Research Database
The only comprehensive database for clinical and medical research papers on the healthy benefits of matcha/green tea.
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Cognitive Function
Matcha consumption leads to much higher intake of green tea phytochemicals compared to regular green tea. Previous research on caffeine, L-theanine, and epigallocatechin gallate (EGCG) repeatedly demonstrated benefits on cognitive performance.
Learn MoreHeart Health
According to Harvard Medical School, “lowering your risk of cardiovascular disease may be as easy as drinking green tea. Studies suggest this light, aromatic tea may lower LDL cholesterol and triglycerides, which may be responsible for the tea's association with reduced risk of death from heart disease and stroke.”
Learn MoreMental Health
Matcha contains an amino acid called L-theanine, which has been shown to reduce physiological and psychological stresses. L-theanine also improves cognition and mood in a synergistic manner with caffeine, and promotes alpha wave production in the brain
Learn MoreCancer Prevention
Matcha/green tea has for many centuries been regarded as an essential part of good health in Japan and China. Many believe it can help reduce the risk of cancer, and a growing body of evidence backs this up.
Learn MoreImmunity
A recent study in the journal Proceedings of the National Academy of Sciences concluded that drinking matcha daily greatly enhanced the overall response of the immune system. The exceedingly high levels of antioxidants in matcha mainly take the form of polyphenols, catechins, and flavonoids, each of which aids the body’s defense in its daily struggles against free radicals that come from the pollution in your air, water and foods.
Learn MoreMost Recent Research Articles
Author: Laura Baselga-Escudero, Cinta Blade, Aleix Ribas-Latre, Ester Casanova, Manuel Suárez, Josep Lluís Torres, M. Josepa Salvadó, Lluis Arola and Anna Arola-Arnal
Modulation of miR-33 and miR-122 has been proposed to be a promising strategy to treat dyslipidemia and insulin resistance associated with obesity and metabolic syndrome. Interestingly, specific polyphenols reduce the levels of these mi(cro)RNAs. The aim of this study was to elucidate the effect of polyphenols of different chemical structure on miR-33a and miR-122 expression and to determine whether direct binding of the polyphenol to the mature microRNAs (miRNAs) is a plausible mechanism of modulation. The effect of two grape proanthocyanidin extracts, their fractions and pure polyphenol compounds on miRNA expression was evaluated using hepatic cell lines. Results demonstrated that the effect on miRNA expression depended on the polyphenol chemical structure. Moreover, miR-33a was repressed independently of its host-gene SREBP2. Therefore, the ability of resveratrol and epigallocatechin gallate to bind miR-33a and miR-122 was measured using 1H NMR spectroscopy. Both compounds bound miR-33a and miR-122 and differently. Interestingly, the nature of the binding of these compounds to the miRNAs was consistent with their effects on cell miRNA levels. Therefore, the specific and direct binding of polyphenols to miRNAs emerges as a new posttranscriptional mechanism by which polyphenols could modulate metabolism.
Author: David A Camfield , Con Stough , Jonathon Farrimond , Andrew B Scholey
A systematic review and meta-analysis was conducted on 11 randomized placebo-controlled human studies of acute effects of tea constituents L-theanine and epigallocatechin gallate, administered alone or in combination with caffeine, on cognitive function and mood. The outcome measures of mood were alertness, calmness, and contentedness, derived from the Bond-Lader scales, and state anxiety, from the State-Trait Anxiety Inventory. Cognitive measures assessed were attentional switch, intersensory attention, and rapid visual information processing. Standardized mean differences between placebo and treatment groups are presented for each study and outcome measure. Meta-analysis using a random-effects model was conducted when data were available for three or more studies. Evidence of moderate effect sizes in favor of combined caffeine and L-theanine in the first 2 hours postdose were found for outcome measures Bond-Lader alertness, attentional switching accuracy, and, to a lesser extent, some unisensory and multisensory attentional outcomes. Moderator analysis of caffeine and L-theanine doses revealed trends toward greater change in effect size for caffeine dose than for L-theanine dose, particularly during the first hour postdose.
Author: David O. Kennedy
Flavonoids and other polyphenols are ubiquitous plant chemicals that fulfill a range of ecologic roles for their home plant, including protection from a range of biotic and abiotic stressors and a pivotal role in the management of pathogenic and symbiotic soil bacteria and fungi. They form a natural part of the human diet, and evidence suggests that their consumption is associated with the beneficial modulation of a number of health-related variables, including those related to cardiovascular and brain function. Over recent years, the consensus as to the mechanisms responsible for these effects in humans has shifted away from polyphenols having direct antioxidant effects and toward their modulation of cellular signal transduction pathways. To date, little consideration has been given to the question of why, rather than how, these plant-derived chemicals might exert these effects. Therefore, this review summarizes the evidence suggesting that polyphenols beneficially affect human brain function and describes the current mechanistic hypotheses explaining these effects. It then goes on to describe the ecologic roles and potential endogenous signaling functions that these ubiquitous phytochemicals play within their home plant and discusses whether these functions drive their beneficial effects in humans via a process of “cross-kingdom” signaling predicated on the many conserved similarities in plant, microbial, and human cellular signal transduction pathways.
Author: Bhaskar Kahali, Stefanie B. Marquez, Kenneth W. Thompson, Jinlong Yu, Sarah J.B. Gramling, Li Lu, Aaron Aponick and David Reisman
Flavonoids have been extensively studied and are well documented to have anticancer effects, but it is not entirely known how they impact cellular mechanisms to elicit these effects. In the course of this study, we found that a variety of different flavonoids readily restored Brahma (BRM) in BRM-deficient cancer cell lines. Flavonoids from each of the six different structural groups were effective at inducing BRM expression as well as inhibiting growth in these BRM-deficient cancer cells. By blocking the induction of BRM with shRNA, we found that flavonoid-induced growth inhibition was BRM dependent. We also found that flavonoids can restore BRM functionality by reversing BRM acetylation. In addition, we observed that an array of natural flavonoid-containing products both induced BRM expression as well as deacetylated the BRM protein. We also tested two of the BRM-inducing flavonoids (Rutin and Diosmin) at both a low and a high dose on the development of tumors in an established murine lung cancer model. We found that these flavonoids effectively blocked development of adenomas in the lungs of wild-type mice but not in that of BRMnull mice. These data demonstrate that BRM expression and function are regulated by flavonoids and that functional BRM appears to be a prerequisite for the anticancer effects of flavonoids both in vitro and in vivo.
Author: Yi-wei Lin, Zheng-hui Hu, Xiao Wang, Qi-qi Mao, Jie Qin, Xiang-yi Zheng, Li-ping Xie
Objectives Tea is supposed to have chemopreventive effect against various cancers. However, the protective role of tea in prostate cancer is still controversial. The aim of this study is to elucidate the association between tea consumption and prostate cancer risk by meta-analysis. Methods A total of 21 published articles were retrieved via both computerized searches and review of references. Estimates of OR/RR for highest versus non/lowest tea consumption levels were pooled on the basis of random effect model or fixed effect model as appropriate. Stratified analyses on tea type, population and study design were also conducted. Results No statistical significance was detected between tea consumption and prostate cancer risk in meta-analysis of all included studies (odds ratio (OR) = 0.86, 95% CI (0.69-1.04)). Furthermore, stratified analyses on population (Asian, OR = 0.81, 95% CI (0.55-1.08); non-Asian, OR = 0.89, 95% CI (0.72-1.07)) and tea type (green tea, OR = 0.79, 95% CI (0.43-1.14); black tea, OR = 0.88, 95% CI (0.73-1.02)) also yielded non-significant association. Only the case–control study subgroup demonstrated a borderline protective effect for tea consumption against prostate cancer (OR = 0.77, 95% CI (0.55-0.98)). Conclusion Our analyses did not support the conclusion that tea consumption could reduce prostate cancer risk. Further epidemiology studies are needed.
Author: James Yarmolinsky , Giorgia Gon , Phil Edwards
Context: Tea has been proposed as an antihypertensive agent for individuals with elevated blood pressure, yet the evidence for this has not been systematically reviewed to date. Objective: The aim of this review was to evaluate the effects of tea on blood pressure in individuals within the prehypertensive and hypertensive blood pressure ranges. Data Sources: The CENTRAL, PubMed, Embase, and Web of Science databases were searched for all relevant studies published from 1946 to September 27, 2013. Study Selection: The selection criteria included randomized controlled trials of adults whose blood pressure was within hypertensive or prehypertensive ranges and in which the applied intervention was green or black tea; controls consisting of placebo, minimal tea intervention, or no intervention; and a follow-up period of at least 2 months. Data Extraction: Two reviewers independently extracted data on participants, interventions, comparators, outcomes, and study design. Mean differences (MDs) and 95% confidence intervals (95%CIs) were pooled to generate summary effect estimates. Results: Meta-analyses of 10 trials (834 participants) showed statistically significant reductions in systolic blood pressure (MD −2.36 mmHg, 95%CI −4.20 to −0.52) and diastolic blood pressure (MD −1.77 mmHg, 95%CI −3.03 to −0.52) with tea consumption. Conclusions: Consumption of green or black tea can reduce blood pressure in individuals within prehypertensive and hypertensive ranges, although further investigation with studies of longer duration and stronger methodological quality is warranted to confirm these findings.
Author: Yanqiu Wang and Bowen Wang and Feng Du and Xuesong Su and Guangping Sun and Guangyu Zhou and Xiaohui Bian and Na Liu
The severity of tubulointerstitial fibrosis is regarded as an important determinant of renal prognosis. Therapeutic strategies targeting tubulointerstitial fibrosis have been considered to have potential in the treatment of chronic kidney disease. This study aims to evaluate the protective effects of (-)-epigallocatechin-3-gallate (EGCG), a green tea polyphenol, against renal interstitial fibrosis in mice. EGCG was administrated intraperitoneally for 14 days in a mouse model of unilateral ureteral obstruction (UUO). The results of our histological examination showed that EGCG alleviated glomerular and tubular injury and attenuated renal interstitial fibrosis in UUO mice. Furthermore, the inflammatory responses induced by UUO were inhibited, as represented by decreased macrophage infiltration and inflammatory cytokine production. Additionally, the expression of type I and III collagen in the kidney were reduced by EGCG, which indicated an inhibition of extracellular matrix accumulation. EGCG also caused an up-regulation in α-smooth muscle actin expression and a down-regulation in E-cadherin expression, indicating the inhibition of epithelial-to-mesenchymal transition. These changes were found to be in parallel with the decreased level of TGF-β1 and phosphorylated Smad. In conclusion, the present study demonstrates that EGCG could attenuate renal interstitial fibrosis in UUO mice, and this renoprotective effect might be associated with its effects of inflammatory responses alleviation and TGF-β/Smad signaling pathway inhibition.
Author: Yi Zeng and Huashuai Chen and Ting Ni and Rongping Ruan and Lei Feng and Chao Nie and Lingguo Cheng and Yang Li and Wei Tao and Jun Gu and Kenneth C. Land and Anatoli Yashin and Qihua Tan and Ze Yang and Lars Bolund and Huanming Yang and Elizabeth Hauser and D. Craig Willcox and Bradley J. Willcox and Xiao-Li Tian and James W. Vaupel
Logistic regression analysis based on data from 822 Han Chinese oldest old aged 92+ demonstrated that interactions between carrying FOXO1A-266 or FOXO3-310 or FOXO3-292 and tea drinking at around age 60 or at present time were significantly associated with lower risk of cognitive disability at advanced ages. Associations between tea drinking and reduced cognitive disability were much stronger among carriers of the genotypes of FOXO1A-266 or FOXO3-310 or FOXO3-292 compared with noncarriers, and it was reconfirmed by analysis of three-way interactions across FOXO genotypes, tea drinking at around age 60, and at present time. Based on prior findings from animal and human cell models, we postulate that intake of tea compounds may activate FOXO gene expression, which in turn may positively affect cognitive function in the oldest old population. Our empirical findings imply that the health benefits of particular nutritional interventions, including tea drinking, may, in part, depend upon individual genetic profiles.
Author: Xiaoxin Dong and Chen Yang and Shiyi Cao and Yong Gan and Huilian Sun and Yanhong Gong and Huajie Yang and Xiaoxu Yin and Zuxun Lu
OBJECTIVE: Whether tea consumption decreases the risk of depression remains controversial. We performed a meta-analysis of findings from observational studies to evaluate the association between tea consumption and depression risk. METHOD: Embase, PubMed, and Chinese National Knowledge Infrastructure databases were searched from their inception through August 2014 for observational studies that had reported the association between tea consumption and depression risk. We used a fixed effects model when heterogeneity was negligible and a random effect model when heterogeneity was significant to calculate the summary relative risk estimates (RRs) and 95% confidence intervals (CIs). RESULTS: Eleven studies with 13 reports were eligible for inclusion in the meta-analysis (22,817 participants with 4,743 cases of depression). Compared to individuals with lower tea consumption, those with higher tea consumption had a pooled RR of depression risk at 0.69 (95% CI: 0.63-0.75). Eight reports were included in the dose-response analysis of tea consumption and depression risk (10,600 participants with 2,107 cases). There was a linear association between tea consumption and the risk of depression, with an increment of 3 cups/day in tea consumption associated with a decrease in the risk of depression of 37% (RR = 0.63, 95% CI: 0.55-0.71). CONCLUSION: Tea consumption is associated with a decreased risk of depression.
Author: Mako Kurogi and Yasushi Kawai and Katsuhiro Nagatomo and Michihiro Tateyama and Yoshihiro Kubo and Osamu Saitoh
The sensation of astringency is elicited by catechins and their polymers in wine and tea. It has been considered that catechins in green tea are unstable and auto-oxidized to induce more astringent taste. Here, we examined how mammalian transient receptor potential V1 (TRPV1) and TRPA1, which are nociceptive sensors, are activated by green tea catechins during the auto-oxidation process. Neither TRPV1 nor TRPA1 could be activated by any of the freshly prepared catechin. When one of the major catechin, epigallocatechin gallate (EGCG), was preincubated for 3h in Hank's balanced salt solution, it significantly activated both TRP channels expressed in HEK293 cells. Even after incubation, other catechins showed much less effects. Results suggest that only oxidative products of EGCG activate both TRPV1 and TRPA1. Dorsal root ganglion (DRG) sensory neurons were also activated by the incubated EGCG through TRPV1 and TRPA1 channels. Liquid chromatography-mass spectrometry revealed that theasinensins A and D are formed during incubation of EGCG. We found that purified theasinensin A activates both TRPV1 and TRPA1, and that it stimulates DRG neurons through TRPV1 and TRPA1 channels. Results suggested a possibility that TRPV1 and TRPA1 channels are involved in the sense of astringent taste of green tea.