Green tea

Effect of green tea on the cardiovascular system

Type of study:

Number of citations: 0

Year: 2023

Authors: Jakub Maternia, Karolina Miszczyk, Patrycja Maj, Natalia Sergiel, Agata Kania, Malwina Gonet, Karolina Włodarczyk-Cybulska, Piotr Mozer, Michał Lazar, Aleksandra Serwik-Trandasir

Journal: Journal of Education, Health and Sport

Journal ranking: brak

Key takeaways: Green tea may help prevent cardiovascular diseases due to its antioxidative, anti-inflammatory, and anti-carcinogenic properties, and may have an inverse association with mortality from CVD.

Abstract: Cardiovascular diseases (CVD) are among the leading causes of mortality worldwide, causing significant public health concerns. Flavonoids, abundant in green tea, have been found to play a pivotal role in their prevention and treatment. These compounds exert beneficial effects on vascular endothelium through various mechanisms, including enhancing nitric oxide production, reducing LDL cholesterol levels, and inhibiting platelet aggregation. Dietary principles tailored to individual risk factors are also vital for individuals with CVD. Studies suggest that green tea may be a promising tool for preventing CVD due to its antioxidative, anti-inflammatory, anti-carcinogenic, and antiplatelet effects. Catechins in green tea have been demonstrated to modify various risk factors, thereby reducing overall CVD risk. Epidemiological studies have reported an inverse association between green tea consumption and mortality from CVD. The beneficial properties of green tea, especially among non-smokers and rural residents, underscore its potential role in managing CVD risk. Further research on the effect of green tea on vascular health is warranted.

The effects of green tea supplementation on cardiovascular risk factors: A systematic review and meta-analysis

Type of study: meta-analysis

Number of citations: 18

Year: 2023

Authors: M. Zamani, Mahnaz Rezaei Kelishadi, D. Ashtary-Larky, Niusha Amirani, K. Goudarzi, Iman Attackpour Torki, R. Bagheri, M. Ghanavati, Omid Asbaghi

Journal: Frontiers in Nutrition

Journal ranking: Q1

Key takeaways: Green tea supplementation improves lipid and glycemic profiles, supporting previous evidence showing health benefits on cardiometabolic risk factors.

Abstract: Purpose A bulk of observational studies have revealed the protective role of green tea supplementation in cardiovascular diseases. The current systematic review and meta-analysis study aimed to establish the effects of green tea supplementation on cardiovascular risk factors including lipid profile, blood pressure, glycemic control markers and CRP. Methods A systematic literature search of randomized clinical trials (RCTs) that investigated the effects of green tea supplementation and cardiovascular risk factors was undertaken in online databases including PubMed/Medline, Scopus, Web of Science, and Embase using a combination of green tea and cardiovascular risk factors search terms. Meta-analyses were carried out using a random-effects model. The I2 index was used to assess the heterogeneity of RCTs. Results Among the initial 11,286 studies that were identified from electronic databases search, 55 eligible RCTs with 63 effect sizes were eligible. Results from the random effects meta-analysis showed that GTE supplementation significantly reduced TC (WMD = −7.62; 95% CI: −10.51, −4.73; P = < 0.001), LDL-C (WMD = −5.80; 95% CI: −8.30, −3.30; P = < 0.001), FBS (WMD = −1.67; 95% CI: −2.58, −0.75; P = < 0.001), HbA1c (WMD = −0.15; 95% CI: −0.26, −0.04; P = 0.008), DBP (WMD = −0.87; 95% CI: −1.45, −0.29; P = 0.003), while increasing HDL-C (WMD = 1.85; 95% CI: 0.87, 2.84; P = 0.010). Subgroup analyses based on the duration of supplementation (≥ 12 vs. < 12 weeks), dose of green tea extract (GTE) (≥1,000 vs. < 1,000 mg/d), sex (male, female, and both), baseline serum levels of lipid profile, and glycemic control factors demonstrated different results for some risk factors. Conclusion The current study suggests improvements in the lipid and glycemic profiles following green tea supplementation. These findings support previous evidence showing the health benefits of green tea supplementation on cardiometabolic risk factors.

Green tea consumption and risk of cardiovascular and ischemic related diseases: A meta-analysis.

Type of study: meta-analysis

Number of citations: 118

Year: 2016

Authors: J. Pang, J. Pang, Zheng Zhang, T. Zheng, B. Bassig, Chen Mao, Xingbin Liu, Yong Zhu, K. Shi, J. Ge, Yuejin Yang, Dejia-Huang, M. Bai, Yu Peng

Journal: International journal of cardiology

Journal ranking: Q1

Key takeaways: Green tea consumption is associated with a reduced risk of cardiovascular and ischemic related diseases, with higher intake leading to even more favorable outcomes.

Mechanisms and effects of green tea on cardiovascular health.

Type of study:

Number of citations: 207

Year: 2007

Authors: A. Basu, E. Lucas

Journal: Nutrition reviews

Journal ranking: Q1

Key takeaways: Green tea, rich in antioxidants and anti-inflammatory catechins, may reduce cardiovascular disease risk factors and inflammation.

Abstract: Green tea, rich in antioxidant and anti-inflammatory catechins, especially epigallocatechin gallate (EGCG), has been shown to reduce surrogate markers of atherosclerosis and lipid peroxidation, particularly LDL oxidation and malondialdehyde concentrations, in several in vitro, animal, and limited clinical studies. Epidemiological observations in Southeast Asian countries indicate an inverse correlation exists between habitual consumption of green tea beverages and the incidence of cardiovascular events. A few short-term clinical studies have reported its effects in attenuating biomarkers of oxidative stress and inflammation among smokers, and an ability to decrease postprandial lipemia in hypercholesterolemic subjects has also been suggested. However, further investigations are needed to confirm the potential role of green tea beverages and the safety of green tea supplements in reducing body fat, as well as other biomarkers of cardiovascular disease risks.

Green tea catechins and cardiovascular health: an update.

Type of study:

Number of citations: 519

Year: 2008

Authors: P. V. A. Babu, Dongmin Liu

Journal: Current medicinal chemistry

Journal ranking: Q1

Key takeaways: Green tea catechins, the major polyphenolic compounds in green tea, exhibit vascular protective effects through multiple mechanisms, including antioxidative, anti-hypertensive, anti-inflammatory, and lipid lowering effects.

Abstract: Epidemiological, clinical and experimental studies have established a positive correlation between green tea consumption and cardiovascular health. Catechins, the major polyphenolic compounds in green tea, exert vascular protective effects through multiple mechanisms, including antioxidative, anti-hypertensive, anti-inflammatory, anti-proliferative, anti-thrombogenic, and lipid lowering effects. (1) Tea catechins present antioxidant activity by scavenging free radicals, chelating redox active transition-metal ions, inhibiting redox active transcription factors, inhibiting pro-oxidant enzymes and inducing antioxidant enzymes. (2) Tea catechins inhibit the key enzymes involved in lipid biosynthesis and reduce intestinal lipid absorption, thereby improving blood lipid profile. (3) Catechins regulate vascular tone by activating endothelial nitric oxide. (4) Catechins prevent vascular inflammation that plays a critical role in the progression of atherosclerotic lesions. The anti-inflammatory activities of catechins may be due to their suppression of leukocyte adhesion to endothelium and subsequent transmigration through inhibition of transcriptional factor NF-kB-mediated production of cytokines and adhesion molecules both in endothelial cells and inflammatory cells. (5) Catechins inhibit proliferation of vascular smooth muscle cells by interfering with vascular cell growth factors involved in atherogenesis. (6) Catechins suppress platelet adhesion, thereby inhibiting thrombogenesis. Taken together, catechins may be novel plant-derived small molecules for the prevention and treatment of cardiovascular diseases. This review highlights current developments in green tea extracts and vascular health, focusing specifically on the role of tea catechins in the prevention of various vascular diseases and the underlying mechanisms for these actions. In addition, the possible structure-activity relationship of catechins is discussed.

Impact of Green Tea Consumption on the Prevalence of Cardiovascular Outcomes: A Systematic Review

Type of study: systematic review

Number of citations: 6

Year: 2023

Authors: H. Tran, Mafaz Mansoor, S. Butt, T. Satnarine, P. Ratna, Aditi Sarker, Adarsh Srinivas Ramesh, Carlos Muñoz, Dawood Jamil, Lubna Mohammed

Journal: Cureus

Journal ranking: brak

Key takeaways: Green tea consumption significantly improves cardiovascular health by reducing cardiometabolic risks, hypercholesterolemia, and lowering blood pressure.

Abstract: Cardiovascular diseases (CVDs) represent a major global health concern, responsible for significant morbidity, mortality, and disability. To mitigate the impact of CVDs, individuals often seek preventive measures, and one such approach is the consumption of green tea. This study aims to provide a comprehensive and up-to-date assessment of the effects of green tea consumption on the prevalence of cardiovascular outcomes. Following PRISMA guidelines, we conducted a systematic review using PubMed and Google Scholar databases to identify relevant studies. Our analysis revealed that the risk factors associated with CVDs can vary across different diseases, with hypertension being a common risk factor for CVD mortality and CVD. Notably, the consumption of green tea exhibited a positive effect on reducing the prevalence of cardiometabolic risks and hypercholesterolemia. Furthermore, green tea consumption was observed to have a beneficial impact on lowering both diastolic and systolic blood pressure. In conclusion, the studies reviewed in this research suggest that the consumption of green tea has a significant and positive influence on cardiovascular health. These findings highlight the potential of green tea as a valuable component of a healthy lifestyle, offering a promising avenue for its use as a dietary supplement to reduce the risk of CVDs.

Effects of Green Tea on the Cardiovascular and Pulmonary System: A Review of Meta-Analyses and Systematic Reviews

Type of study: meta-analysis

Number of citations: 0

Year: 2025

Authors: Alireza Tajik, S. Ahmadi, Alireza Kashefizadeh, Sara Rashki Ghalehnoo

Journal: Journal of Zabol Medical School

Journal ranking: brak

Key takeaways: Green tea has anti-inflammatory, antioxidant, and anti-viral properties, which can help maintain cardiovascular health and strengthen the respiratory system.

Abstract: Background: Green tea is one of the most popular beverages in the world, especially in Asian countries. There is a common belief about the effects of green tea, including its impact on the cardiovascular and respiratory systems. Methods: In this review study, we selected systematic articles and meta-analyses for their comprehensive nature. Systematic articles and meta-analyses conducted in PubMed and Medline databases with keywords cardiopulmonary, green tea, cardiovascular disease, lung disease, and pulmonary disease from 2017 to 2024 were evaluated. In the end, nine articles were included in this study in terms of inclusion and exclusion criteria. Results: These studies have shown that green tea has anti-inflammatory, antioxidant, and anti-viral properties that can effectively prevent many diseases. Conclusion: Consuming green tea as a healthy and beneficial drink can help maintain the health of the cardiovascular system and strengthen the respiratory system.

Green tea catechins: defensive role in cardiovascular disorders.

Type of study: literature review

Number of citations: 102

Year: 2013

Authors: P. Bhardwaj, D. Khanna

Journal: Chinese journal of natural medicines

Journal ranking: Q1

Key takeaways: Green tea catechins can prevent cardiovascular disorders by decreasing oxidative stress, reducing inflammation, and enhancing vascular integrity and blood pressure.

Effects of Green Tea and EGCG on Cardiovascular and Metabolic Health

Type of study:

Number of citations: 374

Year: 2007

Authors: S. Wolfram

Journal: Journal of the American College of Nutrition

Journal ranking: Q2

Key takeaways: Regular consumption of 5-6 cups of green tea per day, containing 200-300 mg of EGCG, can provide pronounced cardiovascular and metabolic health benefits.

Abstract: Since ancient times green tea has been considered a health-promoting beverage. In recent years, scientists throughout the world have investigated the potential benefits of green tea and its most abundant catechin, epigallocatechin gallate (EGCG). The anti-cancer effects of green tea and EGCG were the focus of early research, and encouraging data from in vitro, animal model, and human studies have emerged. Due to the dominant role of cardiovascular disease and the dramatic rise of obesity and type 2 diabetes mellitus as major and interlinked healthcare problems, green tea and EGCG are increasingly being investigated in these areas. Dose-response relationships observed in several epidemiological studies have indicated that pronounced cardiovascular and metabolic health benefits can be obtained by regular consumption of 5–6 or more cups of green tea per day. Furthermore, intervention studies using similar amounts of green tea, containing 200–300 mg of EGCG, have demonstrated its usefulness for maintaining cardiovascular and metabolic health. Additionally, there are numerous in vivo studies demonstrating that green tea and EGCG exert cardiovascular and metabolic benefits in these model systems. Therefore, green tea and EGCG can be regarded as food components useful for the maintenance of cardiovascular and metabolic health. To prove the effectiveness for disease prevention or treatment, several multi-center, long-term clinical studies investigating the effects of one precisely-defined green tea product on cardiovascular and metabolic endpoints would be necessary. The aim of this manuscript is to provide an overview of the research investigating the effects of green tea and green tea catechins on cardiovascular and metabolic health.

The Impact of Green Tea Consumption on Cardiovascular Disease

Type of study: systematic review

Number of citations: 0

Year: 2024

Authors:

Journal: Pakistan Journal of Medical and Health Sciences

Journal ranking: brak

Key takeaways: Regular green tea consumption may improve blood lipid profiles, reduce blood pressure, and enhance endothelial function, potentially reducing cardiovascular risk factors.

Abstract: Aims: Cardiovascular diseases (CVDs) remain one of the leading causes of morbidity and mortality worldwide. Recent studies have highlighted the potential benefits of dietary interventions, particularly green tea, in the prevention and management of CVDs. This systematic review aims to evaluate the existing literature on the impact of green tea consumption on cardiovascular disease outcomes. Methodology: A systematic review was conducted, including a total of 20 studies that examined the relationship between green tea intake and various cardiovascular risk factors. The bioactive compounds in green tea, such as catechins and flavonoids, were analyzed for their antioxidant, anti-inflammatory, and lipid-lowering effects. Results: The findings suggest that regular green tea consumption may contribute to improved blood lipid profiles, reduced blood pressure, and enhanced endothelial function, all of which are critical for reducing cardiovascular risk. Conclusion: Green tea shows promising potential in mitigating cardiovascular risk factors. However, further high-quality randomized controlled trials (RCTs) are needed to confirm these benefits and establish optimal dosages for effective prevention and management of CVDs.

Green tea from the far east to the drug store: focus on the cardiovascular beneficial effects.

Type of study: literature review

Number of citations: 5

Year: 2020

Authors: L. Landini, E. Rebelos, Miikka-Juhani Honka

Journal: Current pharmaceutical design

Journal ranking: Q2

Key takeaways: Green tea consumption may reduce cardiovascular disease risk, with potential biological mechanisms and safety concerns regarding green tea extracts.

Abstract: Cardiovascular diseases(CVD) are the leading cause of death worldwide. Evidence from observational and randomized controlled studies showing the potential benefits of green tea on lowering CVD risk has been emerging rapidly during the past few decades.These benefits include reduced risk for major cardiovascular events, lowering of blood pressure, decreased LDL cholesterollevels and weight loss.At the same time, the understanding of physiological mechamismsbehind these alterations is advancing.Consumption of green tea originates from China thousands of years ago, but has since expanded all over the world.Recent advances in understanding the role of tea polyphenols, mainly catechins,as mediators of tea's health benefits has caused an emergence of various types of green teaextracts(GTE) on the market. While drinking green tea is generally considered safe, there are concerns about thesafety of using tea extracts. The present article reviews the current evidence of green tea consumption leading to reducedCVD risk, the phenomenon's potential biological mechanisms and the safety of using GTE.

Beneficial effects of green tea: A literature review

Type of study: literature review

Number of citations: 940

Year: 2010

Authors: Sabu M Chacko, Priya T Thambi, R. Kuttan, I. Nishigaki

Journal: Chinese Medicine

Journal ranking: Q1

Key takeaways: Green tea has health benefits for various ailments, including cancer, heart disease, and liver disease, and its catechin content may help treat metabolic syndrome and reduce the risk of coronary disease.

Abstract: The health benefits of green tea for a wide variety of ailments, including different types of cancer, heart disease, and liver disease, were reported. Many of these beneficial effects of green tea are related to its catechin, particularly (-)-epigallocatechin-3-gallate, content. There is evidence from in vitro and animal studies on the underlying mechanisms of green tea catechins and their biological actions. There are also human studies on using green tea catechins to treat metabolic syndrome, such as obesity, type II diabetes, and cardiovascular risk factors. Long-term consumption of tea catechins could be beneficial against high-fat diet-induced obesity and type II diabetes and could reduce the risk of coronary disease. Further research that conforms to international standards should be performed to monitor the pharmacological and clinical effects of green tea and to elucidate its mechanisms of action.

The effects of regular consumption of green or black tea beverage on blood pressure in those with elevated blood pressure or hypertension: A systematic review and meta-analysis.

Type of study: meta-analysis

Number of citations: 59

Year: 2020

Authors: M. Mahdavi-Roshan, A. Salari, Zeinab Ghorbani, A. Ashouri

Journal: Complementary therapies in medicine

Journal ranking: Q1

Key takeaways: Regular consumption of green or black tea can positively affect blood pressure in individuals with elevated blood pressure or hypertension, with green tea showing more pronounced effects.

The acute effect of green tea consumption on endothelial function in healthy individuals

Type of study: non-rct experimental

Number of citations: 136

Year: 2008

Authors: N. Alexopoulos, C. Vlachopoulos, K. Aznaouridis, K. Baou, C. Vasiliadou, P. Pietri, P. Xaplanteris, Elli Stefanadi, C. Stefanadis

Journal: European Journal of Preventive Cardiology

Journal ranking: Q1

Key takeaways: Green tea consumption has an acute beneficial effect on endothelial function in healthy individuals, potentially contributing to its beneficial effect on cardiovascular risk.

Abstract: Background Tea consumption is associated with decreased cardiovascular risk. Flow-mediated dilatation (FMD) of the brachial artery is related to coronary endothelial function and it is an independent predictor of cardiovascular risk. Black tea has a beneficial effect on endothelial function; the effect, however, of green tea on brachial artery reactivity has not been defined yet. Design and methods We studied 14 healthy individuals (age 30 ± 3 years) with no cardiovascular risk factors except from smoking (50%) on three separate occasions on which they took: (a) 6 g of green tea, (b) 125 mg of caffeine (the amount contained in 6 g of tea), or (c) hot water. FMD of the brachial artery was measured before each intervention and 30, 90, and 120 min afterward. High-sensitivity C-reactive protein, interleukins 6 (II-6) and 1 b (II-1b), total plasma antioxidative capacity, and total plasma oxidative status/stress were measured at baseline and at 120 min after each intervention. Results Resting and hyperemic brachial artery diameter did not change either with tea or with caffeine. FMD increased significantly with tea (by 3.69%, peak at 30 min, P < 0.02), whereas it did not change significantly with caffeine (increase by 1.72%, peak at 30 min, P = NS). Neither tea nor caffeine had any effect on high-sensitivity C-reactive protein, II-6, II-1 b, total plasma antioxidative capacity, or total plasma oxidative status/stress. Conclusion Green tea consumption has an acute beneficial effect on endothelial function, assessed with FMD of the brachial artery, in healthy individuals. This may be involved in the beneficial effect of tea on cardiovascular risk.

Green and black tea for the primary prevention of cardiovascular disease.

Type of study: meta-analysis

Number of citations: 215

Year: 2013

Authors: L. Hartley, N. Flowers, J. Holmes, Aileen Clarke, S. Stranges, Lee Hooper, Karen Rees

Journal: The Cochrane database of systematic reviews

Journal ranking: Q1

Key takeaways: Green and black tea both significantly reduce total cholesterol, LDL cholesterol, and blood pressure, potentially aiding in the primary prevention of cardiovascular disease.

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.

Acute cognitive, mood and cardiovascular effects of green and black tea

Type of study: rct

Number of citations: 1

Year: 2020

Authors: A. Scholey, A. Burns, M. Pase, A. Pipingas

Journal: Proceedings of the Nutrition Society

Journal ranking: Q1

Key takeaways: Green tea improves alertness, while black tea increases central systolic pressure, suggesting non-caffeine mechanisms or caffeine/non-caffeine compound interactions.

Abstract: Abstract Tea is often described as having “refreshing” properties. Indeed, components of both green and black tea have been shown to acutely improve aspects of cognition and mood and to affect cardiovascular function. There is, however, surprising little research directly comparing these effects between different types of tea. This study therefore examined acute cognitive, mood, and cardiovascular effects of green tea and black tea. A double blind, randomised, placebo-controlled,balanced, three-way cross-over study was conducted. Fourteen healthy young adults (M = 23.8, SD = 3 years) consumed placebo (water), green tea and black tea in balanced order at least 24 h apart.The drinks were prepared according to standardised procedures and consumed under double-blind conditions (in opaque containers with lemon cordial added for taste-masking). Mood and cognition were measured at baseline then 90 min post-treatment, cardiovascular function was assessed post-dose only. Mood was evaluated using a series of visual analogue scales, cognitive performance was assessed using a suite of standardised tests from the Computerised Mental Performance Assessment System (COMPASS), gauging performance on aspects of attention, memory and executive function.Peripheral and central systolic and diastolic pressure,augmentation pressure, augmentation index,and blood flow velocity were measured via Sphygmocor pulse wave analysis and Doppler ultrasound, respectively. There were a number of significant effects associated with the active treatments. Compared with placebo, black tea and green tea was associated with significantly improved digit vigilance accuracy (p < .01), while green tea was associated with higher alertness (p < .05).Regarding cardiovascular outcomes, black tea and green tea significantly increased central diastolic pressure, and peripheral diastolic pressure in comparison to placebo (P < .01). Black tea also significantly increased central systolic pressure compared to green tea and placebo (p < .05). Analysis of treatment guessing suggested that the masking procedure was highly effective. In conclusion, the present study shows that green tea improves alertness. Since black tea contains higher levels of caffeine, this effect is likely underpinned by non-caffeine mechanisms or caffeine/non-caffeine compound interactions.Improved vigilance is consistent with caffeine effects which may be modulated by cardiovascular effects. Interestingly the cardiovascular effects are opposite to those reported for chronic tea interventions. These results suggest that acute cognitive and cardiovascular components of tea merit further investigation both in the presence and absence of caffeine.

Tea in cardiovascular health and disease: a critical appraisal of the evidence

Type of study: literature review

Number of citations: 23

Year: 2022

Authors: Klaus W. Lange

Journal: Food Science and Human Wellness

Journal ranking: Q1

Key takeaways: Tea's protective role in cardiovascular health is supported by polyphenols, but current research lacks sufficient evidence to recommend optimal tea consumption levels for preventing hypertension and improving cardiovascular health.

Green tea reverses endothelial dysfunction in healthy smokers

Type of study: rct

Number of citations: 90

Year: 2004

Authors: N. Nagaya, H. Yamamoto, M. Uematsu, T. Itoh, K. Nakagawa, T. Miyazawa, K. Kangawa, K. Miyatake

Journal: Heart

Journal ranking: Q1

Key takeaways: Green tea consumption reverses endothelial dysfunction and improves oxidative stress in healthy smokers, potentially reducing cardiovascular risk.

Abstract: Green tea is popular in Asia, including Japan, although it is rarely consumed by western people. It contains large amounts of catechins which are potent free radical scavengers and therefore has an antioxidant effect.1 Oxidative stress participates in the pathogenesis of many cardiovascular diseases. Recently, black tea consumption has been shown to reverse endothelial dysfunction in patients with coronary artery disease through its antioxidant effects.2 However, the number of catechins in non-fermented tea (green tea) is higher than that in fermented tea (black tea).1 These findings raise the possibility that green tea acts as a potent antioxidant. Smoking is a well recognised risk factor for cardiovascular diseases. Free radicals in cigarette smoke are responsible for endothelial dysfunction, leading to atherosclerosis.3 Earlier studies have shown that the flavonoid components of red wine and purple grape juice, which are powerful antioxidants, reverse endothelial dysfunction and reduce cardiovascular risk. However, any beneficial effect of green tea on vascular function in smokers remains unknown. Accordingly, the purpose of this study was to investigate whether green tea consumption reverses endothelial dysfunction in association with improvement of oxidative stress in healthy smokers. We studied 20 healthy male smokers (mean (SEM) age 33 (1) years, body mass index 22.9 (0.9) kg/m2, smoking 15.5 (2.1) packs/year). They were randomised to consume green tea or hot water in a crossover design. All subjects gave written informed consent and the …

Green tea and cancer and cardiometabolic diseases: a review of the current epidemiological evidence

Type of study: systematic review

Number of citations: 66

Year: 2020

Authors: S. Abe, M. Inoue

Journal: European Journal of Clinical Nutrition

Journal ranking: Q1

Key takeaways: Green tea consumption may be beneficial for human health, with a majority of meta-analyses showing an inverse association with certain cancers and a generally positive association with cardiovascular disease and blood pressure outcomes.

Preventive effects of drinking green tea on cancer and cardiovascular disease: epidemiological evidence for multiple targeting prevention.

Type of study: non-rct observational study

Number of citations: 427

Year: 2000

Authors: K. Nakachi, S. Matsuyama, Satoshi Miyake, M. Suganuma, K. Imai

Journal: BioFactors

Journal ranking: Q1

Key takeaways: Drinking over 10 cups of green tea daily significantly reduces the risk of cancer and cardiovascular disease, with significant delays in cancer onset and life-prolonging effects.

Abstract: The significance of drinking green tea in prevention of two of the main lifestyle-related diseases, cancer and cardiovascular disease, was demonstrated in terms of a prospective cohort study on a total of 8,552 general residents in Saitama Prefecture, Japan. On the basis of the follow-up study, we revealed decreased relative risk of cancer incidence for those consuming over 10 cups a day, compared with those consuming below 3 cups: 0.54 (95% confidence interval, 0.22-1.34) for men, 0.57 (0.34-0.98) for women, and 0.59 (0.35-0.98) for both sexes. Furthermore, a significant delay in cancer onset was associated with increased consumption of green tea. Next, decreased relative risk of death from cardiovascular disease was 0.58 (0.34-0.99) for men, 0.82 (0.49-1.38) for women, and 0.72 (0.60-1.04) for members of both sexes consuming over 10 cups a day. Finally, we evaluated the life-prolonging effects of drinking green tea on cumulative survival, using the life table.

Therapeutic Activity of Green Tea Epigallocatechin-3-Gallate on Metabolic Diseases and Non-Alcoholic Fatty Liver Diseases: The Current Updates

Type of study: literature review

Number of citations: 43

Year: 2023

Authors: Armachius James, Ke Wang, Yousheng Wang

Journal: Nutrients

Journal ranking: Q1

Key takeaways: EGCG, the most abundant green tea polyphenol, shows potential in alleviating metabolic diseases and non-alcoholic fatty liver diseases through its antioxidant, anti-inflammatory, and weight-reducing effects.

Abstract: Green tea polyphenols have numerous functions including antioxidation and modulation of various cellular proteins and are thus beneficial against metabolic diseases including obesity, type 2 diabetes, cardiovascular and non-alcoholic fatty liver diseases, and their comorbidities. Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenol in green tea and is attributed to antioxidant and free radical scavenging activities, and the likelihood of targeting multiple metabolic pathways. It has been shown to exhibit anti-obesity, anti-inflammatory, anti-diabetic, anti-arteriosclerotic, and weight-reducing effects in humans. Worldwide, the incidences of metabolic diseases have been escalating across all age groups in modern society. Therefore, EGCG is being increasingly investigated to address the problems. This review presents the current updates on the effects of EGCG on metabolic diseases, and highlights evidence related to its safety. Collectively, this review brings more evidence for therapeutic application and further studies on EGCG and its derivatives to alleviate metabolic diseases and non-alcoholic fatty liver diseases.

Polyphenol-rich green tea extract improves adipose tissue metabolism by down-regulating miR-335 expression and mitigating insulin resistance and inflammation.

Type of study: non-rct experimental

Number of citations: 68

Year: 2018

Authors: R. Otton, A. Bolin, Letícia Torres Ferreira, M. P. Marinovic, A. Rocha, M. Mori

Journal: The Journal of nutritional biochemistry

Journal ranking: Q1

Key takeaways: Green tea improves adipose tissue metabolism and reduces inflammation by down-regulating miR-335 expression, which links inflammation to impaired metabolism in obesity.

Effect of Acute and Chronic Dietary Supplementation with Green Tea Catechins on Resting Metabolic Rate, Energy Expenditure and Respiratory Quotient: A Systematic Review

Type of study: systematic review

Number of citations: 13

Year: 2021

Authors: M. Rondanelli, A. Riva, G. Petrangolini, P. Allegrini, S. Perna, M. Faliva, G. Peroni, M. Naso, M. Nichetti, Federica Perdoni, C. Gasparri

Journal: Nutrients

Journal ranking: Q1

Key takeaways: Green tea catechins may improve metabolic profiles and reduce respiratory quotient, but further investigations are needed to determine adequate doses.

Abstract: The consumption of green tea catechins (GTC) is associated with modulations of fat metabolism and consequent weight loss. The aim of this systematic review was to investigate the effect of GTC on resting metabolic rate (RMR), energy expenditure (EE), and respiratory quotient (RQ). Eligible studies considered both the chronic and acute intake of GTC-based supplements, with epigallocatechin gallate (EGCG) doses ranging between 100–800 mg. Findings from 15 studies (n = 499 participants) lasting 8–12 weeks (for chronic consumption) or 1–3 days (for acute intake) are summarized. This review reveals the positive effects of GTC supplementation on RQ values (272 subjects). Regarding the effects of acute and chronic GTC supplementation on RMR (244 subjects) and EE (255 subjects), the results did not allow for a definitive conclusion, even though they were promising, because some reported a positive improvement (two studies revealed an increase in RMR: one demonstrated an RMR increase of 43.82 kcal/day and another demonstrated an increase of 260.8 kcal/day, mainly when subjects were also engaged in resistance training exercise). Considering GTC daily dose supplementation, studies in which modifications of energetic parameters occurred, in particular RQ reduction, considered GTC low doses (100–300 mg). GTC may be useful for improving metabolic profiles. Further investigations are needed to better define adequate doses of supplementation.

Weight control and prevention of metabolic syndrome by green tea.

Type of study: literature review

Number of citations: 204

Year: 2011

Authors: Sudathip Sae‐tan, Kimberly A. Grove, J. Lambert

Journal: Pharmacological research

Journal ranking: Q1

Key takeaways: Green tea and its component EGCG show promising preventive effects against metabolic syndrome symptoms, including obesity, insulin resistance, hypertension, and hypercholesterolemia.

A minireview of effects of green tea on energy expenditure

Type of study:

Number of citations: 49

Year: 2017

Authors: D. Türközü, N. Tek

Journal: Critical Reviews in Food Science and Nutrition

Journal ranking: Q1

Key takeaways: Green tea's caffeine and catechin components increase energy expenditure, potentially aiding in weight loss through thermogenesis and fat oxidation.

Abstract: ABSTRACT In recent years, individuals have begun to tend more frequently to some natural and herbal products to be used alone or as a combination with diet and exercise for ensuring the weight loss. Green tea is the leading one of these products. In some studies, it is reported that the green tea causes an increase in thermogenesis and substrate with fat oxidation by affecting on the sympathetic nervous system. It is reported that green tea has two main components that are associated with energy expenditure. One of them is caffeine and the other is catechin content. Each of these two components has an impact on energy mechanism separately. In this minireview article, mechanisms of action and effects of caffeine and catechin, which are found in green tea composition, on energy expenditure are assessed.

The intestinal-level metabolic benefits of green tea catechins: Mechanistic insights from pre-clinical and clinical studies.

Type of study: systematic review

Number of citations: 14

Year: 2023

Authors: Dwinder Sidhu, M. Vasundhara, Priyankar Dey

Journal: Phytomedicine : international journal of phytotherapy and phytopharmacology

Journal ranking: Q1

Key takeaways: Green tea catechins' metabolic health benefits are influenced by intestinal-level bioactivities, including reduced inflammation, gut barrier dysfunction, and improved lipid absorption and metabolism.

Effects of green tea on lipid metabolism in overweight or obese people: A meta‐analysis of randomized controlled trials

Type of study: meta-analysis

Number of citations: 35

Year: 2018

Authors: Fen Yuan, Hui Dong, Ke Fang, Jing Gong, F. Lu

Journal: Molecular Nutrition & Food Research

Journal ranking: Q1

Key takeaways: Drinking green tea significantly lowers plasma total cholesterol and low-density lipoprotein cholesterol levels in overweight or obese people, but its effect on triglyceride and HDL levels remains unclear.

Abstract: SCOPE The effects of green tea on lipid metabolism were inconsistent. The objective of this meta-analysis was to evaluate the effects of green tea on lipid metabolism in overweight or obese people. METHODS AND RESULTS We searched randomized controlled trials (RCTs) comparing green tea with a control on lipid metabolism on PUBMED and WEB OF SCIENCE (January 1990 to September 2016), COCHRANE and EMBASE (updated to October 2016), and the Chinese databases CNKI, WanFang and CBMD. Twenty-one articles studying 1704 overweight or obese subjects were selected for this meta-analysis. The pooled results demonstrated that green tea significantly decreased plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL) levels in overweight or obese people. The weighted mean difference was -3.38 mg/dl for TC (95% CI: -6.42,  -0.33 mg/dL) and -5.29 mg/dL for LDL (95% CI: -7.92, -2.6 6 mg/dL), respectively. Green tea intake, however, showed no effect on plasma triglyceride (TG) and high-density lipoprotein cholesterol(HDL) levels in overweight or obese people with a relatively high heterogeneity. CONCLUSION The meta-analysis shows that drinking green tea can lower plasma TC and LDL levels significantly. Nevertheless, green tea's effect on plasma TG and HDL must be further evaluated by additional high-quality and large-scale RCTs.

Mechanisms of body weight reduction and metabolic syndrome alleviation by tea.

Type of study: literature review

Number of citations: 321

Year: 2016

Authors: Chung S. Yang, Jinsong Zhang, Le Zhang, Jinbao Huang

Journal: Molecular nutrition & food research

Journal ranking: Q1

Key takeaways: Drinking three to four cups of tea per day can reduce body weight and alleviate metabolic syndrome, with green tea being more effective than black tea.

Abstract: Tea, a popular beverage made from leaves of the plant Camellia sinensis, has been shown to reduce body weight, alleviate metabolic syndrome, and prevent diabetes and cardiovascular diseases in animal models and humans. Such beneficial effects have generally been observed in most human studies when the level of tea consumption was three to four cups (600-900 mg tea catechins) or more per day. Green tea is more effective than black tea. In spite of numerous studies, the fundamental mechanisms for these actions still remain unclear. From a review of the literature, we propose that the two major mechanisms are: (i) decreasing absorption of lipids and proteins by tea constituents in the intestine, thus reducing calorie intake; and (ii) activating AMP-activated protein kinase by tea polyphenols that are bioavailable in the liver, skeletal muscle, and adipose tissues. The relative importance of these two mechanisms depends on the types of tea and diet consumed by individuals. The activated AMP-activated protein kinase would decrease gluconeogenesis and fatty acid synthesis and increase catabolism, leading to body weight reduction and metabolic syndrome alleviation. Other mechanisms and the health relevance of these beneficial effects of tea consumption remain to be further investigated.

Potential role of green tea extract and epigallocatechin gallate in preventing bisphenol A-induced metabolic disorders in rats: Biochemical and molecular evidence.

Type of study: rct

Number of citations: 15

Year: 2021

Authors: Mahdieh Sadat Mohsenzadeh, B. Razavi, M. Imenshahidi, Seyed Abbas Tabatabaee Yazdi, S. A. Mohajeri, H. Hosseinzadeh

Journal: Phytomedicine : international journal of phytotherapy and phytopharmacology

Journal ranking: Q1

Key takeaways: Green tea extract and EGCG can effectively prevent or reduce metabolic disorders induced by bisphenol A, due to their antioxidant and anti-inflammatory properties, regulating lipid metabolism, and improving insulin signaling pathways.

Effect of green tea on hepatic lipid metabolism in mice fed a high-fat diet.

Type of study:

Number of citations: 41

Year: 2018

Authors: M. Nam, Myung‐Sook Choi, Ji-Young Choi, Nami Kim, Min-Sun Kim, Sunhee Jung, Juyeon Kim, D. Ryu, G. Hwang

Journal: The Journal of nutritional biochemistry

Journal ranking: Q1

Key takeaways: Green tea consumption can improve lipid metabolism in obese mice, potentially reducing inflammation associated with obesity.

Green tea polyphenols modify gut-microbiota dependent metabolisms of energy, bile constituents and micronutrients in female Sprague-Dawley rats.

Type of study: non-rct experimental

Number of citations: 49

Year: 2018

Authors: Jun Zhou, L. Tang, Chwan-Li Shen, Jia-Sheng Wang

Journal: The Journal of nutritional biochemistry

Journal ranking: Q1

Key takeaways: Green tea polyphenols alter gut-microbiota metabolism, reducing calorific carbohydrates, increasing vitamin production, decreasing bile constituents, and modifying amino acid metabolism in female Sprague-Dawley rats.

Effects of tea consumption on metabolic syndrome: A systematic review and meta‐analysis of randomized clinical trials

Type of study: meta-analysis

Number of citations: 25

Year: 2020

Authors: Wei Liu, Chunpeng Wan, Yingjie Huang, Mingxi Li

Journal: Phytotherapy Research

Journal ranking: Q1

Key takeaways: Tea consumption has protective effects on metabolic syndrome, with black tea reducing blood pressure and green tea reducing diabetes and LDL cholesterol.

Abstract: The metabolic syndrome (MetS) is one of the major health hazards and an epidemic worldwide. There is no known best remedy has been defined yet. In the current investigation, we designed a meta‐analysis of randomized clinical trials (RCTs) to evaluate the beneficial effects of tea consumption in alleviating metabolic syndromes. Herein, we accumulated the relevant literature available on PubMed and EMBASE databases from January, 2000 to August, 2019. RCTs bearing impact factor of at least 1 or more were studied for the effect of tea consumption on MetS. This meta‐analysis suggested that tea consumption has beneficial effects on diastolic blood pressure (DBP), and this finding was characterized of all types of tea in the current study and also for body mass index (BMI) value. Furthermore, this analysis also found that black tea consumption has protective effects on systolic SBP, green tea reduces the incidence of diabetes and lower the level of low‐density lipoprotein (LDL) cholesterol. These functions required BMI value at least 28 or higher. The meta data led us to conclude that tea consumption have protective effects on MetS, however, different types of tea might have different protective mechanisms on MetS, but, exact mechanisms are not yet clear and needs to be explored.

Green tea minimally affects biomarkers of inflammation in obese subjects with metabolic syndrome.

Type of study: rct

Number of citations: 197

Year: 2011

Authors: A. Basu, M. Du, K. Sanchez, M. Leyva, N. Betts, S. Blevins, Mingyuan Wu, C. Aston, T. Lyons

Journal: Nutrition

Journal ranking: Q2

Key takeaways: Green tea consumption for 8 weeks did not affect metabolic syndrome features but significantly reduced plasma serum amyloid alpha, a cardiovascular disease risk factor, in obese subjects.

The Role of Green Tea on the Regulation of Gut Microbes and Prevention of High-Fat Diet-Induced Metabolic Syndrome in Mice

Type of study: non-rct experimental

Number of citations: 7

Year: 2023

Authors: Huiling Mei, Jin Li, Shujing Liu, Anburaj Jeyaraj, Z. Jing, Yuhua Wang, Xuan Chen, Qijun Yuan, Xinghui Li

Journal: Foods

Journal ranking: Q1

Key takeaways: Green tea promotes weight loss and regulates gut microbes, potentially preventing high-fat diet-induced metabolic syndrome in obese mice.

Abstract: Green tea is a popular non-alcoholic beverage consumed worldwide and has been shown to be beneficial for human health. However, further exploration is needed to fully understand its function in reducing obesity and regulating gut microbes. Here, we investigated the modulatory effects of green tea and its functional components on high-fat diet (HF)-induced metabolic alterations and gut microbiota in obese mice. Our results showed that 1%, 2%, and 4% of green tea promotes weight loss, with the 2% and 4% groups exhibiting distinct gut microflora clusters compared to the HF group. These results were comparable to those observed in the tea polyphenols (TPP)-treated group, suggesting the TPP in green tea plays a crucial role in body weight control and gut microbiota regulation. Additionally, 32 bacteria were identified as potential obesity markers via 16S rRNA gene sequencing. The 16SrDNA gene is a chromosomal gene present in all bacterial species, highly conserved in structure and function, that can reflect the differences between different taxa. The 16S rRNA-based analysis revealed that Akkermansia, a gut-beneficial bacteria, significantly increased in the TPP group.

Green Tea Ameliorates Depression-Like Behavior and Cognitive Impairment Induced by High-Fat Diet and Chronic Mild Stress.

Type of study: non-rct experimental

Number of citations: 0

Year: 2025

Authors: Minghao Fan, Yudi Jiang, Chao Cai, Zhe Wang, Lu Chen, Shumin Hu, Xin Zhang, Hua Yin, Zhonghua Qian, Shuli Huang, Jiachen Yang

Journal: Phytotherapy research : PTR

Journal ranking: Q1

Key takeaways: Long-term green tea consumption improves mood, memory, and lipid metabolism in stress-induced depression-like behavior and cognitive impairment in mice.

Abstract: Depression often develops in young individuals and is linked to complications like cognitive impairment. Conventional antidepressants show limited efficacy in restoring cognitive function and may cause adverse effects. Green tea, a safe and health-promoting beverage, offers various health benefits. This study investigated the effects of long-term green tea consumption on stress-induced depression-like behavior and mild cognitive impairment in animal models. We established a rodent model of mild depression and studied the effects of green tea on depression-like behavior and cognitive impairment through comprehensive evaluation, including behavioral assessments, neurotransmitter quantification, gene and protein expression analysis, blood metabolite profiling, and gut microbiota characterization. Results demonstrated significant improvements in mood, long-term memory, and sterol and glycerophospholipid metabolism. Green tea repaired the intestinal barrier and upregulated genes vital for tight junctions and mucin production. It also enhanced gut microbiota composition, reducing the Firmicutes-to-Bacteroidetes ratio and promoting beneficial bacteria such as NK4A136, Muribaculum, and Gordonibacter. These microbiota changes improved liver lipid metabolism and alleviated depressive symptoms. Green tea effectively mitigates depression-like behavior and cognitive deficits by modulating the gut-liver-brain axis.

Effect of Green Tea Supplementation on Inflammatory Markers among Patients with Metabolic Syndrome and Related Disorders: A Systematic Review and Meta-Analysis

Type of study: meta-analysis

Number of citations: 2

Year: 2024

Authors: Fernanda Souza de Oliveira Assis, Gabriel Lima Vasconcellos, Diego José Pereira Lopes, Leandro Roberto de Macedo, Maísa Silva

Journal: Preventive Nutrition and Food Science

Journal ranking: Q2

Key takeaways: Green tea supplementation significantly lowers TNF- levels in patients with metabolic syndrome and related disorders, but does not affect CRP or IL-6 levels.

Abstract: Several randomized controlled trials (RCTs) have investigated the potential benefits of green tea on the inflammatory process in metabolic syndrome (MetS). However, the results are inconclusive and inconsistent. In the present study, we performed a literature review and meta-analysis to evaluate the effect of green tea supplementation on inflammatory markers [e.g., tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), and interleukin-6 (IL-6)] among patients with MetS and related disorders. We systematically searched for relevant publications up to March 2022 in the PubMed, Scopus, Web of Science, and SciELO databases. The review was registered with PROSPERO (CRD42022320345). Mean differences with 95% confidence intervals were pooled on the basis of the random effects model to compare the effects of green tea with placebo. We used meta-regression and subgroup analyses to determine the cause of heterogeneity and performed study quality assessment using the Grading of Recommendations Assessment, Development, and Evaluation method. We assessed publication bias using funnel plots and Egger’s tests. Out of the total 15 RCTs that were included in this systematic review, 12 were chosen for the meta-analysis. The results revealed that green tea significantly decreased TNF-α levels but did not affect CRP and IL-6 levels. Subgroup analysis showed that green tea supplementation in studies lasting ≤8 weeks significantly increased CRP levels. Furthermore, meta-regression analysis demonstrated a significant association between increasing IL-6 concentration and treatment duration. According to our meta-analysis, green tea was shown to considerably lower circulating TNF-α levels. To confirm these findings, carefully planned trials are required.

Green Tea and Its Relation to Human Gut Microbiome

Type of study: literature review

Number of citations: 74

Year: 2021

Authors: S. Pérez-Burillo, B. Navajas-Porras, Alicia López-Maldonado, D. Hinojosa-Nogueira, S. Pastoriza, J. Rufián‐Henares

Journal: Molecules

Journal ranking: Q1

Key takeaways: Green tea benefits are likely due to beneficial gut bacteria or microbial bioactive metabolites, which influence the development of chronic diseases like obesity and cancer.

Abstract: Green tea can influence the gut microbiota by either stimulating the growth of specific species or by hindering the development of detrimental ones. At the same time, gut bacteria can metabolize green tea compounds and produce smaller bioactive molecules. Accordingly, green tea benefits could be due to beneficial bacteria or to microbial bioactive metabolites. Therefore, the gut microbiota is likely to act as middle man for, at least, some of the green tea benefits on health. Many health promoting effects of green tea seems to be related to the inter-relation between green tea and gut microbiota. Green tea has proven to be able to correct the microbial dysbiosis that appears during several conditions such as obesity or cancer. On the other hand, tea compounds influence the growth of bacterial species involved in inflammatory processes such as the release of LPS or the modulation of IL production; thus, influencing the development of different chronic diseases. There are many studies trying to link either green tea or green tea phenolic compounds to health benefits via gut microbiota. In this review, we tried to summarize the most recent research in the area.

Green tea effects on cognition, mood and human brain function: A systematic review.

Type of study: systematic review

Number of citations: 153

Year: 2017

Authors: E. Mancini, C. Beglinger, J. Drewe, D. Zanchi, U. Lang, S. Borgwardt

Journal: Phytomedicine : international journal of phytotherapy and phytopharmacology

Journal ranking: Q1

Key takeaways: Green tea consumption can reduce anxiety, improve memory and attention, and enhance brain function, with benefits observed under the combined influence of caffeine and l-theanine.

Green Tea Catechins: Nature’s Way of Preventing and Treating Cancer

Type of study:

Number of citations: 107

Year: 2022

Authors: Mohd Farhan

Journal: International Journal of Molecular Sciences

Journal ranking: Q1

Key takeaways: Green tea catechins show potential as lead molecules in the synthesis of novel anticancer drugs and as natural adjuvants to standard chemotherapeutics, potentially preventing and treating various cancers.

Abstract: Green tea’s (Camellia sinensis) anticancer and anti-inflammatory effects are well-known. Catechins are the most effective antioxidants among the physiologically active compounds found in Camellia sinesis. Recent research demonstrates that the number of hydroxyl groups and the presence of specific structural groups have a substantial impact on the antioxidant activity of catechins. Unfermented green tea is the finest source of these chemicals. Catechins have the ability to effectively neutralize reactive oxygen species. The catechin derivatives of green tea include epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG) and epigallocatechin gallate (EGCG). EGCG has the greatest anti-inflammatory and anticancer potential. Notably, catechins in green tea have been explored for their ability to prevent a variety of cancers. Literature evidence, based on epidemiological and laboratory studies, indicates that green tea catechins have certain properties that can serve as the basis for their consideration as lead molecules in the synthesis of novel anticancer drugs and for further exploration of their role as pharmacologically active natural adjuvants to standard chemotherapeutics. The various sections of the article will focus on how catechins affect the survival, proliferation, invasion, angiogenesis, and metastasis of tumors by modulating cellular pathways.

A review on anti-cancer effect of green tea catechins

Type of study: literature review

Number of citations: 122

Year: 2020

Authors: Zhe Cheng, Zhi-fa Zhang, Yu Han, Jing Wang, Yongyong Wang, Xiaoqiang Chen, Shao Yundong, Cheng Yong, Weilong Zhou, Xiao-xuan Lu, Zhengqi Wu

Journal: Journal of Functional Foods

Journal ranking: Q1

Key takeaways: Green tea catechins show anti-cancer properties, suppressing tumor progression, metastasis, and angiogenesis, with potential synergistic effects when combined with other phytochemicals and drugs.

Tea Polyphenols and Their Preventive Measures against Cancer: Current Trends and Directions

Type of study: literature review

Number of citations: 24

Year: 2022

Authors: A. T. Trisha, Mynul Hasan Shakil, Suvro Talukdar, K. Rovina, N. Huda, W. Zzaman

Journal: Foods

Journal ranking: Q1

Key takeaways: Green tea, with its high catechin content, effectively reduces the risk of various cancers, but not lung, esophageal, or stomach cancer.

Abstract: Cancer is exerting an immense strain on the population and health systems all over the world. Green tea because of its higher simple catechin content (up to 30% on dry weight basis) is greatly popular as an anti-cancer agent which is found to reduce the risks of cancer as well as a range of other diseases. In addition, several in vitro and in vivo studies have shown that green tea possesses copious health benefits like anti-diabetic, anti-obese, anti-inflammatory, neuro-protective, cardio-protective, etc. This review highlights the anti-carcinogenic effects of green tea catechins integrating the recent information to gain a clear concept. Special emphasis was given to the effectiveness of green tea polyphenols (GTP) in the prevention of cancer. Overall, green tea has been found to be effective to reduce the risks of breast cancer, ovarian cancer, liver cancer, colorectal cancer, skin cancer, prostate cancer, oral cancer, etc. However, sufficient information was not found to support that green tea consumption reduces the risk of lung cancer, esophageal cancer, or stomach cancer. The exciting data integrated into this article will increase interest in future researchers to garner more fruitful information on the relevant topics.

Two stages of cancer prevention with green tea

Type of study:

Number of citations: 175

Year: 1999

Authors: H. Fujiki

Journal: Journal of Cancer Research and Clinical Oncology

Journal ranking: Q1

Key takeaways: Daily consumption of at least ten cups of green tea can delay cancer onset and reduce recurrence rates in breast cancer patients.

Abstract: Cancer chemoprevention is a new and important medical science in its own right. On the occasion of my presentation entitled “Natural agents and cancer chemoprevention” at the 90th AACR Meeting in 1999, I summarized our recent results on cancer prevention with green tea. In this article, the present status of clinical trials supported by the Chemoprevention Branch of the National Cancer Institute in the United States is first described by way of introduction. Although various natural products are now under investigation in phase I clinical trials, green tea has, perhaps, the greatest potential for further development. In order to expand our understanding of the effects of tea polyphenols and green tea, I review their ability to inhibit growth and cause apoptosis of cancer cells, their distribution into target organs and their other cancer-preventing properties. In addition, the paper focuses on the significance of reducing tumor necrosis factor α (TNFα) gene expression in cells and TNFα release from cells as essential activities for cancer prevention. As for the amounts of green tea effective in cancer prevention, I present two results from our Research Institute: a prospective cohort study with over 8000 individuals in Saitama Prefecture revealed that the daily consumption of at least ten Japanese-size cups of green tea resulted in delayed cancer onset, and a follow-up study of breast cancer patients conducted at our Hospital found that stages I and II breast cancer patients consuming over five cups per day experienced a lower recurrence rate and longer disease-free period than those consuming fewer than four cups per day. Thus, I propose here, for the first time, the two-stage approach to analyzing cancer prevention with green tea: cancer prevention before cancer onset and cancer prevention following cancer treatment. As an additional example of cancer prevention with natural agents, kava, a daily beverage in Fiji, is mentioned. All the evidence reminds us of the significance of alternative medicine in practical cancer prevention.

Cancer Prevention with Green Tea and Its Principal Constituent, EGCG: from Early Investigations to Current Focus on Human Cancer Stem Cells

Type of study: systematic review

Number of citations: 113

Year: 2018

Authors: H. Fujiki, Tatsuro Watanabe, E. Sueoka, Anchalee Rawangkan, M. Suganuma

Journal: Molecules and Cells

Journal ranking: Q1

Key takeaways: Green tea and its main constituent, EGCG, show promising cancer preventive effects, with potential for targeting human cancer stem cells in prevention and treatment.

Abstract: Cancer preventive activities of green tea and its main constituent, (−)-epigallocatechin gallate (EGCG) have been extensively studied by scientists all over the world. Since 1983, we have studied the cancer chemopreventive effects of EGCG as well as green tea extract and underlying molecular mechanisms. The first part of this review summarizes ground-breaking topics with EGCG and green tea extract: 1) Delayed cancer onset as revealed by a 10-year prospective cohort study, 2) Prevention of colorectal adenoma recurrence by a double-blind randomized clinical phase II trial, 3) Inhibition of metastasis of B16 melanoma cells to the lungs of mice, 4) Increase in the average value of Young’s moduli, i.e., cell stiffness, for human lung cancer cell lines and inhibition of cell motility and 5) Synergistic enhancement of anticancer activity against human cancer cell lines with the combination of EGCG and anticancer compounds. In the second part, we became interested in cancer stem cells (CSCs). 1) Cancer stem cells in mouse skin carcinogenesis by way of introduction, after which we discuss two subjects from our review on human CSCs reported by other investigators gathered from a search of PubMed, 2) Expression of stemness markers of human CSCs compared with their parental cells, and 3) EGCG decreases or increases the expression of mRNA and protein in human CSCs. On this point, EGCG inhibited self-renewal and expression of pluripotency-maintaining transcription factors in human CSCs. Human CSCs are thus a target for cancer prevention and treatment with EGCG and green tea catechins.

The role of antioxidant versus pro-oxidant effects of green tea polyphenols in cancer prevention.

Type of study:

Number of citations: 300

Year: 2011

Authors: Sarah C Forester, J. Lambert

Journal: Molecular nutrition & food research

Journal ranking: Q1

Key takeaways: Green tea polyphenols may provide cancer protection, but their role in preventing chronic diseases and their potential pro-oxidant effects require further study.

Abstract: Consumption of green tea (Camellia sinensis) may provide protection against chronic diseases, including cancer. Green tea polyphenols are believed to be responsible for this cancer preventive effect, and the antioxidant activity of the green tea polyphenols has been implicated as a potential mechanism. This hypothesis has been difficult to study in vivo due to metabolism of these compounds and poor understanding of the redox environment in vivo. Green tea polyphenols can be direct antioxidants by scavenging reactive oxygen species or chelating transition metals as has been demonstrated in vitro. Alternatively, they may act indirectly by upregulating phase II antioxidant enzymes. Evidence of this latter effect has been observed in vivo, yet more work is required to determine under which conditions these mechanisms occur. Green tea polyphenols can also be potent pro-oxidants, both in vitro and in vivo, leading to the formation of hydrogen peroxide, the hydroxyl radical, and superoxide anion. The potential role of these pro-oxidant effects in the cancer preventive activity of green tea is not well understood. The evidence for not only the antioxidant, but also pro-oxidant, properties of green tea is discussed in the present review.

Why drinking green tea could prevent cancer

Type of study:

Number of citations: 717

Year: 1997

Authors: J. Jankun, S. Selman, R. Świercz, E. Skrzypczak‐Jankun

Journal: Nature

Journal ranking: Q1

Key takeaways: Drinking green tea may help prevent cancers, as it inhibits urokinase, a crucial enzyme crucial for cancer growth.

Challenging the effectiveness of green tea in primary and tertiary cancer prevention

Type of study: literature review

Number of citations: 42

Year: 2012

Authors: H. Fujiki, K. Imai, K. Nakachi, M. Shimizu, H. Moriwaki, M. Suganuma

Journal: Journal of Cancer Research and Clinical Oncology

Journal ranking: Q1

Key takeaways: Drinking 10 Japanese-size cups of green tea per day significantly delays cancer onset and prevents colorectal adenomas recurrence in patients.

Abstract: PurposeDrinking green tea daily is part of Japanese culture, and various studies have revealed that green tea is a cancer preventive. We here review our progress in cancer prevention with green tea on 12 main topics, from basic to clinical level.Topics and methodsBiochemical and biological studies of green tea catechins, a prospective cohort study, preclinical safety trials with tablets of green tea extract, double-blind randomized clinical phase II prevention trial for recurrence of colorectal adenomas, and synergistically enhanced inhibition by the combination of green tea catechins and anticancer drugs. All results were significant, including human studies with informed consent.ResultsDrinking 10 Japanese-size cups of green tea per day delayed the cancer onset of humans 7 years for females. For tertiary cancer prevention, consuming 10 cups of green tea per day fortified by green tea tablets, 50 %, significantly prevented the recurrence of colorectal adenomas. A minimum effective amount of green tea catechins for cancer prevention was found in humans. In addition, the combination of green tea catechins and anticancer drugs engendered a new cancer therapeutic strategy.ConclusionThe consumption of 10 Japanese-size cups of green tea per day is a significant factor in primary cancer prevention for the general population, and the preventive effect on recurrence of colorectal adenomas in patients is vital evidence in tertiary cancer prevention.

Green tea (Camellia sinensis) for the prevention of cancer.

Type of study: systematic review

Number of citations: 14

Year: 2020

Authors: T. Filippini, M. Malavolti, F. Borrelli, A. Izzo, S. Fairweather-Tait, M. Horneber, M. Vinceti

Journal: The Cochrane database of systematic reviews

Journal ranking: Q1

Key takeaways: Green tea consumption may reduce the risk of prostate and gynecological cancers, but its effect on non-melanoma skin cancer remains unclear.

Abstract: BACKGROUND This review is an update of a previously published review in the Cochrane Database of Systematic Reviews (2009, Issue 3).Tea is one of the most commonly consumed beverages worldwide. Teas from the plant Camellia sinensis can be grouped into green, black and oolong tea, and drinking habits vary cross-culturally. C sinensis contains polyphenols, one subgroup being catechins. Catechins are powerful antioxidants, and laboratory studies have suggested that these compounds may inhibit cancer cell proliferation. Some experimental and nonexperimental epidemiological studies have suggested that green tea may have cancer-preventative effects. OBJECTIVES To assess possible associations between green tea consumption and the risk of cancer incidence and mortality as primary outcomes, and safety data and quality of life as secondary outcomes. SEARCH METHODS We searched eligible studies up to January 2019 in CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and reference lists of previous reviews and included studies. SELECTION CRITERIA We included all epidemiological studies, experimental (i.e. randomised controlled trials (RCTs)) and nonexperimental (non-randomised studies, i.e. observational studies with both cohort and case-control design) that investigated the association of green tea consumption with cancer risk or quality of life, or both. DATA COLLECTION AND ANALYSIS Two or more review authors independently applied the study criteria, extracted data and assessed methodological quality of studies. We summarised the results according to diagnosis of cancer type. MAIN RESULTS In this review update, we included in total 142 completed studies (11 experimental and 131 nonexperimental) and two ongoing studies. This is an additional 10 experimental and 85 nonexperimental studies from those included in the previous version of the review. Eleven experimental studies allocated a total of 1795 participants to either green tea extract or placebo, all demonstrating an overall high methodological quality based on 'Risk of bias' assessment. For incident prostate cancer, the summary risk ratio (RR) in the green tea-supplemented participants was 0.50 (95% confidence interval (CI) 0.18 to 1.36), based on three studies and involving 201 participants (low-certainty evidence). The summary RR for gynaecological cancer was 1.50 (95% CI 0.41 to 5.48; 2 studies, 1157 participants; low-certainty evidence). No evidence of effect of non-melanoma skin cancer emerged (summary RR 1.00, 95% CI 0.06 to 15.92; 1 study, 1075 participants; low-certainty evidence). In addition, adverse effects of green tea extract intake were reported, including gastrointestinal disorders, elevation of liver enzymes, and, more rarely, insomnia, raised blood pressure and skin/subcutaneous reactions. Consumption of green tea extracts induced a slight improvement in quality of life, compared with placebo, based on three experimental studies. In nonexperimental studies, we included over 1,100,000 participants from 46 cohort studies and 85 case-control studies, which were on average of intermediate to high methodological quality based on Newcastle-Ottawa Scale 'Risk of bias' assessment. When comparing the highest intake of green tea with the lowest, we found a lower overall cancer incidence (summary RR 0.83, 95% CI 0.65 to 1.07), based on three studies, involving 52,479 participants (low-certainty evidence). Conversely, we found no association between green tea consumption and cancer-related mortality (summary RR 0.99, 95% CI 0.91 to 1.07), based on eight studies and 504,366 participants (low-certainty evidence). For most of the site-specific cancers we observed a decreased RR in the highest category of green tea consumption compared with the lowest one. After stratifying the analysis according to study design, we found strongly conflicting results for some cancer sites: oesophageal, prostate and urinary tract cancer, and leukaemia showed an increased RR in cohort studies and a decreased RR or no difference in case-control studies. AUTHORS' CONCLUSIONS Overall, findings from experimental and nonexperimental epidemiological studies yielded inconsistent results, thus providing limited evidence for the beneficial effect of green tea consumption on the overall risk of cancer or on specific cancer sites. Some evidence of a beneficial effect of green tea at some cancer sites emerged from the RCTs and from case-control studies, but their methodological limitations, such as the low number and size of the studies, and the inconsistencies with the results of cohort studies, limit the interpretability of the RR estimates. The studies also indicated the occurrence of several side effects associated with high intakes of green tea. In addition, the majority of included studies were carried out in Asian populations characterised by a high intake of green tea, thus limiting the generalisability of the findings to other populations. Well conducted and adequately powered RCTs would be needed to draw conclusions on the possible beneficial effects of green tea consumption on cancer risk.

Green Tea and Cancer Prevention

Type of study:

Number of citations: 180

Year: 2010

Authors: Chung S. Yang, Xin Wang

Journal: Nutrition and Cancer

Journal ranking: Q2

Key takeaways: Green tea polyphenols show potential in preventing various types of cancer by suppressing cell proliferation, promoting apoptosis, and inhibiting cell invasion, angiogenesis, and metastasis.

Abstract: Extracts of green tea and green tea polyphenols have exhibited inhibitory effects against the formation and development of tumors at different organ sites in animals. These include animal models for skin, lung, oral cavity, esophagus, stomach, intestine, colon, liver, pancreas, bladder, mammary gland, and prostate cancers. In addition to suppressing cell proliferation, promoting apoptosis, and modulating signaling transduction, green tea polyphenols, especially (-)-epigallocatechin-3-gallate, also inhibit cell invasion, angiogenesis, and metastasis. This article reviews data on the cancer preventive activities of green tea polyphenols, possible mechanisms involved, and the relationship between green tea consumption and human cancer risk.

Possible Mechanisms of Green Tea and Its Constituents against Cancer

Type of study: literature review

Number of citations: 115

Year: 2018

Authors: Y. Shirakami, M. Shimizu

Journal: Molecules : A Journal of Synthetic Chemistry and Natural Product Chemistry

Journal ranking: Q1

Key takeaways: Green tea has anti-cancer activity through diverse mechanisms, including anti-oxidant activity, cell cycle regulation, receptor tyrosine kinase pathway inhibition, immune system modulation, and epigenetic modification control.

Abstract: A number of epidemiological, clinical, and experimental researches have indicated that administration of green tea appears to have anti-cancer activity. According to findings of laboratory cell culture studies, a diverse mechanism has been observed underlying the effects of green tea catechins against cancer. These mechanisms include anti-oxidant activity, cell cycle regulation, receptor tyrosine kinase pathway inhibition, immune system modulation, and epigenetic modification control. This review discusses the results of these studies to provide more insight into the effects of green tea administration on cancers observed to date in this research field.

Anti-Cancer Effects of Green Tea Polyphenols Against Prostate Cancer

Type of study: literature review

Number of citations: 104

Year: 2019

Authors: Y. Miyata, Y. Shida, T. Hakariya, H. Sakai

Journal: Molecules

Journal ranking: Q1

Key takeaways: Green tea polyphenols show potential in preventing and treating prostate cancer, with molecular mechanisms influencing tumor growth, apoptosis, and androgen receptor signaling.

Abstract: Prostate cancer is the most common cancer among men. Green tea consumption is reported to play an important role in the prevention of carcinogenesis in many types of malignancies, including prostate cancer; however, epidemiological studies show conflicting results regarding these anti-cancer effects. In recent years, in addition to prevention, many investigators have shown the efficacy and safety of green tea polyphenols and combination therapies with green tea extracts and anti-cancer agents in in vivo and in vitro studies. Furthermore, numerous studies have revealed the molecular mechanisms of the anti-cancer effects of green tea extracts. We believe that improved understanding of the detailed pathological roles at the molecular level is important to evaluate the prevention and treatment of prostate cancer. Therefore, in this review, we present current knowledge regarding the anti-cancer effects of green tea extracts in the prevention and treatment of prostate cancer, with a particular focus on the molecular mechanisms of action, such as influencing tumor growth, apoptosis, androgen receptor signaling, cell cycle, and various malignant behaviors. Finally, the future direction for the use of green tea extracts as treatment strategies in patients with prostate cancer is introduced.

The antioxidant and pro-oxidant activities of green tea polyphenols: a role in cancer prevention.

Type of study: literature review

Number of citations: 817

Year: 2010

Authors: J. Lambert, R. Elias

Journal: Archives of biochemistry and biophysics

Journal ranking: Q1

Key takeaways: Green tea polyphenols, particularly EGCG, may inhibit cancer progression by inducing apoptosis in tumor cells and inducing endogenous antioxidant systems in normal tissues.

Cancer-preventive effects of drinking green tea among a Japanese population.

Type of study: non-rct observational study

Number of citations: 374

Year: 1997

Authors: K. Imai, K. Suga, K. Nakachi

Journal: Preventive medicine

Journal ranking: Q1

Key takeaways: Drinking green tea has a potentially preventive effect against cancer, especially among females who consume more than 10 cups a day.

Abstract: BACKGROUND Laboratory studies have revealed the cancer preventive effects of green tea, so the association between green tea consumption and cancer was examined in a human population. METHODS The association between green tea consumption and cancer incidence was studied in our prospective cohort study of a Japanese population. We surveyed 8,552 individuals over 40 years of age living in a town in Saitama prefecture on their living habits, including daily consumption of green tea. During the 9 years of follow-up study (71,248.5 person-years), we identified a total of 384 cases of cancer in all sites. RESULTS We found a negative association between green tea consumption and cancer incidence, especially among females drinking more than 10 cups a day. The slowdown in increase of cancer incidence with age observed among females who consumed more than 10 cups a day is consistent with the finding that increased consumption of green tea is associated with later onset of cancer. Age-standardized average annual incidence rate was significantly lower among females who consumed large amounts of green tea. Relative risk (RR) of cancer incidence was also lower among both females (RR = 0.57, 95% CI = 0.33-0.98) and males (RR = 0.68, 95% CI = 0.39-1.21) in groups with the highest consumption, although the preventive effects did not achieve statistical significance among males, even when stratified by smoking and adjusted for alcohol and dietary variables. CONCLUSION Our epidemiological study showed that green tea has a potentially preventive effect against cancer among humans.

Cancer prevention by green tea: evidence from epidemiologic studies.

Type of study:

Number of citations: 118

Year: 2013

Authors: Jian-Min Yuan

Journal: The American journal of clinical nutrition

Journal ranking: Q1

Key takeaways: Green tea intake may have a protective role in oral-digestive tract cancer, but current data on liver cancer, lung cancer, and prostate cancer development is mixed.

Abstract: In contrast to the consistent results of an inhibitory effect of green tea extracts and tea polyphenols on the development and growth of carcinogen-induced tumors in experimental animal models, results from human studies are mixed. Both observational and intervention studies have provided evidence in support of a protective role of green tea intake in the development of oral-digestive tract cancer or an inhibitory role of oral supplementation of green tea extract on a precancerous lesion of oral cavity. Evidence in support of green tea intake against the development of liver cancer risk is limited and inconsistent. An inverse association between green tea intake and lung cancer risk has been observed among never smokers but not among smokers. Although observational studies do not support a beneficial role of tea intake against the development of prostate cancer, several phase 2 clinical trials have shown an inhibitory effect of green tea extract against the progression of prostate premalignant lesions to malignant tumors. Prospective epidemiologic studies so far have not provided evidence for a protective effect of green tea consumption on breast cancer development. Current data neither confirm nor refute a definitive cancer-preventive role of green tea intake. Large randomized intervention trials on the efficacy of green tea polyphenols or extracts are required before a recommendation for green tea consumption for cancer prevention should be made.

Green tea: Health benefits as cancer preventive for humans.

Type of study: literature review

Number of citations: 110

Year: 2005

Authors: H. Fujiki

Journal: Chemical record

Journal ranking: Q1

Key takeaways: Green tea consumption, particularly 10 Japanese-size cups per day, may delay cancer onset and prevent cancer recurrence.

Abstract: Green tea is an acknowledged cancer preventive in Japan. The aim of this review article is to develop the concept of cancer prevention with green tea beverage for humans, which has largely been our exclusive research territory. This paper briefly reviews several topics, beginning with the introduction of our initial work on penta-O-galloyl-beta-D-glucose and (-)-epigallocatechin gallate (EGCG), the main constituent of green tea extract. The mechanisms of EGCG action, particularly the reduction of TNF-alpha are discussed, and we show how use of 3H-EGCG revealed a wide range of target organs for cancer prevention. The results of an epidemiological study in Saitama Prefecture allowed us to determine the cancer preventive amount of green tea-10 Japanese-size cups per day, about 2.5 g green tea extract-which made it possible for us to introduce the two-stage strategy of cancer prevention with green tea. The first stage is the delay of cancer onset for the general population. The second stage is the prevention of recurrence of cancer for patients following cancer treatment. Combination cancer prevention with green tea and cancer preventive drugs is proving especially beneficial for Japanese, who drink green tea every day. And finally, the stimulating comments of Prof. Jim Watson have encouraged green tea scientists.

Green Tea in Reproductive Cancers: Could Treatment Be as Simple?

Type of study: systematic review

Number of citations: 21

Year: 2023

Authors: Maclaine A Parish, Gaelle Massoud, Dana Hazimeh, J. Segars, M. Islam

Journal: Cancers

Journal ranking: Q1

Key takeaways: Green tea, specifically its component EGCG, shows potential benefits in treating reproductive cancers, potentially offering new therapeutic strategies for female reproductive cancer management.

Abstract: Simple Summary Green tea is a popular beverage worldwide and has shown to be beneficial in the treatment of different cancers. However, its role in the treatment of reproductive cancers remains controversial. This review aims to summarize the data available in the literature about the role of green tea in treating gynecological cancers. Examination of available evidence may provide a better understanding of the green tea benefits and focus future research related to this topic. Abstract Green tea originates from the tea plant Camellia sinensis and is one of the most widely consumed beverages worldwide. Green tea polyphenols, commonly known as catechins, are the major bioactive ingredients and account for green tea’s unique health benefits. Epigallocatechin-3-gallate (EGCG), is the most potent catechin derivative and has been widely studied for its pro- and anti-oxidative effects. This review summarizes the chemical and chemopreventive properties of green tea in the context of female reproductive cancers. A comprehensive search of PubMed and Google Scholar up to December 2022 was conducted. All original and review articles related to green tea or EGCG, and gynecological cancers published in English were included. The findings of several in vitro, in vivo, and epidemiological studies examining the effect of green tea on reproductive cancers, including ovarian, cervical, endometrial, and vulvar cancers, are presented. Studies have shown that this compound targets specific receptors and intracellular signaling pathways involved in cancer pathogenesis. The potential benefits of using green tea in the treatment of reproductive cancers, alone or in conjunction with chemotherapeutic agents, are examined, shedding light on new therapeutic strategies for the management of female reproductive cancers.