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Li J, Sun M, Cui X, Li C. Protective Effects of Flavonoids against Alzheimer's Disease: Pathological Hypothesis, Potential Targets, and Structure-Activity Relationship. Int J Mol Sci 2022; 23:ijms231710020. [PMID: 36077418 PMCID: PMC9456554 DOI: 10.3390/ijms231710020] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 08/22/2022] [Accepted: 08/26/2022] [Indexed: 11/20/2022] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disease with high morbidity and mortality, for which there is no available cure. Currently, it is generally believed that AD is a disease caused by multiple factors, such as amyloid-beta accumulation, tau protein hyperphosphorylation, oxidative stress, and inflammation. Multitarget prevention and treatment strategies for AD are recommended. Interestingly, naturally occurring dietary flavonoids, a class of polyphenols, have been reported to have multiple biological activities and anti-AD effects in several AD models owing to their antioxidative, anti-inflammatory, and anti-amyloidogenic properties. In this review, we summarize and discuss the existing multiple pathogenic factors of AD. Moreover, we further elaborate on the biological activities of natural flavonoids and their potential mode of action and targets in managing AD by presenting a wide range of experimental evidence. The gathered data indicate that flavonoids can be regarded as prophylactics to slow the advancement of AD or avert its onset. Different flavonoids have different activities and varying levels of activity. Further, this review summarizes the structure–activity relationship of flavonoids based on the existing literature and can provide guidance on the design and selection of flavonoids as anti-AD drugs.
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Affiliation(s)
- Jiao Li
- School of Life Science, Shanxi University, Taiyuan 030006, China
- Correspondence: (J.L.); (C.L.); Tel.: +86-351-701-9371 (J.L.); Fax: +86-351-701-1499 (J.L. & C.L.)
| | - Min Sun
- School of Life Science, Shanxi University, Taiyuan 030006, China
| | - Xiaodong Cui
- Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
| | - Chen Li
- School of Life Science, Shanxi University, Taiyuan 030006, China
- Correspondence: (J.L.); (C.L.); Tel.: +86-351-701-9371 (J.L.); Fax: +86-351-701-1499 (J.L. & C.L.)
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Fang C, Kim H, Barnes RC, Talcott ST, Mertens-Talcott SU. Obesity-Associated Diseases Biomarkers Are Differently Modulated in Lean and Obese Individuals and Inversely Correlated to Plasma Polyphenolic Metabolites After 6 Weeks of Mango (Mangifera indica L.) Consumption. Mol Nutr Food Res 2018; 62:e1800129. [PMID: 29797702 DOI: 10.1002/mnfr.201800129] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 05/03/2018] [Indexed: 01/24/2023]
Abstract
SCOPE Mangos are a rich source of gallotannin-derived polyphenols that may exert anti-inflammatory effects relevant to obesity-related chronic diseases. This randomized human clinical study investigated the influence of daily mango supplementation for 6 weeks on inflammation and metabolic functions in lean and obese individuals. METHODS AND RESULTS Lean (n = 12, body mass index [BMI] 18-26.2 kg m-2 ) and obese (n = 9, BMI >28.9 kg m-2 ) participants, aged 18-65 years received daily 400 g of mango pulp for 6 weeks. Inflammatory cytokines, metabolic hormones, and lipid profiles were examined in plasma before and after 6 weeks. In lean participants, systolic blood pressure was lowered by 4 mmHg after 6 weeks. In obese participants, hemoglobin A1c (HbA1c) and plasminogen activator inhibitor-1 (PAI-1) were reduced by 18% and 20%, respectively. Obese participants showed decreased plasma concentrations (area under the curve [AUC] 0-8h ) of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1). Correlation analysis indicates that the beneficial effects of mango supplementation on pro-inflammatory cytokines, PAI-1 and HbA1c, are associated with systemic exposure to polyphenolic metabolites. CONCLUSIONS Mango supplementation improves the plasma levels of pro-inflammatory cytokines and metabolic hormones in obese participants. There is a crucial need to investigate the role of lowered polyphenolic absorption in obese individuals on their efficacy in reducing biomarkers for inflammation and other risk factors for chronic diseases.
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Affiliation(s)
- Chuo Fang
- Department of Nutrition and Food Science, Texas A&M University, College Station, 77843, TX, USA
| | - Hyemee Kim
- Department of Nutrition and Food Science, Texas A&M University, College Station, 77843, TX, USA
| | - Ryan C Barnes
- Department of Nutrition and Food Science, Texas A&M University, College Station, 77843, TX, USA
| | - Stephen T Talcott
- Department of Nutrition and Food Science, Texas A&M University, College Station, 77843, TX, USA
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Orem A, Alasalvar C, Vanizor Kural B, Yaman S, Orem C, Karadag A, Pelvan E, Zawistowski J. Cardio-protective effects of phytosterol-enriched functional black tea in mild hypercholesterolemia subjects. J Funct Foods 2017. [DOI: 10.1016/j.jff.2017.01.048] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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Dower JI, Geleijnse JM, Gijsbers L, Schalkwijk C, Kromhout D, Hollman PC. Supplementation of the Pure Flavonoids Epicatechin and Quercetin Affects Some Biomarkers of Endothelial Dysfunction and Inflammation in (Pre)Hypertensive Adults: A Randomized Double-Blind, Placebo-Controlled, Crossover Trial. J Nutr 2015; 145:1459-63. [PMID: 25972527 DOI: 10.3945/jn.115.211888] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 04/10/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Consumption of flavonoid-rich foods such as cocoa and tea may reduce cardiovascular disease risk. The flavonoids epicatechin (in cocoa and tea) and quercetin (in tea) probably play a role by reducing endothelial dysfunction and inflammation, 2 main determinants of atherosclerosis. OBJECTIVE We studied the effects of supplementation of pure epicatechin and quercetin on biomarkers of endothelial dysfunction and inflammation. METHODS Thirty-seven apparently healthy (pre)hypertensive men and women (40-80 y) participated in a randomized, double-blind, placebo-controlled crossover trial. Participants ingested (-)-epicatechin (100 mg/d), quercetin-3-glucoside (160 mg/d), or placebo capsules for a period of 4 wk, in random order. Plasma biomarkers of endothelial dysfunction and inflammation were measured at the start and end of each 4-wk intervention period. The differences in changes over time between the intervention and placebo periods (Δintervention - Δplacebo) were calculated and tested with a linear mixed model for repeated measures. RESULTS Epicatechin changed Δepicatechin - Δplacebo for soluble endothelial selectin (sE-selectin) by -7.7 ng/mL (95% CI: -14.5, -0.83; P = 0.03) but did not significantly change this difference (-0.30; 95% CI: -0.61, 0.01; P = 0.06) for the z score for endothelial dysfunction. Quercetin changed Δquercetin - Δplacebo for sE-selectin by -7.4 ng/mL (95% CI: -14.3, -0.56; P = 0.03), that for IL-1β by -0.23 pg/mL (95% CI: -0.40, -0.06; P = 0.009), and that for the z score for inflammation by -0.33 (95% CI: -0.60, -0.05; P = 0.02). CONCLUSIONS In (pre)hypertensive men and women, epicatechin may contribute to the cardioprotective effects of cocoa and tea through improvements in endothelial function. Quercetin may contribute to the cardioprotective effects of tea possibly by improving endothelial function and reducing inflammation. This trial was registered at clinicaltrials.gov as NCT01691404.
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Affiliation(s)
- James I Dower
- Top Institute Food and Nutrition, Wageningen, The Netherlands; Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands; and
| | - Johanna M Geleijnse
- Top Institute Food and Nutrition, Wageningen, The Netherlands; Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands; and
| | - Lieke Gijsbers
- Top Institute Food and Nutrition, Wageningen, The Netherlands; Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands; and
| | - Casper Schalkwijk
- Top Institute Food and Nutrition, Wageningen, The Netherlands; Department of Internal Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Daan Kromhout
- Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands; and
| | - Peter C Hollman
- Top Institute Food and Nutrition, Wageningen, The Netherlands; Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands; and
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Bondonno CP, Croft KD, Ward N, Considine MJ, Hodgson JM. Dietary flavonoids and nitrate: effects on nitric oxide and vascular function. Nutr Rev 2015; 73:216-35. [PMID: 26024545 DOI: 10.1093/nutrit/nuu014] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Emerging evidence highlights dietary flavonoids and nitrate as candidates that may explain at least part of the cardioprotective effect of a fruit and vegetable diet. Nitric oxide plays a pivotal role in cardiovascular health. Components of a fruit and vegetable diet that are cardioprotective, in part through effects on nitric oxide status, could substantially reduce the cardiovascular risk profile of the general population with increased intake of such a diet. Epidemiological evidence suggests that dietary flavonoids and nitrate have a cardioprotective effect. Clinical trials with flavonoid- and nitrate-rich foods have shown benefits on measures of vascular health. While the molecular mechanisms by which flavonoids and nitrate are cardioprotective are not completely understood, recent evidence suggests both nonspecific and specific effects through nitric oxide pathways. This review presents an overview of nitric oxide and its key role in cardiovascular health and discusses the possible vascular benefits of flavonoids and nitrate, individually and in combination, through effects on nitric oxide status.
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Affiliation(s)
- Catherine P Bondonno
- C.P. Bondonno, K.D. Croft, N.C. Ward, and J.M. Hodgson are with the School of Medicine and Pharmacology, University of Western Australia, Perth Western Australia, Australia. M.J. Considine is with the School of Plant Biology, University of Western Australia, Perth Western Australia and the Department of Agriculture and Food Western Australia, Perth, Western Australia, Australia.
| | - Kevin D Croft
- C.P. Bondonno, K.D. Croft, N.C. Ward, and J.M. Hodgson are with the School of Medicine and Pharmacology, University of Western Australia, Perth Western Australia, Australia. M.J. Considine is with the School of Plant Biology, University of Western Australia, Perth Western Australia and the Department of Agriculture and Food Western Australia, Perth, Western Australia, Australia
| | - Natalie Ward
- C.P. Bondonno, K.D. Croft, N.C. Ward, and J.M. Hodgson are with the School of Medicine and Pharmacology, University of Western Australia, Perth Western Australia, Australia. M.J. Considine is with the School of Plant Biology, University of Western Australia, Perth Western Australia and the Department of Agriculture and Food Western Australia, Perth, Western Australia, Australia
| | - Michael J Considine
- C.P. Bondonno, K.D. Croft, N.C. Ward, and J.M. Hodgson are with the School of Medicine and Pharmacology, University of Western Australia, Perth Western Australia, Australia. M.J. Considine is with the School of Plant Biology, University of Western Australia, Perth Western Australia and the Department of Agriculture and Food Western Australia, Perth, Western Australia, Australia
| | - Jonathan M Hodgson
- C.P. Bondonno, K.D. Croft, N.C. Ward, and J.M. Hodgson are with the School of Medicine and Pharmacology, University of Western Australia, Perth Western Australia, Australia. M.J. Considine is with the School of Plant Biology, University of Western Australia, Perth Western Australia and the Department of Agriculture and Food Western Australia, Perth, Western Australia, Australia
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Yang CS, Chen G, Wu Q. Recent scientific studies of a traditional chinese medicine, tea, on prevention of chronic diseases. J Tradit Complement Med 2014; 4:17-23. [PMID: 24872929 PMCID: PMC4032838 DOI: 10.4103/2225-4110.124326] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Green tea (綠茶 Lǜ Chá), made from the leaves of the plant Camellia sinensis, has traditionally been used as a medicine in China for thousands of years. According to the classical work of Li Shizhen (李時珍 Lǐ Shí Zhēn) of the Ming Dynasty, “tea is cold and lowers the fire.” Since fire (inflammation) causes many diseases, could tea be effective in the prevention of many diseases? The possible prevention of chronic diseases such as cancer, metabolic syndrome, obesity, diabetes, and cardiovascular diseases has been studied with contemporary scientific methods, and the results are promising. The molecular mechanisms underlining these observations will be discussed in this presentation. One of the reasons for the failure to demonstrate a disease-preventive effect of tea in some epidemiological studies is the lower quantities of tea consumption in humans. Can we increase the quantity of tea consumption to harness its health benefits without causing gastrointestinal irritation? This is a topic for further research.
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Affiliation(s)
- Chung S Yang
- Department of Chemical Biology, Center for Cancer Prevention Research, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ, USA
| | - Gang Chen
- Department of Chemical Biology, Center for Cancer Prevention Research, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ, USA
| | - Qing Wu
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
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Gasper A, Hollands W, Casgrain A, Saha S, Teucher B, Dainty JR, Venema DP, Hollman PC, Rein MJ, Nelson R, Williamson G, Kroon PA. Consumption of both low and high (-)-epicatechin apple puree attenuates platelet reactivity and increases plasma concentrations of nitric oxide metabolites: a randomized controlled trial. Arch Biochem Biophys 2014; 559:29-37. [PMID: 24929184 DOI: 10.1016/j.abb.2014.05.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 05/19/2014] [Accepted: 05/31/2014] [Indexed: 02/05/2023]
Abstract
We hypothesised that consumption of flavanol-containing apple puree would modulate platelet activity and increase nitric oxide metabolite status, and that high flavanol apple puree would exert a greater effect than low flavanol apple puree. 25 subjects consumed 230 g of apple puree containing 25 and 100mg epicatechin (low and high flavanol apple puree, respectively) and aspirin (75 mg) in random order. Measurements were made at baseline, acutely after treatment (2, 6 and 24 h), and after 14 d of treatment. Low flavanol apple puree significantly attenuated ADP and epinephrine-induced integrin-β3 expression 2 h and 6 h after consumption and ADP and epinephrine-induced P-selectin expression within 2h of consumption. High flavanol apple puree attenuated epinephrine and ADP-induced integrin-β3 expression after 2 and 6h. ADP and epinephrine-induced integrin-β3 expression was significantly attenuated 2, 6 and 24 h after consumption of aspirin, whilst 14 d aspirin consumption attenuated collagen-induced P-selectin expression only. The plasma total nitric oxide metabolite conc. was significantly increased 6h after consumption of both low and high flavanol apple purees. In conclusion, consumption of apple purees containing ⩾25 or 100 mg flavanols transiently attenuated ex vivo integrin-β3 and P-selectin expression and increased plasma nitric oxide metabolite conc. in healthy subjects, but the effect was not enhanced for the high flavanol apple puree.
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Affiliation(s)
- Amy Gasper
- Food and Health Programme, Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK
| | - Wendy Hollands
- Food and Health Programme, Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK
| | - Amelie Casgrain
- Food and Health Programme, Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK
| | - Shikha Saha
- Food and Health Programme, Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK
| | - Birgit Teucher
- Food and Health Programme, Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK
| | - Jack R Dainty
- Food and Health Programme, Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK
| | - Dini P Venema
- RIKILT-Institute of Food Safety, Wageningen, The Netherlands
| | - Peter C Hollman
- RIKILT-Institute of Food Safety, Wageningen, The Netherlands
| | - Maarit J Rein
- Nestle Research Center, Vers-chez-les-Blanc, 1000 Lausanne 26, Switzerland
| | - Rebecca Nelson
- Nestle Research Center, Vers-chez-les-Blanc, 1000 Lausanne 26, Switzerland
| | - Gary Williamson
- Nestle Research Center, Vers-chez-les-Blanc, 1000 Lausanne 26, Switzerland; School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, UK
| | - Paul A Kroon
- Food and Health Programme, Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, UK.
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Bachmair EM, Ostertag LM, Zhang X, de Roos B. Dietary manipulation of platelet function. Pharmacol Ther 2014; 144:97-113. [PMID: 24858060 DOI: 10.1016/j.pharmthera.2014.05.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 05/05/2014] [Indexed: 01/24/2023]
Abstract
Activated platelets contribute to plaque formation within blood vessels in the early and late stages of atherogenesis, and therefore they have been proposed as risk factor for cardiovascular disease. Anti-platelet drugs, such as aspirin, are now the most prescribed pharmacological treatment in Europe. Certain dietary bioactives also beneficially affect platelet function, and with less side effects, albeit that effects are generally more subtle. Therefore, consumption of dietary bioactives could play a role in the prevention of atherothrombotic vascular disease. Here we review the efficacy of dietary treatment strategies, especially those involving certain dietary fatty acids and polyphenols, to modulate platelet function in healthy subjects or in patients with cardiovascular disease. Variation in study populations, small study sizes and lack of comparability between methods to assess platelet function currently limit robust evidence on the efficacy of dietary bioactives in healthy subjects or specific patient groups. Also, limited knowledge of the metabolism of dietary bioactives, and therefore of the bioavailability of bioactive ingredients, restricts our ability to identify the most effective dietary regimes to improve platelet function. Implementation of uniform point-of-care tests to assess platelet function, and enhanced knowledge of the efficacy by which specific dietary compounds and their metabolites affect platelet function, may enable the identification of functional anti-platelet ingredients that are eligible for a health claim, or combined treatment strategies, including both pharmacological anti-platelet treatment as well as dietary intervention, to tackle atherothrombotic vascular disease.
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Affiliation(s)
- E M Bachmair
- University of Aberdeen, Rowett Institute of Nutrition & Health, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, United Kingdom
| | - L M Ostertag
- University of Aberdeen, Rowett Institute of Nutrition & Health, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, United Kingdom
| | - X Zhang
- University of Aberdeen, Rowett Institute of Nutrition & Health, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, United Kingdom
| | - B de Roos
- University of Aberdeen, Rowett Institute of Nutrition & Health, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, United Kingdom.
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Yang CS, Hong J. Prevention of Chronic Diseases by Tea: Possible Mechanisms and Human Relevance. Annu Rev Nutr 2013; 33:161-81. [DOI: 10.1146/annurev-nutr-071811-150717] [Citation(s) in RCA: 137] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Chung S. Yang
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854-8020;
| | - Jungil Hong
- Department of Food Science and Technology, College of Natural Science, Seoul Women's University, Seoul, 139-774 Korea;
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Regular consumption of a cocoa product improves the cardiometabolic profile in healthy and moderately hypercholesterolaemic adults. Br J Nutr 2013; 111:122-34. [PMID: 23823716 DOI: 10.1017/s000711451300202x] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Cocoa products present great health potential due to their high content of polyphenols, mainly of flavanols. However, the antioxidant, anti-inflammatory and other health effects of regularly consuming cocoa products seem to depend on the intake and health status of the consumer, etc. and need to be further clarified. A randomised, controlled, cross-over, free-living study was carried out in healthy (n 24) and moderately hypercholesterolaemic (>2000 mg/l, n 20) subjects to assess the influence of regularly consuming (4 weeks) two servings (15 g each) of a cocoa product rich in fibre (containing 33·9 % of total dietary fibre (TDF) and 13·9 mg/g of soluble polyphenols) in milk v. consuming only milk (control) on (1) serum lipid and lipoprotein profile, (2) serum malondialdehyde levels, carbonyl groups, ferric reducing/antioxidant power, oxygen radical absorbance capacity and free radical-scavenging capacity, (3) IL-1β, IL-6, TNF-α, IL-10, IL-8, monocyte chemoattractant protein-1, and vascular and intracellular cell adhesion molecule levels, and (4) systolic and diastolic blood pressure and heart rate. Throughout the study, the diet and physical activity of the volunteers, as well as any possible changes in weight or other anthropometric parameters, were also evaluated. The intake of TDF increased (P< 0·001) to the recommended levels. Serum HDL-cholesterol (HDL-C) levels were increased (P< 0·001), whereas glucose (P= 0·029), IL-1β (P= 0·001) and IL-10 (P= 0·001) levels were decreased. The rest of the studied cardiovascular parameters, as well as the anthropometric ones, remained similar. In conclusion, regularly consuming a cocoa product with milk improves cardiovascular health by increasing HDL-C levels and inducing hypoglycaemic and anti-inflammatory effects in healthy and hypercholesterolaemic individuals without causing weight gain.
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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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Del Rio D, Rodriguez-Mateos A, Spencer JPE, Tognolini M, Borges G, Crozier A. Dietary (poly)phenolics in human health: structures, bioavailability, and evidence of protective effects against chronic diseases. Antioxid Redox Signal 2013; 18:1818-92. [PMID: 22794138 PMCID: PMC3619154 DOI: 10.1089/ars.2012.4581] [Citation(s) in RCA: 1545] [Impact Index Per Article: 140.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Human intervention trials have provided evidence for protective effects of various (poly)phenol-rich foods against chronic disease, including cardiovascular disease, neurodegeneration, and cancer. While there are considerable data suggesting benefits of (poly)phenol intake, conclusions regarding their preventive potential remain unresolved due to several limitations in existing studies. Bioactivity investigations using cell lines have made an extensive use of both (poly)phenolic aglycones and sugar conjugates, these being the typical forms that exist in planta, at concentrations in the low-μM-to-mM range. However, after ingestion, dietary (poly)phenolics appear in the circulatory system not as the parent compounds, but as phase II metabolites, and their presence in plasma after dietary intake rarely exceeds nM concentrations. Substantial quantities of both the parent compounds and their metabolites pass to the colon where they are degraded by the action of the local microbiota, giving rise principally to small phenolic acid and aromatic catabolites that are absorbed into the circulatory system. This comprehensive review describes the different groups of compounds that have been reported to be involved in human nutrition, their fate in the body as they pass through the gastrointestinal tract and are absorbed into the circulatory system, the evidence of their impact on human chronic diseases, and the possible mechanisms of action through which (poly)phenol metabolites and catabolites may exert these protective actions. It is concluded that better performed in vivo intervention and in vitro mechanistic studies are needed to fully understand how these molecules interact with human physiological and pathological processes.
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Affiliation(s)
- Daniele Del Rio
- The Laboratory of Phytochemicals in Physiology, Human Nutrition Unit, Department of Food Science, University of Parma, Parma, Italy
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Bøhn SK, Ward NC, Hodgson JM, Croft KD. Effects of tea and coffee on cardiovascular disease risk. Food Funct 2012; 3:575-91. [PMID: 22456725 DOI: 10.1039/c2fo10288a] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Tea and coffee have been associated with risk of cardiovascular disease (CVD), both positively and negatively. Epidemiological data suggest that black and green tea may reduce the risk of both coronary heart disease and stroke by between 10 and 20%. Experimental and clinical trial data generally indicate either neutral or beneficial effects on risk factors and pathways linked to the development of CVD. Controversy still exists regarding the effects of coffee, where there have been concerns regarding associations with hypercholesterolaemia, hypertension and myocardial infarction. However, long term moderate intake of coffee is not associated with detrimental effects in healthy individuals and may even protect against the risk of developing type 2 diabetes. The detrimental effects of coffee may be associated with the acute pressor effects, most likely due to caffeine at high daily intakes, and lipids from boiled coffee can contribute to raised serum cholesterol. Genetic polymorphisms in enzymes involved in uptake, metabolism and excretion of tea and coffee compounds are also associated with differential biological effects. Potential mechanisms by which tea and coffee phytochemicals can exert effects for CVD protection include the regulation of vascular tone through effects on endothelial function, improved glucose metabolism, increased reverse cholesterol transport and inhibition of foam cell formation, inhibition of oxidative stress, immunomodulation and effects on platelet function (adhesion and activation, aggregation and clotting). The phytochemical compounds in tea and coffee and their metabolites are suggested to influence protective endogenous pathways by modulation of gene-expression. It is not known exactly which compounds are responsible for the suggestive protective effects of tea and coffee. Although many biologically active compounds have been identified with known biological effects, tea and coffee contain many unidentified compounds with potential bioactivity.
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Affiliation(s)
- Siv K Bøhn
- School of Medicine and Pharmacology, The University of Western Australia-M570, 35 Stirling Highway, Crawley, WA 6009, Australia.
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Dell’agli M, Di Lorenzo C, Badea M, Sangiovanni E, Dima L, Bosisio E, Restani P. Plant Food Supplements with Anti-Inflammatory Properties: A Systematic Review (I). Crit Rev Food Sci Nutr 2012; 53:403-13. [DOI: 10.1080/10408398.2012.682123] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Mario Dell’agli
- a Department of Pharmacological and Biomolecular Sciences , Università degli Studi di Milano , Via Balzaretti 9, 20133 , Milano , Italy
| | - Chiara Di Lorenzo
- a Department of Pharmacological and Biomolecular Sciences , Università degli Studi di Milano , Via Balzaretti 9, 20133 , Milano , Italy
| | - Mihaela Badea
- b Faculty of Medicine , Transilvania University of Brasov, Str. Nicolae Balcescu 56 , Brasov , Romania
| | - Enrico Sangiovanni
- a Department of Pharmacological and Biomolecular Sciences , Università degli Studi di Milano , Via Balzaretti 9, 20133 , Milano , Italy
| | - Lorena Dima
- b Faculty of Medicine , Transilvania University of Brasov, Str. Nicolae Balcescu 56 , Brasov , Romania
| | - Enrica Bosisio
- a Department of Pharmacological and Biomolecular Sciences , Università degli Studi di Milano , Via Balzaretti 9, 20133 , Milano , Italy
| | - Patrizia Restani
- a Department of Pharmacological and Biomolecular Sciences , Università degli Studi di Milano , Via Balzaretti 9, 20133 , Milano , Italy
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Habauzit V, Morand C. Evidence for a protective effect of polyphenols-containing foods on cardiovascular health: an update for clinicians. Ther Adv Chronic Dis 2012; 3:87-106. [PMID: 23251771 PMCID: PMC3513903 DOI: 10.1177/2040622311430006] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Growing evidence suggests that polyphenols could be serious candidates to explain the protective effects of plant-derived foods and beverages. Based on current studies, a general consensus has been achieved to sustain the hypothesis that the specific intake of foods and beverages containing relatively high concentrations of flavonoids may play a meaningful role in reducing cardiovascular disease (CVD) risk through an improvement in vascular function and a modulation of inflammation. This review aims at providing an update on the effects of the consumption of polyphenols-rich foods on intermediate clinical markers of CVD in humans, namely cholesterolemia, blood pressure, endothelial function and platelet function. To date, on the basis of clinical studies, the demonstration is particularly convincing for flavonoids from cocoa-derived products and to a lesser extent for those of tea. While additional studies in this area are clearly needed, incorporating plant foods that are rich in flavanols in the diet of healthy individuals could help to reduce CVD risk. For flavonoids from fruits such as berries, pomegranate, grapes or citrus fruits and those from beverages such as red wine or coffee, the evidence is so far inconclusive. This is primarily due to the limited number and the weakness of experimental designs of the studies performed with these dietary sources. Future long-term well-designed investigations with polyphenols-rich foods but also with isolated phenolic compounds would provide valuable information to establish public health recommendations on polyphenols, taking into account both the nature of the compounds and the optimal dose, for cardiovascular health protection.
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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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17
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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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18
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Serafini M, Rio D, N’Dri Y, Bettuzzi S, Peluso I. Health Benefits of Tea. OXIDATIVE STRESS AND DISEASE 2011. [DOI: 10.1201/b10787-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Hodgson JM, Croft KD. Tea flavonoids and cardiovascular health. Mol Aspects Med 2010; 31:495-502. [PMID: 20837049 DOI: 10.1016/j.mam.2010.09.004] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 09/02/2010] [Accepted: 09/02/2010] [Indexed: 12/21/2022]
Abstract
The two main types of tea are green and black. Both green and black teas are rich dietary sources of flavonoids. Available evidence suggests that regular tea consumption may reduce the risk of cardiovascular disease. The cardiovascular health benefits of drinking tea are thought to be largely due to flavonoids. Tea intake and intake of flavonoids found in tea have been associated with reduced risk of cardiovascular disease in cross-sectional and prospective population studies. Isolated flavonoids found in tea have also been consistently shown to inhibit the development of atherosclerosis in animal models. A number of possible pathways and mechanisms have been investigated. There is now consistent data indicating that tea and tea flavonoids can enhance nitric oxide status and improve endothelial function, which may be at least partly responsible for benefits on cardiovascular health. There is also evidence, although limited, to suggest benefits of green tea (flavonoids) on body weight and body fatness. Data supporting reduced oxidative damage, inflammation, platelet activation, blood pressure, and risk of type 2 diabetes with tea (flavonoids) remains inadequate to draw any conclusions.
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Affiliation(s)
- Jonathan M Hodgson
- School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia, Australia.
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Abstract
Epidemiological evidence suggests that a high intake of plant foods is associated with lower risk of chronic diseases. However, the mechanism of action and the components involved in this effect have not been identified clearly. In recent years, the scientific community has agreed to focus its attention on a class of secondary metabolites extensively present in a wide range of plant foods: the flavonoids, suggested as having different biological roles. The anti-inflammatory actions of flavonoids in vitro or in cellular models involve the inhibition of the synthesis and activities of different pro-inflammatory mediators such as eicosanoids, cytokines, adhesion molecules and C-reactive protein. Molecular activities of flavonoids include inhibition of transcription factors such as NF-kappaB and activating protein-1 (AP-1), as well as activation of nuclear factor-erythroid 2-related factor 2 (Nrf2). However, the in vitro evidence might be somehow of limited impact due to the non-physiological concentrations utilized and to the fact that in vivo flavonoids are extensively metabolized to molecules with different chemical structures and activities compared with the ones originally present in the food. Human studies investigating the effect of flavonoids on markers of inflammation are insufficient, and are mainly focused on flavonoid-rich foods but not on pure molecules. Most of the studies lack assessment of flavonoid absorption or fail to associate an effect on inflammation with a change in circulating levels of flavonoids. Human trials with appropriate placebo and pure flavonoid molecules are needed to clarify if flavonoids represent ancillary ingredients or key molecules involved in the anti-inflammatory properties of plant foods.
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Affiliation(s)
- Francesco Violi
- Divisione I Clinica Medica, Università Sapienza, Viale del Policlinico 155, Roma, 00161, Italy.
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Ostertag LM, O'Kennedy N, Kroon PA, Duthie GG, de Roos B. Impact of dietary polyphenols on human platelet function - A critical review of controlled dietary intervention studies. Mol Nutr Food Res 2010; 54:60-81. [DOI: 10.1002/mnfr.200900172] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Nardini M, Natella F, Scaccini C. Role of dietary polyphenols in platelet aggregation. A review of the supplementation studies. Platelets 2009; 18:224-43. [PMID: 17497435 DOI: 10.1080/09537100601078083] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Epidemiological studies suggest that high polyphenols intake from diet is associated with reduced risk for cardiovascular diseases. Platelet aggregation is a crucial mechanism in the pathogenesis and clinical expression of coronary acute syndrome, and there is extensive evidence that antiplatelet therapy reduces cardiovascular disease risk. In this review, the available literature on the effect of polyphenols supplementation on platelet aggregation in humans or animal models has been critically analyzed, taking into consideration the different experimental protocols employed. In some studies, polyphenols supplementation did not show any effect on platelet aggregation. However, in the most of the studies, polyphenols supplementation, either as purified compounds or food extracts, showed some inhibitory effects, both in humans and in animal models. The extent of the inhibition varies in a wide range, depending on the experimental conditions used. The observed inhibitory effect of polyphenols on platelet aggregation might explain, at least in part, the epidemiological data on beneficial effect of dietary polyphenols on cardiovascular disease risk and suggests a role for polyphenols in helping to prevent cardiovascular diseases.
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Affiliation(s)
- Mirella Nardini
- National Research Institute for Food and Nutrition, Via Ardeatina 546, 00178 Roma - Italy.
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Mukamal KJ, MacDermott K, Vinson JA, Oyama N, Manning WJ, Mittleman MA. A 6-month randomized pilot study of black tea and cardiovascular risk factors. Am Heart J 2007; 154:724.e1-6. [PMID: 17892999 PMCID: PMC2084262 DOI: 10.1016/j.ahj.2007.07.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2007] [Accepted: 07/04/2007] [Indexed: 02/05/2023]
Abstract
BACKGROUND The effects of black tea consumption on cardiovascular risk factors have been inconsistent in previous randomized trials, all of which have been limited to a few weeks duration. METHODS We conducted a pilot parallel-design randomized controlled trial among 31 adults aged 55 years and older with either diabetes or 2 other cardiovascular risk factors but no established clinical cardiovascular disease. Participants were randomized to drink 3 glasses daily of either a standardized black tea preparation or water for 6 months. Cardiovascular risk factors were measured at the beginning and conclusion of the study. RESULTS Three participants dropped out of the study, leaving 14 participants assigned to tea and 14 assigned to water eligible for analyses. We found no statistically significant effects of black tea on cardiovascular biomarkers, including lipids, inflammatory markers, hemoglobin, adhesion molecules, prothrombotic and fibrinolytic parameters, and lipoprotein oxidizability. Assignment to tea did not appreciably influence blood pressure, and heart rate among participants assigned to tea was marginally higher than among control participants at 3 months (P = .07) but not 6 months. CONCLUSIONS In this randomized trial of black tea intake over 6 months among older adults with known cardiovascular risk factors, black tea did not appreciably influence any traditional or novel biomarkers of cardiovascular risk. Longer randomized trials are needed to verify the inverse association of tea with risk of cardiovascular disease seen in cohort studies and identify potential candidate mechanisms for such an association.
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Affiliation(s)
- Kenneth J Mukamal
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02446, USA.
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Ruel G, Pomerleau S, Couture P, Lemieux S, Lamarche B, Couillard C. Low-calorie cranberry juice supplementation reduces plasma oxidized LDL and cell adhesion molecule concentrations in men. Br J Nutr 2007; 99:352-9. [PMID: 17761017 DOI: 10.1017/s0007114507811986] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Elevated circulating concentrations of oxidized LDL (OxLDL) and cell adhesion molecules are considered to be relevant markers of oxidative stress and endothelial activation which are implicated in the development of CVD. On the other hand, it has been suggested that dietary flavonoid consumption may be cardioprotective through possible favourable impacts on LDL particle oxidation and endothelial activation. The present study was undertaken to determine the effect of the daily consumption of low-calorie cranberry juice cocktail on plasma OxLDL, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin concentrations in men. Thirty men (mean age 51 (sd 10) years) were recruited and asked to consume increasing daily doses of cranberry juice cocktail (125, 250 and 500 ml/d) over three successive periods of 4 weeks. Plasma OxLDL and adhesion molecule concentrations were measured by ELISA before and after each phase. We noted a significant decrease in plasma OxLDL concentrations following the intervention (P < 0.0001). We also found that plasma ICAM-1 (P < 0.0001) and VCAM-1 (P < 0.05) concentrations decreased significantly during the course of the study. In summary, the present results show that daily cranberry juice cocktail consumption is associated with decreases in plasma OxLDL, ICAM-1 and VCAM-1 concentrations in men.
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Affiliation(s)
- Guillaume Ruel
- Department of Food Science and Nutrition, Laval University, 2440 Boulevard Hochelaga, Québec, Canada G1K 7P4
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Steptoe A, Gibson EL, Vuononvirta R, Hamer M, Wardle J, Rycroft JA, Martin JF, Erusalimsky JD. The effects of chronic tea intake on platelet activation and inflammation: A double-blind placebo controlled trial. Atherosclerosis 2007; 193:277-82. [PMID: 17010979 DOI: 10.1016/j.atherosclerosis.2006.08.054] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2006] [Revised: 08/24/2006] [Accepted: 08/28/2006] [Indexed: 01/04/2023]
Abstract
BACKGROUND Tea drinking appears to protect against the development of coronary heart disease (CHD), but the mediating pathways are uncertain. We studied the effects of 6 weeks of black tea or placebo on platelet activation, C-reactive protein (CRP), total antioxidant status, and soluble (s) P-Selectin in a randomized double-blind trial. METHODS Healthy non-smoking men aged 18-55 years were randomized to black tea (N=37) or placebo (N=38) following a 4-week washout period during which they drank no tea, coffee or caffeinated beverages, but consumed caffeinated placebo tea. Bloods were drawn after 6 weeks of treatment. Platelet activation was assessed by measuring leukocyte-platelet aggregates using whole blood flow cytometry. RESULTS Following treatment, the tea group had fewer monocyte-platelet aggregates (means 5.84 versus 6.60%, P=0.027), neutrophil-platelet aggregates (P=0.017), total leukocyte-platelet aggregates (P=0.027), and lower plasma C-reactive protein (means 0.76 versus 0.97 mg/L, P=0.05) than the placebo group. There were no differences in total antioxidant status or soluble P-Selectin. CONCLUSIONS Chronic tea consumption reduces platelet activation and plasma C-reactive protein in healthy men. Effects cannot be attributed to observer bias or lifestyle confounders. These effects of tea may contribute to sustained cardiovascular health.
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Affiliation(s)
- Andrew Steptoe
- Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London WC1E 6BT, UK.
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Steptoe A, Gibson EL, Vuononvirta R, Williams ED, Hamer M, Rycroft JA, Erusalimsky JD, Wardle J. The effects of tea on psychophysiological stress responsivity and post-stress recovery: a randomised double-blind trial. Psychopharmacology (Berl) 2007; 190:81-9. [PMID: 17013636 DOI: 10.1007/s00213-006-0573-2] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2006] [Accepted: 08/09/2006] [Indexed: 10/24/2022]
Abstract
RATIONALE Tea has anecdotally been associated with stress relief, but this has seldom been tested scientifically. OBJECTIVES To investigate the effects of 6 weeks of black tea consumption, compared with matched placebo, on subjective, cardiovascular, cortisol and platelet responses to acute stress, in a parallel group double-blind randomised design. MATERIALS AND METHODS Seventy-five healthy nonsmoking men were withdrawn from tea, coffee and caffeinated beverages for a 4-week wash-out phase during which they drank four cups per day of a caffeinated placebo. A pretreatment laboratory test session was carried out, followed by either placebo (n = 38) or active tea treatment (n = 37) for 6 weeks, then, a final test session. Cardiovascular measures were obtained before, during and after two challenging behavioural tasks, while cortisol, platelet and subjective measures were assessed before and after tasks. RESULTS The tasks induced substantial increases in blood pressure, heart rate and subjective stress ratings, but responses did not differ between tea and placebo treatments. Platelet activation (assessed using flow cytometry) was lower following tea than placebo treatment in both baseline and post-stress samples (P < 0.005). The active tea group also showed lower post-task cortisol levels compared with placebo (P = 0.032), and a relative increase in subjective relaxation during the post-task recovery period (P = 0.036). CONCLUSIONS Compared with placebo, 6 weeks of tea consumption leads to lower post-stress cortisol and greater subjective relaxation, together with reduced platelet activation. Black tea may have health benefits in part by aiding stress recovery.
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Affiliation(s)
- Andrew Steptoe
- Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London, UK.
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De Bacquer D, Clays E, Delanghe J, De Backer G. Epidemiological evidence for an association between habitual tea consumption and markers of chronic inflammation. Atherosclerosis 2006; 189:428-35. [PMID: 16442546 DOI: 10.1016/j.atherosclerosis.2005.12.028] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Revised: 12/15/2005] [Accepted: 12/22/2005] [Indexed: 11/28/2022]
Abstract
BACKGROUND Tea consumption has been inversely related to the risk of cardiovascular disease, but the mechanism behind this cardioprotective role is not fully understood. In vitro and animal model studies suggest an anti-oxidative and/or anti-inflammatory role. We aimed at investigating the association between tea drinking and indicators of low-grade inflammation in humans. METHODS We used observational data from 1031 healthy men participating in a larger cross-sectional study (BELSTRESS). Tea consumption was determined according to a semi-quantitative food frequency questionnaire. Blood samples were analysed for C-reactive protein (CRP), serum amyloid A (SAA), serum haptoglobin and plasma fibrinogen. RESULTS Of all participants, 22% consumed tea regularly while 10% drank more than two cups per day. Tea drinkers were less obese, smoked less and drank less alcohol and coffee. CRP, SAA and haptoglobin were significantly associated with tea consumption, the effect being graded for SAA. Multivariate analysis did confirm the independence of the observed beneficial role of tea drinking. Fibrinogen levels were however not different between habitual tea consumers and non-consumers. Coffee drinking proved unrelated to chronic inflammation. CONCLUSION Tea drinking might be of interest in reducing the inflammatory process underlying cardiovascular disease. In light of the fact that tea is the most consumed beverage in the world after water, our findings might be of importance from a public health perspective.
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Affiliation(s)
- Dirk De Bacquer
- Department of Public Health, Ghent University, Ghent, Belgium.
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Holt RR, Actis-Goretta L, Momma TY, Keen CL. Dietary Flavanols and Platelet Reactivity. J Cardiovasc Pharmacol 2006; 47 Suppl 2:S187-96; discussion S206-9. [PMID: 16794457 DOI: 10.1097/00005344-200606001-00014] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Epidemiology studies suggest that the consumption of diets rich in flavonoids is associated with reduced risk of cardiovascular disease. Plant-derived foods and beverages, such as red wine, tea, grape and grape juice, cocoa and chocolate, can be rich in 1 particular class of flavonoid, the flavan-3-ols. There is now an increasing body of research that suggests that consuming flavanol-rich foods can positively affect hemostasis, through mechanisms that either directly affect platelet function or increase certain endothelium-derived factors that maintain platelet acquiescence or increase fibrinolysis. In this paper, we will review a series of in vivo studies on the effects of flavanol-rich cocoa and chocolate on platelet activation and platelet-dependent hemostasis. In addition, we will briefly review the body of literature with regard to other flavanol-rich foods and beverages, and possible mechanisms of action.
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Affiliation(s)
- Roberta R Holt
- Department of Nutrition, University of California, Davis, One Shields Ave, Davis, CA 95616, USA
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Hirano-Ohmori R, Takahashi R, Momiyama Y, Taniguchi H, Yonemura A, Tamai S, Umegaki K, Nakamura H, Kondo K, Ohsuzu F. Green Tea Consumption and Serum Malondialdehyde-Modified LDL Concentrations in Healthy Subjects. J Am Coll Nutr 2005; 24:342-6. [PMID: 16192258 DOI: 10.1080/07315724.2005.10719483] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Green tea was shown to inhibit LDL oxidation, platelet aggregation, and matrix metalloproteinases (MMPs) activities in vitro. We tried to elucidate whether or not green tea consumption may have these effects in vivo, which may be protective against atherosclerotic disease. METHODS We measured serum malondialdehyde-modified LDL (MDA-LDL) concentrations and urine 8-epi-prostaglandin (PG) F(2alpha) in 22 healthy male nonsmokers. They drank 7 cups/day of water for 2 weeks and drank 7 cups/day of green tea for the next 2 weeks. Regarding platelet aggregation, plasma thromboxane B(2) (TXB(2)) and 6-keto-PGF(1alpha) concentrations and ex vivo platelet aggregation were evaluated. Plasma MMP-2 and -9 concentrations were also measured. RESULTS Of the 22 subjects, 20 had been in the habit of drinking green tea before the study. Plasma catechins concentrations significantly decreased at the end of the water period and then increased at the end of the green tea period. Although no change in plasma LDL-cholesterol concentrations (110 +/- 33 vs. 113 +/- 28 mg/dL, p = NS) was found, MDA-LDL concentrations (84 +/- 45 vs. 76 +/- 40 IU/L, p < 0.05) and the ratio of MDA-LDL/LDL-cholesterol (0.74 +/- 0.21 vs. 0.65 +/- 0.20, p < 0.02) significantly decreased at the end of the green tea period. However, no significant changes were observed in urine 8-epi-PGF(2alpha) concentrations, in platelet aggregation, nor in plasma TXB(2), 6-keto-PGF(1alpha) or MMP concentrations. CONCLUSION Daily consumption of green tea decreased serum MDA-LDL concentrations, but it had no significant effects on platelet aggregation, platelet TX production or plasma MMPs concentrations. Our results suggest that green tea consumption may inhibit LDL oxidation in vivo.
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Affiliation(s)
- Reiko Hirano-Ohmori
- First Department of Internal Medicine, National Defense Medical College, Tokorozawa, Saitama 359-8513, Japan.
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Hodgson JM, Puddey IB. Dietary flavonoids and cardiovascular disease: does the emperor have any clothes? J Hypertens 2005; 23:1461-3. [PMID: 16003168 DOI: 10.1097/01.hjh.0000174609.64521.57] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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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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Abstract
PURPOSE OF REVIEW Polyphenols are the most abundant dietary antioxidants and research on their role in the prevention of degenerative diseases has developed quickly over these last few years. This paper reviews the recent studies on the prevention of cardiovascular diseases by polyphenols, focusing on human studies. RECENT FINDINGS A large number of recent intervention studies have shown that several biomarkers of cardiovascular risk are influenced by the consumption of polyphenol-rich foods. Effects on biomarkers of oxidative stress, lipemia and inflammation appear so far inconclusive. More consistent effects have been observed on endothelial function and haemostasis and support a reduction of risk by polyphenols in agreement with the few epidemiological studies already published. All clinical studies have used foods or beverages containing a mixture of different polyphenols and the exact nature of the most active compounds remains largely unknown. Absorption, metabolism and elimination vary widely between polyphenols. These data on bioavailability should be taken into account to improve the experimental design and the interpretation of the observed effects. SUMMARY Future intervention studies should include a detailed assessment of the bioavailability of polyphenols. Beyond clinical trials carried out with polyphenol-rich foods, more studies with pure polyphenols will also be needed to establish their role in the prevention of cardiovascular diseases.
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Affiliation(s)
- Claudine Manach
- Unité des Maladies Métaboliques et Micronutriments, INRA, 63122 Saint-Genès Champanelle, France
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Williamson G, Manach C. Bioavailability and bioefficacy of polyphenols in humans. II. Review of 93 intervention studies. Am J Clin Nutr 2005; 81:243S-255S. [PMID: 15640487 DOI: 10.1093/ajcn/81.1.243s] [Citation(s) in RCA: 811] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
For some classes of dietary polyphenols, there are now sufficient intervention studies to indicate the type and magnitude of effects among humans in vivo, on the basis of short-term changes in biomarkers. Isoflavones (genistein and daidzein, found in soy) have significant effects on bone health among postmenopausal women, together with some weak hormonal effects. Monomeric catechins (found at especially high concentrations in tea) have effects on plasma antioxidant biomarkers and energy metabolism. Procyanidins (oligomeric catechins found at high concentrations in red wine, grapes, cocoa, cranberries, apples, and some supplements such as Pycnogenol) have pronounced effects on the vascular system, including but not limited to plasma antioxidant activity. Quercetin (the main representative of the flavonol class, found at high concentrations in onions, apples, red wine, broccoli, tea, and Ginkgo biloba) influences some carcinogenesis markers and has small effects on plasma antioxidant biomarkers in vivo, although some studies failed to find this effect. Compared with the effects of polyphenols in vitro, the effects in vivo, although significant, are more limited. The reasons for this are 1) lack of validated in vivo biomarkers, especially in the area of carcinogenesis; 2) lack of long-term studies; and 3) lack of understanding or consideration of bioavailability in the in vitro studies, which are subsequently used for the design of in vivo experiments. It is time to rethink the design of in vitro and in vivo studies, so that these issues are carefully considered. The length of human intervention studies should be increased, to more closely reflect the long-term dietary consumption of polyphenols.
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Affiliation(s)
- Gary Williamson
- Nutrient Bioavailability Group, Nestlé Research Center, Lausanne, Switzerland.
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Lee W, Min WK, Chun S, Lee YW, Park H, Lee DH, Lee YK, Son JE. Long-term effects of green tea ingestion on atherosclerotic biological markers in smokers. Clin Biochem 2005; 38:84-7. [PMID: 15607322 DOI: 10.1016/j.clinbiochem.2004.09.024] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2003] [Revised: 09/20/2004] [Accepted: 09/27/2004] [Indexed: 11/18/2022]
Abstract
OBJECTIVES Smoking is a risk factor for coronary artery disease and triggers vascular injury by platelet aggregation and induces atherosclerosis through induction of oxidative stress. Green tea is known to have antioxidant capacity and anti-platelet activity. DESIGN AND METHODS Twenty adult male smokers ingested 600 mL of green tea for 4 weeks. Their lipid profile, C-reactive protein (CRP), total antioxidant capacity, oxidized LDL, soluble VCAM-1, soluble ICAM-1, and soluble P-selectin were measured at baseline and 2 and 4 weeks after green tea ingestion. RESULTS Plasma soluble P-selectin (sP-selectin) levels decreased significantly after 2 and 4 weeks of green tea ingestion compared with those before green tea ingestion (P < 0.001). Plasma concentrations of oxidized LDL decreased significantly after green tea ingestion (P < 0.05). CONCLUSIONS The results of this study suggest the effect of green tea on sP-selectin and oxidized LDL.
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Affiliation(s)
- Woochang Lee
- Department of Laboratory Medicine, Asan Medical Center and University of Ulsan College of Medicine, Songpa-Gu, Seoul, South Korea
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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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Ward NC, Croft KD, Puddey IB, Hodgson JM. Supplementation with grape seed polyphenols results in increased urinary excretion of 3-hydroxyphenylpropionic Acid, an important metabolite of proanthocyanidins in humans. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2004; 52:5545-5549. [PMID: 15315398 DOI: 10.1021/jf049404r] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Grape seed extract provides a concentrated source of polyphenols, most of which are proanthocyanidins. Polymeric proanthocyanidins are poorly absorbed in the small intestine of humans, and exposure may result from metabolism to phenolic acids by colonic bacteria. Any biological effects of proanthocyanidins may be due to the phenolic acid metabolites. Several phenolic acids have been identified as proanthocyanidin metabolites, but these may be derived from a range of other dietary sources. The aim of this study was to determine if 24-h urinary excretion of specific phenolic acids increased significantly and consistently following regular supplementation with grape seed extract. In a randomized, double-blind placebo-controlled trial, 69 volunteers received grape seed extract (1000 mg/day total polyphenols) or placebo for 6 weeks. Supplementation with grape seed polyphenols resulted in a consistent increase in the excretion of 3-hydroxyphenylpropionic acid (3-HPP, P < 0.001) and 4-O-methylgallic acid (P < 0.001) and a less consistent increase in the excretion of 3-hydroxyphenylacetic acid (P = 0.002). The observed increase in 3-HPP is in line with the suggestion that this compound is a major phenolic acid breakdown product of proanthocyanidin metabolism in vivo.
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Affiliation(s)
- Natalie C Ward
- School of Medicine and Pharmacology, University of Western Australia, and Western Australian Institute for Medical Research, Perth, Australia.
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Hodgson JM, Chan SY, Puddey IB, Devine A, Wattanapenpaiboon N, Wahlqvist ML, Lukito W, Burke V, Ward NC, Prince RL, Croft KD. Phenolic acid metabolites as biomarkers for tea- and coffee-derived polyphenol exposure in human subjects. Br J Nutr 2004; 91:301-6. [PMID: 14756917 DOI: 10.1079/bjn20031046] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Tea and coffee are rich in polyphenols with a variety of biological activities. Many of the demonstrated activities are consistent with favourable effects on the risk of chronic diseases. 4-O-methylgallic acid (4OMGA) and isoferulic acid are potential biomarkers of exposure to polyphenols derived from tea and coffee respectively. 4OMGA is derived from gallic acid in tea, and isoferulic acid is derived from chlorogenic acid in coffee. Our major objective was to explore the relationships of tea and coffee intake with 24 h urinary excretion of 4OMGA and isoferulic acid in human subjects. The relationships of long-term usual (111 participants) and contemporaneously recorded current (344 participants) tea and coffee intake with 24 h urinary excretion of 4OMGA and isoferulic acid were assessed in two populations. 4OMGA was related to usual (r 0.50, P<0.001) and current (r 0.57, P<0.001) tea intake, and isoferulic acid was related to usual (r 0.26, P=0.008) and current (r 0.18, P<0.001) coffee intake. Overall, our present results are consistent with the proposal that 4OMGA is a good biomarker for black tea-derived polyphenol exposure, but isoferulic acid may be of limited usefulness as a biomarker for coffee-derived polyphenol exposure.
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Affiliation(s)
- Jonathan M Hodgson
- University of Western Australia School of Medicine and Pharmacology, Royal Perth Hospital, Perth, Western Australia, Australia.
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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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Hodgson JM, Burke V, Beilin LJ, Croft KD, Puddey IB. Can black tea influence plasma total homocysteine concentrations? Am J Clin Nutr 2003; 77:907-11. [PMID: 12663290 DOI: 10.1093/ajcn/77.4.907] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Polyphenols can act as acceptors of methyl groups during the metabolism of methionine to homocysteine. This may result in elevations in plasma total homocysteine (tHcy) concentrations after ingestion of polyphenol-rich beverages such as tea. OBJECTIVES Our major objective was to determine whether regular, moderate-to-high intakes of black tea alter tHcy concentrations. We also assessed the relation between the degree of O-methylation of tea-derived polyphenols and the change in tHcy with regular ingestion of tea. DESIGN Twenty-two subjects completed a randomized, controlled crossover study. Subjects consumed 1250 mL black tea/d (5 cups each containing 2 g tea leaves in 250 mL boiled water) and 1250 mL hot water/d for 4 wk each. Fasting tHcy concentrations and 24-h urinary excretion of 4-O-methylgallic acid (4OMGA, the major O-methylated metabolite of gallic acid) were measured at the end of each period. 4OMGA was used as a marker of overall O-methylation of tea-derived polyphenols. RESULTS Black tea did not significantly alter mean (+/- SEM) tHcy concentrations (9.9 +/- 0.5 and 10.0 +/- 0.5 micro mol/L for the hot water and black tea periods, respectively). However, the increased excretion of 4OMGA as a consequence of black tea consumption was positively associated with the change in tHcy from the hot water period to the black tea period (r = 0.55, P = 0.008). Subjects in the bottom quartile of increase in 4OMGA excretion had a significant decrease in tHcy (-0.28 +/- 0.10 micro mol/L; P = 0.046), and those in the top quartile had a significant increase in tHcy (0.78 +/- 0.16 micro mol/L; P = 0.005). CONCLUSIONS Overall, regular ingestion of black tea did not alter mean tHcy concentrations. However, individual differences in O-methylation of polyphenolic compounds may influence the ultimate effects of black tea on tHcy.
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Affiliation(s)
- Jonathan M Hodgson
- School of Medicine & Pharmacology, University of Western Australia, and the Western Australian Institute for Medical Research, Royal Perth Hospital, Perth, Australia.
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Ó′Coinceanainn M, Astill C, Schumm S. Potentiometric, FTIR and NMR studies of the complexation of metals with theaflavin. Dalton Trans 2003. [DOI: 10.1039/b211102k] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Pearson DA, Paglieroni TG, Rein D, Wun T, Schramm DD, Wang JF, Holt RR, Gosselin R, Schmitz HH, Keen CL. The effects of flavanol-rich cocoa and aspirin on ex vivo platelet function. Thromb Res 2002; 106:191-7. [PMID: 12297125 DOI: 10.1016/s0049-3848(02)00128-7] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Flavanols modulate platelet function in vitro, but less is known of their in vivo effects and how they compare to pharmacological platelet inhibitors. We investigated the effect of a flavanol-rich cocoa beverage (897 mg/ml) in combination with and in comparison to aspirin on platelet function and activation in healthy subjects. METHODS AND RESULTS On separate test days in a crossover design, 16 healthy adults consumed aspirin (81 mg), cocoa (as a beverage), or aspirin plus cocoa. Platelet activation was measured by surface expression of P-selectin and PAC-1 binding to the activated conformation of the GPIIb/IIIa receptor (GPIIb/IIIa-act). Platelet function was measured on an analyzer (the PFA-100) that measures shear stress-induced platelet plug formation in response to collagen-epinephrine or collagen-ADP. Plasma epicatechin concentrations peaked approximately 2 h after subjects were given either the cocoa or aspirin plus cocoa. After 6 h, cocoa inhibited epinephrine-induced platelet function. Epinephrine-induced platelet function was inhibited 2 and 6 h after aspirin, and after aspirin plus cocoa. Epinephrine-stimulated P-selectin expression was inhibited by aspirin at 6 h, and after 2 and 6 h by aspirin plus cocoa. ADP-stimulated P-selectin expression was not affected by the treatments. Cocoa and aspirin, given separately, reduced epinephrine-stimulated GPIIb/IIIa-act expression at 2 and 6 h, respectively, and at 2 and 6 h when given together, suggesting an additive effective. ASA plus cocoa inhibited ADP-stimulated GPIIb/IIIa-act expression at 6 h. CONCLUSIONS Flavanol-rich cocoa inhibited epinephrine-stimulated platelet activation and function. These effects were qualitatively similar to aspirin, but less profound. These results emphasize the need to further examine the effects of food flavonoids for platelet modulating effects.
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Affiliation(s)
- Debra A Pearson
- Department of Human Biology, University of Wisconsin-Green Bay, ES 301, 2420 Nicolet Drive, Green Bay, WI 54311, USA.
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Hodgson JM, Puddey IB, Burke V, Beilin LJ, Mori TA, Chan SY. Acute effects of ingestion of black tea on postprandial platelet aggregation in human subjects. Br J Nutr 2002; 87:141-5. [PMID: 11895166 DOI: 10.1079/bjn2001499] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Results of population studies suggest that black tea can reduce cardiovascular risk. Effects of black-tea polyphenols to reduce platelet aggregability may help to explain any benefits. Given that black tea is often consumed with and after meals, and man spends much of his life in the postprandial state, the objective of the present study was to investigate the acute effects of ingestion of black tea on postprandial platelet aggregation ex vivo. Twenty healthy participants had platelet aggregation and blood lipids assessed before and 4 h after the ingestion of 50 g dairy fat on two occasions in random order, corresponding to black tea or hot water. Black tea or hot water (one cup) was consumed immediately following the dairy fat, then after 15 and 30 h. Platelet aggregation ex vivo was assessed in platelet-rich plasma in response to three concentrations of collagen (0.2, 0.6, 20 microg/ml) and ADP (2, 4, 8 microM). Urinary concentrations of 4-O-methylgallic acid were used as an indicator that tea polyphenols were absorbed. Serum total cholesterol and triacylglycerol concentrations increased significantly 4 h after ingesting the dairy fat, but there was no significant difference between black tea and hot-water treatments on the cholesterol or triacylglycerol responses. Urinary 4-O-methylgallic acid concentrations were significantly increased following ingestion of black tea (P=0.0001) but not water. Black tea in comparison to hot water did not inhibit collagen or ADP-induced postprandial platelet aggregation. The results of this study do not support the suggestion that reduced postprandial platelet aggregability contributes to any benefits of black tea on cardiovascular risk.
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Affiliation(s)
- Jonathan M Hodgson
- University of Western Australia Department of Medicine and HeartSearch, Royal Perth Hospital, Perth, Australia.
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Hodgson JM, Croft KD, Mori TA, Burke V, Beilin LJ, Puddey IB. Regular ingestion of tea does not inhibit in vivo lipid peroxidation in humans. J Nutr 2002; 132:55-8. [PMID: 11773508 DOI: 10.1093/jn/132.1.55] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Prospective studies suggest that tea may protect against cardiovascular disease. A potential mechanism for such an effect involves inhibition of lipid peroxidation by polyphenolic antioxidants derived from tea. Our objective was to determine whether regular ingestion of tea could inhibit in vivo lipid peroxidation. Two controlled intervention studies assessed the effects of regular ingestion of tea on lipid peroxidation determined by measurement of urinary F(2)-isoprostane excretion. Study 1: The effects of 1000 mL/d of green tea and black tea were compared with hot water containing caffeine in 13 subjects with elevated blood pressure using a randomized 3-period (7 d each) crossover design. Study 2: The effects of 1250 mL/d of black tea were compared with hot water in 22 subjects with mildly raised serum total cholesterol concentrations using a randomized 2-period (4 wk each) crossover design. F(2)-isoprostane excretion was not altered after regular ingestion of green tea (273 +/- 48 pmol/mmol creatinine) or black tea (274 +/- 39 pmol/mmol creatinine) in comparison with hot water (263 +/- 47 pmol/mmol creatinine; Study 1), or by regular ingestion of black tea (334 +/- 71 pmol/mmol creatinine) in comparison with hot water (355 +/- 75 pmol/mmol creatinine; Study 2). These results do not support the suggestion that polyphenolic antioxidants derived from tea inhibit in vivo lipid peroxidation.
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Affiliation(s)
- Jonathan M Hodgson
- University of Western Australia, Department of Medicine and HeartSearch, Royal Perth Hospital, Perth, WA 6001, Australia.
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