserm, U708 (C.T., A.A.), Paris; Inserm, U593 (J.F.D., P.B.G.), Bordeaux; Inserm, E0361 (K.R.), Montpellier; Inserm, U780 (P.D.), Paris; Centre de Médecine Préventive Cardiovasculaire (J.G.), Broussais Hospital, Paris, France
| | - Dominique Courbon
- From Inserm, U744 (S.D., D.C., P.A., M.Z.), Lille; Department of Neurology (EA2691) (S.D.), University Hospital of Lille; Inserm, U700 (D.C., N.L., M.Z.), Paris; Inserm, U708 (C.T., A.A.), Paris; Inserm, U593 (J.F.D., P.B.G.), Bordeaux; Inserm, E0361 (K.R.), Montpellier; Inserm, U780 (P.D.), Paris; Centre de Médecine Préventive Cardiovasculaire (J.G.), Broussais Hospital, Paris, France
| | - Nathalie Leone
- From Inserm, U744 (S.D., D.C., P.A., M.Z.), Lille; Department of Neurology (EA2691) (S.D.), University Hospital of Lille; Inserm, U700 (D.C., N.L., M.Z.), Paris; Inserm, U708 (C.T., A.A.), Paris; Inserm, U593 (J.F.D., P.B.G.), Bordeaux; Inserm, E0361 (K.R.), Montpellier; Inserm, U780 (P.D.), Paris; Centre de Médecine Préventive Cardiovasculaire (J.G.), Broussais Hospital, Paris, France
| | - Jérôme Gariépy
- From Inserm, U744 (S.D., D.C., P.A., M.Z.), Lille; Department of Neurology (EA2691) (S.D.), University Hospital of Lille; Inserm, U700 (D.C., N.L., M.Z.), Paris; Inserm, U708 (C.T., A.A.), Paris; Inserm, U593 (J.F.D., P.B.G.), Bordeaux; Inserm, E0361 (K.R.), Montpellier; Inserm, U780 (P.D.), Paris; Centre de Médecine Préventive Cardiovasculaire (J.G.), Broussais Hospital, Paris, France
| | - Christophe Tzourio
- From Inserm, U744 (S.D., D.C., P.A., M.Z.), Lille; Department of Neurology (EA2691) (S.D.), University Hospital of Lille; Inserm, U700 (D.C., N.L., M.Z.), Paris; Inserm, U708 (C.T., A.A.), Paris; Inserm, U593 (J.F.D., P.B.G.), Bordeaux; Inserm, E0361 (K.R.), Montpellier; Inserm, U780 (P.D.), Paris; Centre de Médecine Préventive Cardiovasculaire (J.G.), Broussais Hospital, Paris, France
| | - Jean-François Dartigues
- From Inserm, U744 (S.D., D.C., P.A., M.Z.), Lille; Department of Neurology (EA2691) (S.D.), University Hospital of Lille; Inserm, U700 (D.C., N.L., M.Z.), Paris; Inserm, U708 (C.T., A.A.), Paris; Inserm, U593 (J.F.D., P.B.G.), Bordeaux; Inserm, E0361 (K.R.), Montpellier; Inserm, U780 (P.D.), Paris; Centre de Médecine Préventive Cardiovasculaire (J.G.), Broussais Hospital, Paris, France
| | - Pascale Barberger-Gateau
- From Inserm, U744 (S.D., D.C., P.A., M.Z.), Lille; Department of Neurology (EA2691) (S.D.), University Hospital of Lille; Inserm, U700 (D.C., N.L., M.Z.), Paris; Inserm, U708 (C.T., A.A.), Paris; Inserm, U593 (J.F.D., P.B.G.), Bordeaux; Inserm, E0361 (K.R.), Montpellier; Inserm, U780 (P.D.), Paris; Centre de Médecine Préventive Cardiovasculaire (J.G.), Broussais Hospital, Paris, France
| | - Karen Ritchie
- From Inserm, U744 (S.D., D.C., P.A., M.Z.), Lille; Department of Neurology (EA2691) (S.D.), University Hospital of Lille; Inserm, U700 (D.C., N.L., M.Z.), Paris; Inserm, U708 (C.T., A.A.), Paris; Inserm, U593 (J.F.D., P.B.G.), Bordeaux; Inserm, E0361 (K.R.), Montpellier; Inserm, U780 (P.D.), Paris; Centre de Médecine Préventive Cardiovasculaire (J.G.), Broussais Hospital, Paris, France
| | - Annick Alpérovitch
- From Inserm, U744 (S.D., D.C., P.A., M.Z.), Lille; Department of Neurology (EA2691) (S.D.), University Hospital of Lille; Inserm, U700 (D.C., N.L., M.Z.), Paris; Inserm, U708 (C.T., A.A.), Paris; Inserm, U593 (J.F.D., P.B.G.), Bordeaux; Inserm, E0361 (K.R.), Montpellier; Inserm, U780 (P.D.), Paris; Centre de Médecine Préventive Cardiovasculaire (J.G.), Broussais Hospital, Paris, France
| | - Philippe Amouyel
- From Inserm, U744 (S.D., D.C., P.A., M.Z.), Lille; Department of Neurology (EA2691) (S.D.), University Hospital of Lille; Inserm, U700 (D.C., N.L., M.Z.), Paris; Inserm, U708 (C.T., A.A.), Paris; Inserm, U593 (J.F.D., P.B.G.), Bordeaux; Inserm, E0361 (K.R.), Montpellier; Inserm, U780 (P.D.), Paris; Centre de Médecine Préventive Cardiovasculaire (J.G.), Broussais Hospital, Paris, France
| | - Pierre Ducimetière
- From Inserm, U744 (S.D., D.C., P.A., M.Z.), Lille; Department of Neurology (EA2691) (S.D.), University Hospital of Lille; Inserm, U700 (D.C., N.L., M.Z.), Paris; Inserm, U708 (C.T., A.A.), Paris; Inserm, U593 (J.F.D., P.B.G.), Bordeaux; Inserm, E0361 (K.R.), Montpellier; Inserm, U780 (P.D.), Paris; Centre de Médecine Préventive Cardiovasculaire (J.G.), Broussais Hospital, Paris, France
| | - Mahmoud Zureik
- From Inserm, U744 (S.D., D.C., P.A., M.Z.), Lille; Department of Neurology (EA2691) (S.D.), University Hospital of Lille; Inserm, U700 (D.C., N.L., M.Z.), Paris; Inserm, U708 (C.T., A.A.), Paris; Inserm, U593 (J.F.D., P.B.G.), Bordeaux; Inserm, E0361 (K.R.), Montpellier; Inserm, U780 (P.D.), Paris; Centre de Médecine Préventive Cardiovasculaire (J.G.), Broussais Hospital, Paris, France
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Abstract
Abnormalities of the vascular endothelium contribute to all stages of atherosclerosis from lesion development to clinical cardiovascular disease events. Recognized risk factors, including diabetes mellitus, hypertension, dyslipidemia, cigarette smoking, and sedentary lifestyle are associated with endothelial dysfunction. A variety of pharmacological and behavioral interventions have been shown to reverse endothelial dysfunction in patients with cardiovascular disease. A large number of epidemiological studies suggest that dietary factors, including increased intake of flavonoid-containing foods and beverages, reduce cardiovascular risk, and recent studies have shown that such beverages have favorable effects on endothelial function. These studies have engendered interest in the development of dietary supplements or drugs that would allow for more convenient and higher dose administration of flavonoids and might prove useful for prevention or treatment of cardiovascular disease. In this paper, we will review the contribution of endothelial dysfunction to the pathogenesis and clinical expression of atherosclerosis and recent data linking flavonoid and EGCG consumption to improved endothelial function and reduced cardiovascular risk.
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Affiliation(s)
- Sherene M Shenouda
- Boston University School of Medicine, 88 East Newton Street, C-818, Boston, MA 02118, USA
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22
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Kyle JAM, Morrice PC, McNeill G, Duthie GG. Effects of infusion time and addition of milk on content and absorption of polyphenols from black tea. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2007; 55:4889-94. [PMID: 17489604 DOI: 10.1021/jf070351y] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Epidemiological studies assessing the health benefits of drinking black tea are equivocal. Such disparity may reflect an inability of semiquantitative assessment to consider how infusion time and addition of milk affect the bioavailability of potentially beneficial antioxidant polyphenols. Six brands of tea demonstrated similar increases in antioxidant capacity and total phenolic and catechin contents with increasing infusion time. These results were unaffected by the addition of milk. Consumption of black tea (400 mL) was associated with significant increases in plasma antioxidant capacity (10%) and concentrations of total phenols (20%), catechins (32%), and the flavonols quercetin (39%) and kaempferol (45%) (all p < 0.01) within 80 min. This was unaffected by adding milk. Infusion time may therefore be a more important determinant in the absorption of polyphenols from black tea. Observational studies assessing the health benefits of tea consumption require recording of brewing methods as well as frequency of consumption.
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Affiliation(s)
- Janet A M Kyle
- Rowett Research Institute, Aberdeen AB21 9SB, Scotland, U.K.
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23
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Sofi F, Conti AA, Gori AM, Eliana Luisi ML, Casini A, Abbate R, Gensini GF. Coffee consumption and risk of coronary heart disease: a meta-analysis. Nutr Metab Cardiovasc Dis 2007; 17:209-223. [PMID: 17156982 DOI: 10.1016/j.numecd.2006.07.013] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2006] [Revised: 07/14/2006] [Accepted: 07/22/2006] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND AIMS During the past three decades the relationship between habitual coffee drinking and coronary heart disease (CHD) has been assessed in numerous studies, with conflicting results. The aim of this study was to systematically examine the data published on the association between habitual coffee consumption and risk of CHD. METHODS AND RESULTS Thirteen case-control and 10 cohort studies were included. Case-control studies incorporated 9487 cases of CHD and 27,747 controls, and cohort studies included a total of 403,631 participants that were followed for between 3 and 44 years. The summary of odds ratios (OR) for the case-control studies showed statistically significant associations between coffee consumption and CHD for the highest intake group (>4 cups/day), OR 1.83 (95% CI 1.49-2.24; P<0.0001), and for the second highest category (3-4 cups/day), OR 1.33 (95% CI 1.04-1.71; P<0.0001), while no significant association emerged for low daily coffee intake (< or =2 cups/day), OR 1.03 (95% CI 0.87-1.21; P=0.45). The analysis of long-term follow-up cohort studies did not show any association between the consumption of coffee and CHD, with a relative risk (RR) of 1.16 (95% CI 0.95-1.41; P=0.14) for the highest category, and 1.05 (95% CI 0.90-1.22; P=0.57) and 1.04 (95% CI 0.90-1.19; P=0.60) for the second and third highest categories, respectively. These results did not differ substantially when controlling for region of origin, fatal and non-fatal events, year of publication, and number of years of follow-up. CONCLUSIONS Despite a significant association between high consumption of coffee and CHD reported among case-control studies, no significant association between daily coffee consumption and CHD emerged from long-term follow-up prospective cohort studies.
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Affiliation(s)
- Francesco Sofi
- Department of Medical and Surgical Critical Care and Center for the Study at Molecular and Clinical Level of Chronic, Degenerative and Neoplastic Diseases to Develop Novel Therapies, University of Florence, Florence, Italy.
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24
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Erdman JW, Balentine D, Arab L, Beecher G, Dwyer JT, Folts J, Harnly J, Hollman P, Keen CL, Mazza G, Messina M, Scalbert A, Vita J, Williamson G, Burrowes J. Flavonoids and heart health: proceedings of the ILSI North America Flavonoids Workshop, May 31-June 1, 2005, Washington, DC. J Nutr 2007; 137:718S-737S. [PMID: 17311968 DOI: 10.1093/jn/137.3.718s] [Citation(s) in RCA: 233] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
This article provides an overview of current research on flavonoids as presented during a workshop entitled, "Flavonoids and Heart Health," held by the ILSI North America Project Committee on Flavonoids in Washington, DC, May 31 and June 1, 2005. Because a thorough knowledge and understanding about the science of flavonoids and their effects on health will aid in establishing dietary recommendations for bioactive components such as flavonoids, a systematic review of the science of select flavonoid classes (i.e., flavonols, flavones, flavanones, isoflavones, flavan-3-ols, anthocyanins, and proanthocyanidins) was presented. The objectives of the workshop were to 1) present and discuss current research on flavonoid intake and the relation between flavonoids and heart health; 2) develop information that could lead to expert consensus on the state-of-the-science of dietary intake of flavonoids on heart health; and 3) summarize and prioritize the research needed to establish the relations between specific flavonoids and heart health. Presentations included the basics of the biology of flavonoids, including the types and distribution in foods, analytical methodologies used to determine the amounts in foods, the bioavailability, the consumption patterns and potential biomarkers of intake, risk assessment and safety evaluation, structure/function claims, and the proposed mechanism(s) of the relation between certain flavonoids and heart health endpoints. Data presented support the concept that certain flavonoids in the diet can be associated with significant health benefits, including heart health. Research gaps were identified to help advance the science.
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Affiliation(s)
- John W Erdman
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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25
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Widlansky ME, Duffy SJ, Hamburg NM, Gokce N, Warden BA, Wiseman S, Keaney JF, Frei B, Vita JA. Effects of black tea consumption on plasma catechins and markers of oxidative stress and inflammation in patients with coronary artery disease. Free Radic Biol Med 2005; 38:499-506. [PMID: 15649652 DOI: 10.1016/j.freeradbiomed.2004.11.013] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2004] [Revised: 11/04/2004] [Accepted: 11/05/2004] [Indexed: 12/23/2022]
Abstract
We previously demonstrated that black tea consumption reverses endothelial dysfunction in patients with coronary artery disease. To investigate potential mechanisms of this effect, we examined plasma catechins and systemic markers of oxidation, inflammation, and antioxidant protection from 66 subjects enrolled in that study. We collected samples at baseline, 2 h after 450 ml of black tea (acute), after 4 weeks of 900 ml of black tea per day (chronic), and after acute and chronic consumption of water. Total catechins increased 33% after acute tea (P < 0.05) and 29% after chronic tea (P < 0.05). Of individual catechins, plasma epicatechin gallate (ECG) concentration significantly increased with acute tea consumption, and plasma epicatechin (EC) increased with chronic tea consumption. Tea consumption did not improve plasma antioxidant capacity and did not reduce urinary 8-hydroxy-2'-deoxyguanosine, or urinary 8-isoprostane levels. Changes in catechin levels did not correlate with changes in endothelial function, plasma markers of oxidative stress, or C-reactive protein. In contrast, endothelial function at baseline correlated with dietary flavonoid intake (beta = 0.32, P = 0.02) and with baseline plasma EC concentration after adjusting for confounding variables (beta = 0.39, P = 0.03). These findings suggest that the benefits of black tea consumption on endothelial function may not be attributable to tea catechins or a systemic antioxidant or anti-inflammatory effect. Chronic dietary flavonoid status appears to relate to endothelial function, possibly suggesting that other flavonoids or polyphenolic components of tea favorably influence vascular health and risk for cardiovascular disease.
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Affiliation(s)
- Michael E Widlansky
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
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26
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Vita JA. Polyphenols and cardiovascular disease: effects on endothelial and platelet function. Am J Clin Nutr 2005; 81:292S-297S. [PMID: 15640493 DOI: 10.1093/ajcn/81.1.292s] [Citation(s) in RCA: 331] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Epidemiologic studies suggest that higher polyphenol intake from fruits and vegetables is associated with decreased risk for cardiovascular disease. The mechanisms explaining this observation remain unclear. This review summarizes data suggesting that flavonoids improve endothelial function and inhibit platelet aggregation in humans. The vascular endothelium is a critical regulator of vascular homeostasis, and endothelial dysfunction contributes to the pathogenesis and clinical expression of coronary artery disease. Platelet aggregation is a central mechanism in the pathogenesis of acute coronary syndromes, including myocardial infarction and unstable angina. For these reasons, the observed effects of flavonoids on endothelial and platelet function might explain, in part, the observed beneficial effects of flavonoids on cardiovascular disease risk.
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Affiliation(s)
- Joseph A Vita
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA.
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27
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Black tea consumption and serum lipid profiles in Saudi women: a cross-sectional study in Saudi Arabia. Nutr Res 2003. [DOI: 10.1016/s0271-5317(03)00176-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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28
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Abstract
Epidemiological studies suggest that tea consumption is associated with reduced cardiovascular disease risk, but the mechanisms for these observations have remained uncertain. In recent years, it has become apparent that the endothelium plays a central role in the regulation of vascular homeostasis and that endothelial dysfunction contributes to the pathogenesis and clinical expression of cardiovascular disease. This article reviews the evidence that human tea consumption has a beneficial effect on the vascular endothelium and the clinical implications of these findings.
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Affiliation(s)
- Joseph A Vita
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA.
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Sesso HD, Paffenbarger RS, Oguma Y, Lee IM. Lack of association between tea and cardiovascular disease in college alumni. Int J Epidemiol 2003; 32:527-33. [PMID: 12913023 DOI: 10.1093/ije/dyg103] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Epidemiological studies suggest that tea intake, a major dietary source of flavonoids, may be associated with a decreased risk of cardiovascular disease (CVD). METHODS We prospectively followed 17 228 subjects (mean age, 59.5 years) initially free of CVD and cancer from the College Alumni Health Study. Participants provided baseline self-reports of tea consumption (cups/day) and coronary risk factors. During a median follow-up of 15 years, there were 3372, 2615, and 757 cases of CVD, coronary heart disease (CHD), and stroke, respectively, ascertained from either self-reports or death certificates. RESULTS Overall, the median level of tea consumption was 1 cup/day. Compared with participants consuming no tea, the multivariate relative risks (RR) of CVD for those drinking <1, 1, 2, 3, and >/=4 cups/day were 0.99, 0.96, 0.95, 0.91, and 0.95, respectively (P, trend = 0.19). The multivariate RR were 0.97, 0.98, 0.93, 0.85, and 0.98 for CHD (P, trend = 0.25), and 1.05, 0.89, 1.00, 1.09, and 0.83 for stroke (P, trend = 0.53). There was no evidence of effect modification. Changes in tea intake were assessed in a subgroup of 7730 men, with those continuing to drink tea having a non-significant 33% reduction in the risk of stroke. CONCLUSIONS Tea intake, likely consumed as black tea, was not strongly associated with a reduced risk of CVD in this population of US college alumni.
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Affiliation(s)
- Howard D Sesso
- Department of Epidemiology, Harvard School of Public Health, Boston, MA USA
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Mennen LI, Malvy D, Galan P, Preziosi P, Bertrais S, Bruckert E, Maurel M, Franchisseur C, Hercberg S. Tea consumption and cardiovascular risk in the SU.VI.MAX Study: Are life-style factors important? Nutr Res 2003. [DOI: 10.1016/s0271-5317(03)00073-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Cameron J, Grassi G. Effects of caffeine on arterial function and haemodynamics: implications for cardiovascular risk. J Hypertens 2003; 21:491-3. [PMID: 12640238 DOI: 10.1097/00004872-200303000-00010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Hakim IA, Alsaif MA, Alduwaihy M, Al-Rubeaan K, Al-Nuaim AR, Al-Attas OS. Tea consumption and the prevalence of coronary heart disease in Saudi adults: results from a Saudi national study. Prev Med 2003; 36:64-70. [PMID: 12473426 DOI: 10.1006/pmed.2002.1130] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND The aim of the study was to determine whether there was a relationship between tea consumption and the prevalence of coronary heart disease (CHD) in Saudi Arabia. METHODS The relationship between tea consumption and the prevalence of CHD was investigated using multiple logistic regression analysis in the Saudi Coronary Artery Disease Study. A total of 3,430 men and women aged 30-70 years was studied. RESULTS Of the 3,430 subjects who were assigned a category, 6.3% were classified as having indications of CHD. Those who did drink more than 6 cups of tea (>480 mL) per day had a significantly lower prevalence of CHD than the nontea drinkers (P < 0.001). Adjustments for risk factors including age, gender, occupation, education, smoking, family history, blood lipids, diabetes, blood pressure, BMI, physical activity, and coffee and fat intake did not remove the significance (OR = 0.49; 95% CI = 0.24-0.96). There was a positive dose-response effect between tea consumption and CHD (P < 0.001) that was persistent after adjustment for various risk factors (P = 0.022). CONCLUSIONS These findings support a potential protective effect of tea consumption in relation to CHD in this Saudi study in which all tea consumed was black tea.
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Affiliation(s)
- Iman A Hakim
- Department of Biochemistry, College of Sciences, King Saud University, Riyadh, Saudi Arabia.
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Tokunaga S, White IR, Frost C, Tanaka K, Kono S, Tokudome S, Akamatsu T, Moriyama T, Zakouji H. Green tea consumption and serum lipids and lipoproteins in a population of healthy workers in Japan. Ann Epidemiol 2002; 12:157-65. [PMID: 11897173 DOI: 10.1016/s1047-2797(01)00307-6] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE To examine the relation between green tea consumption and serum lipids and lipoproteins. METHODS The subjects were 13,916 workers (8476 men and 5440 women) aged 40-69 years at over 1000 workplaces in Nagano prefecture, central Japan. They underwent health screening offered by a single medical institute between April 1995 and March 1996 and did not have morbid conditions affecting serum cholesterol levels. Serum concentrations of total cholesterol, high-density lipoprotein (HDL) cholesterol and triglycerides were measured at the screening. The consumption of green tea and other life-style characteristics were ascertained by a questionnaire. The data were analyzed with multivariate linear model. RESULTS Daily consumption of green tea was reported by 86.7% of subjects. Green tea consumption was, statistically, significantly associated with lower levels of serum total cholesterol in both men and women while its associations with serum triglycerides and HDL cholesterol were not statistically significant. The inverse association of serum total cholesterol with green tea consumption appeared to level off at the consumption of more than 10 cups/day. Excluding the outlying subjects drinking more than 10 cups/day (0.4%), the regression analysis adjusting for age, body mass index, ethanol intake, smoking habit, coffee intake, and type of work showed that daily consumption of one cup of green tea was associated with a reduction in serum total cholesterol by 0.015 mmol/L (95% confidence interval 0.006 to 0.024, p < 0.001) in men and 0.015 mmol/L (0.004 to 0.025, p < 0.01) in women. After additional adjustment for selected dietary factors, the inverse association remained statistically significant; one cup of green tea per day was associated with a reduction in serum total cholesterol by 0.010 mmol/L (0.001 to 0.019, p = 0.03) in men and 0.012 mmol/L (0.001 to 0.022, p = 0.03) in women. CONCLUSION Consumption of green tea was associated with lower serum concentration of total cholesterol in Japanese healthy workers age 40-69 years; however, green tea consumption was unrelated to serum HDL-cholesterol and triglycerides.
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Affiliation(s)
- Shoji Tokunaga
- Department of Preventive Medicine, Graduate School of Medical School of Medical Sciences, Kyushu University, Fukuoka, Japan.
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Flavonoids and cardiovascular diseases. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s1572-5995(01)80018-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
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Abstract
BACKGROUND The role of coffee consumption in the onset of myocardial infarction remains uncertain. A review of published reports showed that although cohort data suggest very little excess risk of coronary heart disease among habitual coffee drinkers, case-control data suggest an excess risk of the order of 60% for people drinking five or more cups per day. METHODS We obtained as much information as possible on the lifestyle and habits, including coffee consumption, of people admitted with chest pain to the Coronary Care Unit at the Royal Perth Hospital, Australia. A questionnaire was given to them by the attending nursing staff. Details were recorded by the patient, often with help from the nursing staff. A similar questionnaire was completed by patients attending the Cardiology Outpatient Clinic. RESULTS One of the outstanding differences between the 182 patients with myocardial infarction or unstable angina and 185 patients with chronic stable coronary heart disease who filled in forms while waiting in the Cardiology Outpatient Clinic was that more people with acute coronary syndromes were drinking in excess of five cups of coffee per day (18 vs 7.5%; P = 0.003). In logistic regression analysis adjusted for age, smoking status (past and current), hypertension, dyslipidaemia and diabetes, the odds ratio was 2.51 (95% CI 1.43,4.43; P = 0.021). CONCLUSION The present case-control study provides evidence for an increased risk of myocardial infarction or unstable angina among individuals drinking more than five cups of coffee per day.
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Affiliation(s)
- O B Tofler
- Cardiology Department and Coronary Care Unit, Royal Perth Hospital Perth, Western Australia, Australia
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Miura Y, Chiba T, Tomita I, Koizumi H, Miura S, Umegaki K, Hara Y, Ikeda M, Tomita T. Tea catechins prevent the development of atherosclerosis in apoprotein E-deficient mice. J Nutr 2001; 131:27-32. [PMID: 11208934 DOI: 10.1093/jn/131.1.27] [Citation(s) in RCA: 231] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Green tea contains various antioxidative flavan-3ols (tea catechins), such as (-)-epigallocatechin gallate (EGCg, the major catechin), which exert potent inhibitory effects on LDL oxidation in vitro and ex vivo in humans. In this study, the antiatherogenic effects of tea catechins were examined in atherosclerosis-susceptible C57BL/6J, apoprotein (apo)E-deficient mice. Male apoE-deficient mice (10 wk old) were fed an atherogenic diet for 14 wk; during that time, one group (tea) was supplied drinking water supplemented with green tea extract (0.8 g/L), and another group (control) was offered the vehicle only. The tea extract consisted of the following (g/100 g): EGCg, 58.4; (-)-epigallocatechin (EGC), 11.7; (-)-epicatechin (EC), 6.6; (-)-gallocatechingallate (GCg), 1.6; (-)-epicatechin gallate (ECg), 0.5; and caffeine, 0.4. The estimated actual intake of tea catechin was 1.7 mg/(d. mouse). Tea ingestion did not influence plasma cholesterol or triglyceride concentrations. Plasma lipid peroxides were reduced in the tea group at wk 8, suggesting that the in vivo oxidative state is improved by tea ingestion. Atheromatous areas in the aorta from the arch to the femoral bifurcation and aortic weights were both significantly attenuated by 23% in the tea group compared with the control group. Aortic cholesterol and triglyceride contents were 27 and 50% lower, respectively, in the tea group than in the control group. These results suggest that chronic ingestion of tea extract prevents the development of atherosclerosis without changing the plasma lipid level in apoE-deficient mice, probably through the potent antioxidative activity of the tea.
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Affiliation(s)
- Y Miura
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1, Yada, Shizuoka, 422-8526, Japan
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Miura Y, Chiba T, Miura S, Tomita I, Umegaki K, Ikeda M, Tomita T. Green tea polyphenols (flavan 3-ols) prevent oxidative modification of low density lipoproteins: an ex vivo study in humans. J Nutr Biochem 2000; 11:216-22. [PMID: 10827344 DOI: 10.1016/s0955-2863(00)00068-1] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Oxidation of low density lipoprotein (LDL) plays crucial roles in atherogenesis. We previously reported that green tea polyphenols (flavan 3-ols), especially epigallocatechingallate (EGCg) and epicatechingallate, exerted potent inhibitory effects on LDL oxidation in vitro. To examine whether intake of green tea polyphenols renders LDL resistant to ex vivo oxidation in humans, 22 male volunteers aged between 22 and 32 years were recruited and assigned the same dietary regimen for 2 weeks. After a 1-week baseline period, they were equally divided into two groups: control and tea. The tea group ingested 300 mg of green tea polyphenol extract twice daily for 1 week. Plasma EGCg concentration at the end of the experiment was 56 nmol/L on average (56% in free form) in the tea group; no EGCg was detected before the experiment. Plasma concentrations of lipids, ascorbate, alpha-tocopherol, and lipid peroxides did not change before and after the experiment in either group, but beta-carotene was higher in the tea group (P< 0.01 by paired Student'st-test). LDL (0.1 mg/mL) was incubated with 5 microM Cu(2+) and the oxidation was measured by absorbance at 234 nm. The lag time was significantly prolonged by 13.7 min in the tea group (P < 0.05 by paired Student'st-test, before versus after), whereas such a change was not observed in the control group. These results suggest that daily consumption of seven to eight cups (approximately 100 mL each cup) of green tea may increase resistance of LDL to in vivo oxidation, leading to reduction in the risk of cardiovascular diseases.
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Affiliation(s)
- Y Miura
- Department of Pharmaceutical Sciences, University of Shizuoka;, Shizuoka, Japan
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Woodward M, Tunstall-Pedoe H. Coffee and tea consumption in the Scottish Heart Health Study follow up: conflicting relations with coronary risk factors, coronary disease, and all cause mortality. J Epidemiol Community Health 1999; 53:481-7. [PMID: 10562866 PMCID: PMC1756940 DOI: 10.1136/jech.53.8.481] [Citation(s) in RCA: 145] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
STUDY OBJECTIVE To relate habitual (cups per day) tea and coffee consumption to conventional coronary risk factors and subsequent risk of coronary heart disease and death. DESIGN Cohort study. SETTING Nationwide random population study. PARTICIPANTS Over 11,000 men and women aged 40-59 who took part in the Scottish Heart Health Study lifestyle and risk factor survey in 1984-87. Participants were followed up to the end of 1993, an average of 7.7 years, for all cause mortality, coronary death, or any major coronary event (death, non-fatal infarction or coronary artery surgery). Cox's proportional hazards regression model was used to estimate the hazard in consumers of tea and coffee relative to the zero consumption group, both before and after correction for other factors. MAIN RESULTS Coffee and tea consumption showed a strong inverse relation. For many conventional risk factors, coffee showed a weak, but beneficial, gradient with increasing consumption, whereas increasing tea consumption showed the reverse. Increasing coffee consumption was associated with beneficial effects for mortality and coronary morbidity, whereas tea showed the opposite. Adjusting for age and social class had some effect in reducing associations. Multiple adjustment for other risk factors removed the associations for tea and most of those for coffee although there was a residual benefit of coffee consumption in avoiding heart disease among men. CONCLUSIONS The epidemiological differences shown in this study occurred despite the pharmacological similarities between tea and coffee. Either they differ more than is realised, or they identify contrasting associated lifestyle and health risks, for which this multiple adjustment was inadequate.
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Affiliation(s)
- M Woodward
- Department of Applied Statistics, University of Reading
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Cherubini A, Beal MF, Frei B. Black tea increases the resistance of human plasma to lipid peroxidation in vitro, but not ex vivo. Free Radic Biol Med 1999; 27:381-7. [PMID: 10468212 DOI: 10.1016/s0891-5849(99)00064-7] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A number of in vitro studies have shown that polyphenols and flavonoids in tea exert significant antioxidant activity. However, epidemiologic and experimental studies have produced conflicting results. The purpose of the present study was to compare the antioxidant activity of black tea in vitro with that ex vivo. Black tea polyphenols (BTP), black tea extract (BTE), or their major polyphenolic antioxidant constituent, epigallocatechin gallate (EGCG), were added to human plasma and lipid peroxidation was induced by the water-soluble radical generator 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH). Following a lag phase, lipid peroxidation was initiated and occurred at a rate that was lowered in a dose-dependent manner by BTP. Similarly, EGCG and BTE added to plasma in vitro strongly inhibited AAPH-induced lipid peroxidation. The lag phase preceding detectable lipid peroxidation was due to the antioxidant activity of endogenous ascorbate, which was more effective at inhibiting lipid peroxidation than the tea polyphenols and was not spared by these compounds. In contrast, when eight healthy volunteers consumed the equivalent of six cups of black tea, the resistance of their plasma to lipid peroxidation ex vivo did not increase over the next 3 h. These data suggest that, despite antioxidant efficacy in vitro, black tea does not protect plasma from lipid peroxidation in vivo. The striking discrepancy between the in vitro and ex vivo data is most likely explained by the insufficient bioavailability of tea polyphenols in humans.
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Affiliation(s)
- A Cherubini
- Neurochemistry Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, USA
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Chan PT, Fong WP, Cheung YL, Huang Y, Ho WK, Chen ZY. Jasmine green tea epicatechins are hypolipidemic in hamsters (Mesocricetus auratus) fed a high fat diet. J Nutr 1999; 129:1094-101. [PMID: 10356071 DOI: 10.1093/jn/129.6.1094] [Citation(s) in RCA: 213] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
These studies were designed to test the hypolipidemic activity of green tea epicatechins (GTE) isolated from jasmine green tea. In Experiment 1, three groups of hamsters were given a semisynthetic diet containing 200 g lard/kg and 1 g cholesterol/kg for 4 wk. The control group received distilled water, and the other two groups received either 15 g/L green tea water extract (GTWE) or 5.0 g/L GTE solution. Both the GTWE and GTE groups had lower concentrations of serum total cholesterol (TC) and triacylglycerols (TG) than the controls (P < 0.05). In Experiment 2, four groups of hamsters received tap water as the drinking fluid, but they were given the same high fat and cholesterol diet supplemented with 0 (control), 1.1, 3.4 or 5.7 g GTE/kg diet. The hypolipidemic effect of jasmine GTE was dose dependent. In Experiment 3, the time-course of changes in serum TC and TG was monitored in hamsters given the high fat diet supplemented with 5.7 g GTE/kg in comparison with that of controls. The hypolipidemic effects of dietary GTE were evident after feeding for 2 wk. Dietary supplementation of GTE did not affect liver fatty acid synthase. However, GTE-supplemented hamsters had higher fecal excretions of total fatty acids, neutral sterols and acidic sterols compared with the control group. In Experiment 4, hamsters were fed nonpurified diet; the control group drank distilled water, and the GTE group drank distilled water containing 5.0 g GTE/L. No differences in activities of 3-hydroxy-3-methyl glutaryl coenzyme A reductase and intestinal acyl CoA:cholesterol acyltransferase were observed. This study suggests that the hypolipidemic activity of GTE is not due to inhibition of synthesis of cholesterol or fatty acid but is most likely mediated by its influence on absorption of dietary fat and cholesterol.
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Affiliation(s)
- P T Chan
- Departments of Biochemistry and Physiology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, The People's Republic of China
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Miyake Y, Kono S, Nishiwaki M, Hamada H, Nishikawa H, Koga H, Ogawa S. Relationship of coffee consumption with serum lipids and lipoproteins in Japanese men. Ann Epidemiol 1999; 9:121-6. [PMID: 10037556 DOI: 10.1016/s1047-2797(98)00051-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE To examine the relationship of instant coffee and brewed coffee with serum lipids and lipoproteins in Japanese men. METHODS Study subjects were 4587 male self-defense officials aged 48-56 years who had a preretirement health examination at one of the three hospitals of the Self-Defense Forces from October 1986 to December 1992. A self-administered questionnaire ascertained lifestyle characteristics including consumption of a limited number of foods and beverages by all of the men. Serum concentrations of total cholesterol (TC), triglycerides (TG), and high density lipoprotein (HDL) cholesterol were measured, and low density lipoprotein (LDL) cholesterol levels were calculated from the values of TC, TG, and HDL cholesterol. RESULTS While the consumption of brewed coffee was unrelated to any parameter of serum lipids and lipoproteins, instant coffee consumption showed a highly significant positive association with serum LDL cholesterol levels and an inverse association with serum TG levels. After adjustment for body mass index, smoking, alcohol use, green tea consumption, rank, and hospital, for each cup of instant coffee per day, LDL cholesterol levels were 0.82 mg/dl (95% confidence interval (CI) 0.29-1.35) higher, and TG levels in a natural log-scale were 0.014 mg/dl (95% CI 0.006-0.022) lower. There was also a tendency for a positive association between instant coffee intake and serum TC levels (trend p = 0.09). HDL cholesterol levels were unrelated to instant coffee consumption. These associations did not change after additional adjustment for selected foods and beverages associated with serum lipids and lipoproteins. CONCLUSIONS The findings suggest that instant coffee, not brewed coffee, may be associated with raised levels of serum LDL cholesterol and decreased levels of serum TG.
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Affiliation(s)
- Y Miyake
- Department of Public Health, Faculty of Medicine, Kyushu University, Fukuoka, Japan
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Mazur WM, Wähälä K, Rasku S, Salakka A, Hase T, Adlercreutz H. Lignan and isoflavonoid concentrations in tea and coffee. Br J Nutr 1998; 79:37-45. [PMID: 9505801 DOI: 10.1079/bjn19980007] [Citation(s) in RCA: 124] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Tea is a beverage consumed widely throughout the world. The existence in tea of chemopreventing compounds possessing antimutagenic, anticarcinogenic and antioxidative properties has been reported. High intakes of tea and foods containing flavonoids have recently been shown to be negatively correlated to the occurrence of CHD. However, tea may contain other compounds with similar activities. Using a new gas chromatographic-mass spectrometric method we measured lignans and isoflavonoids in samples of twenty commercial teas (black, green and red varieties) and, for comparison, six coffees. Both unbrewed and brewed tea were investigated. The analysis of the teas yielded relatively high levels of the lignans secoisolariciresinol (5.6-28.9 mg/kg; 15.9-81.9 mumol/kg) and matairesinol (0.56-4.13 mg/kg; 1.6-11.5 mumol/kg) but only low levels of isoflavonoids. Because the plant lignans, as well as their mammalian metabolites enterolactone and enterodiol, have antioxidative properties and these mammalian lignans occur in high concentrations in plasma, we hypothesize that lignan polyphenols may contribute to the protective effect of tea on CHD.
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Affiliation(s)
- W M Mazur
- Department of Clinical Chemistry, University of Helsinki, Finland
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Tijburg LB, Mattern T, Folts JD, Weisgerber UM, Katan MB. Tea flavonoids and cardiovascular disease: a review. Crit Rev Food Sci Nutr 1997; 37:771-85. [PMID: 9447275 DOI: 10.1080/10408399709527802] [Citation(s) in RCA: 162] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- L B Tijburg
- Unilever Research Laboratorium, Vlaardingen, The Netherlands
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Hart C, Smith GD. Coffee consumption and coronary heart disease mortality in Scottish men: a 21 year follow up study. J Epidemiol Community Health 1997; 51:461-2. [PMID: 9328559 PMCID: PMC1060521 DOI: 10.1136/jech.51.4.461] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- C Hart
- Department of Public Health, University of Glasgow
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Bingham SA, Vorster H, Jerling JC, Magee E, Mulligan A, Runswick SA, Cummings JH. Effect of black tea drinking on blood lipids, blood pressure and aspects of bowel habit. Br J Nutr 1997; 78:41-55. [PMID: 9292758 DOI: 10.1079/bjn19970117] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Thirty-one men (47 (SD 14) years) and thirty-four women (35 (SD 13) years) took part in a 4-week randomized cross-over trial to compare the effect of six mugs of black tea daily v. placebo (water, caffeine, milk and sugar) on blood lipids, bowel habit and blood pressure, measured during a run-in period and at the end of weeks 2, 3 and 4 of the test periods. Compliance was established by adding a known amount of p-aminobenzoic acid (PABA) to selected tea bags, and then measuring its excretion in urine. Mean serum cholesterol values during run-in, placebo and on tea drinking were 5.67 (SD 1.05), 5.76 (SD 1.11) and 5.69 (SD 1.09) mmol/l (P = 0.16). There were also no significant changes in diet, LDL-cholesterol, HDL-cholesterol, triacylglycerols, and blood pressure in the tea intervention period compared with placebo. Compared with placebo, stool consistency was softened with tea (P = 0.04), and no other differences were found in bowel habit. Results were unchanged when fifteen 'non-compliers', whose PABA excretion indicated that fewer than six tea bags had been used, were excluded from the analysis, and when differences between run-in and tea periods were considered separately for those who were given tea first or second.
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Affiliation(s)
- S A Bingham
- Medical Research Council, Dunn Clinical Nutrition Centre, Cambridge
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Affiliation(s)
- M G Hertog
- Department of Chronic Diseases and Environmental Epidemiology, National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands
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Woodward M, Tunstall-Pedoe H. Alcohol consumption, diet, coronary risk factors, and prevalent coronary heart disease in men and women in the Scottish heart health study. J Epidemiol Community Health 1995; 49:354-62. [PMID: 7650458 PMCID: PMC1060122 DOI: 10.1136/jech.49.4.354] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
STUDY OBJECTIVE To measure the relationship between reported alcohol consumption and prevalent diagnosed and undiagnosed coronary heart disease (CHD) in men and women to see how much could be explained by covariation with diet, lifestyle, and biomedical factors. DESIGN AND SETTING This was a cross sectional, random population survey covering 22 districts of Scotland and using general practitioner patient lists as the sampling frame. Odds ratios for prevalent CHD at different levels of alcohol consumption taken from a seven day recall were analysed. These ratios were then adjusted for lifestyle and biomedical factors. PARTICIPANTS Male and female responders aged 40-59 years who completed the survey questionnaire and attended the survey clinic. MAIN RESULTS The participation rate of those invited was 74%. Of the 10,359 responders, 658 were excluded because of missing alcohol data or ambiguous cardiovascular status. The questionnaire was used to designate 7058 drinkers and 2643 non-drinkers, who were then classified as having diagnosed or undiagnosed CHD, or who were controls. The prevalence of diagnosed CHD decreased with increasing alcohol consumption while undiagnosed CHD had a "U" shaped relationship. Patterns were similar in men and women if allowance was made for the lower alcohol consumption in women. Adjustment for several diet and lifestyle factors and for additional biomedical factors reduced the apparent protective effect of alcohol, leaving a modest but statistically insignificant (p > 0.05) reduction in CHD prevalence among light to moderate consumers compared with those who drank no alcohol. Wine drinkers seemed to be at lower risk than beer drinkers in both sexes. CONCLUSIONS These results tend to confirm that intermediate alcohol consumption is a component and contributor to a low coronary risk lifestyle. Its effects are largely explained by adjusting for both confounding lifestyle associations and for biomedical effects but the remaining effect, and the lower risk with wine drinking compared with beer, are intriguing. Advice on alcohol habits should not be determined solely by the moderate apparent benefit to risk of CHD, however, as other disease risks cannot be ignored.
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Affiliation(s)
- M Woodward
- Cardiovascular Epidemiology Unit, Ninewells Hospital and Medical School, Dundee
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Streufert S, Pogash R, Miller J, Gingrich D, Landis R, Lonardi L, Severs W, Roache JD. Effects of caffeine deprivation on complex human functioning. Psychopharmacology (Berl) 1995; 118:377-84. [PMID: 7568623 DOI: 10.1007/bf02245937] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Twenty-five managers who reported an average daily caffeine consumption of 575 mg participated in two complex simulations. A double-blind cross-over design was employed to assess the effects of normal caffeine consumption versus caffeine deprivation upon seven validated measures of managerial effectiveness. Data from a Caffeine Withdrawal Questionnaire indicated discomfort upon deprivation. Systolic blood pressure increased during "normal" caffeine consumption levels but fell quickly and remained lower during deprivation. Several measures of managerial performance indicated decreased effectiveness upon caffeine deprivation. In contrast to prior research from simpler task settings, cognitive effectiveness (during complex task performance) was diminished. However, a measure of strategic performance which requires a relatively high level of cognitive effort showed no impact of caffeine deprivation.
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Affiliation(s)
- S Streufert
- Department of Behavioral Science, Pennsylvania State University, College of Medicine, Hershey 17033, USA
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Imai K, Nakachi K. Cross sectional study of effects of drinking green tea on cardiovascular and liver diseases. BMJ (CLINICAL RESEARCH ED.) 1995; 310:693-6. [PMID: 7711535 PMCID: PMC2549094 DOI: 10.1136/bmj.310.6981.693] [Citation(s) in RCA: 282] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVE To investigate the association between consumption of green tea and various serum markers in a Japanese population, with special reference to preventive effects of green tea against cardiovascular disease and disorders of the liver. DESIGN Cross sectional study. SETTING Yoshimi, Japan. SUBJECTS 1371 men aged over 40 years resident in Yoshimi and surveyed on their living habits including daily consumption of green tea. Their peripheral blood samples were subjected to several biochemical assays. RESULTS Increased consumption of green tea was associated with decreased serum concentrations of total cholesterol (P for trend < 0.001) and triglyceride (P for trend = 0.02) and an increased proportion of high density lipoprotein cholesterol together with a decreased proportion of low and very low lipoprotein cholesterols (P for trend = 0.02), which resulted in a decreased atherogenic index (P for trend = 0.02). Moreover, increased consumption of green tea, especially more than 10 cups a day, was related to decreased concentrations of hepatological markers in serum, aspartate aminotransferase (P for trend = 0.06), alanine transferase (P for trend = 0.07), and ferritin (P for trend = 0.02). CONCLUSION The inverse association between consumption of green tea and various serum markers shows that green tea may act protectively against cardiovascular disease and disorders of the liver.
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Affiliation(s)
- K Imai
- Department of Epidemiology, Saitama Cancer Center Research Institute, Japan
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