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: Ilze Vermaak and Alvaro M. Viljoen and Josias H. Hamman and Sandy F. Van Vuuren
Few in vitro screening studies on the biological activities of plant extracts that are intended for oral administration consider the effect of the gastrointestinal system. This study investigated this aspect on extracts of Camellia sinensis (green tea) and Salvia officinalis (sage) using antimicrobial activity as a model for demonstration. Both the crude extracts and their products after exposure to simulated gastric fluid (SGF) as well as simulated intestinal fluid (SIF) were screened for antimicrobial activity. The chromatographic profiles of the crude plant extracts and their SGF as well as SIF products were recorded and compared qualitatively by means of high performance liquid chromatography coupled to mass spectrometry. The effect of epithelial transport on the crude plant extracts was determined by applying them to an in vitro intestinal epithelial model (Caco-2). The crude extracts for both plants exhibited reduced antimicrobial activity after exposure to SGF, while no antimicrobial activity was detected after exposure to SIF. These results suggested chemical modification or degradation of the antimicrobial compounds when exposed to gastrointestinal conditions. This was confirmed by a reduction of the peak areas on the LC–UV–MS chromatograms. From the chromatographic profiles obtained during the transport study, it is evident that some compounds in the crude plant extracts were either not transported across the cell monolayer or they were metabolised during passage through the cells. It can be deduced that the gastrointestinal environment and epithelial transport process can dramatically affect the chromatographic profiles and biological activity of orally ingested natural products.
Author: Ziyin Yang and Tomomi Kinoshita and Aya Tanida and Hironori Sayama and Akio Morita and Naoharu Watanabe
Coumarin is a natural product well-known for its pleasant sweet-herbaceous and cherry flower-like odour. Despite coumarin being widely found in the plant kingdom, its occurrence in tea leaves is very poorly characterised. In this work, green tea made from the cultivars “Shizu-7132”, “Koushun” and “Tsuyuhikari” were found to have sweet-herbaceous odour. Application of the stable isotope dilution assay for the quantification of coumarin revealed that its levels in these Japanese green tea products ranged from 0.26 to 0.88 μg/g of green tea product, whereas concentrations were generally below 0.2 μg/g in common green tea products. In contrast to the leaf, the stem part contained much less coumarin. During the manufacturing process of the tea (Shizu-7132), the steaming time and drying temperature influenced the content of coumarin in the final product. Due to hydrolysis of glycosidically bound coumarin precursors, in fresh tea leaves most coumarin occurred in its free form. Tea leaves also contained small amounts of bound coumarin precursors, such as primeveroside.
Author: Ana Carolina Magalhães and Annette Wiegand and Daniela Rios and Angélica Hannas and Thomas Attin and Marília Afonso Rabelo Buzalaf
Objectives This in situ/ex vivo study aimed to analyse the impact of possible MMP-inhibitors (chlorhexidine and green tea extract) on dentin wear induced by erosion or erosion plus abrasion. Methods Twelve volunteers took part in this cross-over and double-blind study performed in 4 phases of each 5 days. Bovine dentin samples were worn in palatal appliances and subjected to extraoral erosion (4 times/day, Coca-Cola, 5 min) or erosion plus abrasion (2 times/day, fluoride-free toothpaste and electrical toothbrush, 15 s/sample). Immediately after each erosion, the appliances were reinserted in the mouth and the oral cavity was rinsed for 60 s with: 250 ppm F solution (SnF2/AmF, pH 4.5, Meridol-Gaba, Switzerland), 0.12% chlorhexidine digluconate (0.06% chlorhexidine, pH 6.0, Periogard-Colgate, Brazil), 0.61% green tea extract solution (OM24®, 100% Camellia Sinensis leaf extract, catechin concentration: 30 ± 3%, pH 7.0, Omnimedica, Switzerland) or deionized water (pH 6.0, control). Dentin loss was assessed by profilometry (μm). The data were analysed by two-way repeated measures ANOVA and Bonferroni post hoc test. Results There was a significant difference between the conditions (Ero × Ero + Abr, p < 0.001) and among the solutions (p < 0.001). All solutions (F: 1.42 ± 0.34; 1.73 ± 0.50, chlorhexidine: 1.15 ± 0.26; 1.59 ± 0.32, green tea: 1.06 ± 0.30; 1.54 ± 0.55) significantly reduced the dentin wear when compared to control (2.00 ± 0.55; 2.41 ± 0.83) for both conditions. There were not significant differences among green tea extract, chlorhexidine and F solutions. Conclusions Thus, the possible MMP-inhibitors tested in this study seem to be a promising preventive measure to reduce dentin erosion-abrasion, but their mechanism of action needs to be investigated in further studies.
Author: Qihua Gu and Chengping Hu and Qiong Chen and Ying Xia and Juntao Feng and Hongzhong Yang
Background A convenient animal model of primary lung cancer is compelling for investigation into the disease mechanisms and for development of therapeutic strategies. This study aims to develop a reproducible rat model for lung carcinoma by intra-pulmonary injection of 3,4-benzopyrene, and to evaluate the preventive effect of green tea on the formation of lung carcinoma. MethodsSprague–Dawley rats of the same ages were randomly assigned into three groups treated differently. Rats in group one were given green tea in drinking water (tea concentration: 1.2%; tea polyphenols in the tea solution: 0.3%); rats in the groups two and three were given blank drinking water. Rats in the groups one and two were injected intra-pulmonarily with 3,4-benzopyrene dissolved in corn oil (2 mg/0.2 mL/injection, fortnightly, 4 times in all); rats in the group three were injected with the vehicle corn oil as the control for injection. All the rats were sacrificed one year after the first intra-pulmonary injection. Tumors developed in rats and lung tissues were collected for carcinoma diagnosis and for p53 and bcl-2 expression. Results Intra-pulmonary injection of 3,4-benzopyrene steady induced lung carcinoma at a success rate of 75%. Administration with green tea drinking significantly reduced the incidence of lung carcinoma to 30%. Green tea up-regulated p53 expression in lung carcinoma, but significantly down-regulated bcl-2 expression. Conclusions Intra-pulmonary injection of 3,4-benzopyrene can steady induce lung carcinoma in rats, and green tea has preventive effect against lung cancer possibly by regulating expression of some critical genes such as p53 and bcl-2.
Author: A.L. Molan and J. Flanagan and W. Wei and P.J. Moughan
The effects of selenium-containing green tea (SGT; 1.4 mg selenium/kg) and China green tea (CGT; 0.13 mg selenium/kg) on the in vitro growth of lactobacilli and bifidobacteria were investigated using pure and mixed cultures. SGT had significantly higher phenolic contents (TPC), higher reducing activity, higher DPPH free-radical scavenging activity, and higher ferrous-ion chelating activity (P < 0.05–0.0001) than CGT. The addition of aqueous extracts from CGT to Mann-Rogosa-Sharpe (MRS) broth at 10% and 25% (v/v) resulted in small but nonsignificant (P > 0.05) increases in the numbers of Lactobacillus rhamnosusand Bifidobacterium breve over the control incubations (without tea). Addition of 10% and 25% of SGT extract resulted in a significant increase (P < 0.05–0.0001) in the number of lactobacilli and bifidobacteria recovered from batch fermentation while CGT did not increase the number of bifidobacteria. The higher prebiotic activity of SGT over CGT may be related to the higher TPC or minerals, notably selenium or a combination of these factors. To test whether selenium itself has an effect on bacterial growth, Na-selenite and Na-selenate were added alone or in combination with CGT to the MRS broth containing pure culture of L. rhamnosus. Growth of this bacterium was enhanced relative to the control incubation of MRS only. When added in combination with CGT, Na-selenate was more effective at enhancing the growth of L. rhamnosus than Na-selenite. The prebiotic effect of SGT could be largely explained by its selenium content.
Author: Ka H. Chan and Siu P. Ho and Sze C. Yeung and Wallace H.L. So and C.H. Cho and Marcel W.L. Koo and Wah K. Lam and Mary S.M. Ip and Ricky Y.K. Man and Judith C.W. Mak
Background Epigallocatechin-3-gallate (EGCG), which has been shown to have potent antioxidant effect, comprises 80% of catechins in Chinese green tea. This study was to investigate whether cigarette smoke (CS) exposure would induce lung morphological changes and oxidative stress in the CS-exposed rat model, and whether Chinese green tea (Lung Chen tea with EGCG as its main active ingredient) consumption would alter oxidative stress in sera and lung leading to protection of CS-induced lung damage. Methods Sprague-Dawley rats were randomly divided into four groups, i.e. sham air (SA), 4% CS, 2% Lung Chen tea plus SA or 4% CS. Exposure to SA or 4% CS was performed for 1 h/day for 56 days in ventilated smoking chambers. Sera and lung tissues were collected 24 h after last CS exposure for histology and all biochemical assays. Results Airspace enlargement and goblet cell hyperplasia were observed after 56-day CS exposure alone, which were abolished in the presence of green tea consumption. Serum 8-isoprostane level was significantly elevated (p<0.01) as well as lung superoxide dismutase (SOD) and catalase activities in CS-exposed rats compared to SA-exposed rats (p<0.05), which returned to the levels of SA-exposed rats after Chinese green tea consumption. Conclusion These results indicate that increased levels of systemic oxidative stress after CS exposure play an important role in the induction of lung damage. Chinese green tea may have the ability to suppress CS-induced oxidative stress that leads to protection of lung injury.
Author: Feng Li and Juan Xu and Jing Zhou and Liyan Zhao and Jianchun Sheng and Guiju Sun and Qiuhui Hu
The anticlastogenic effect of micrometer powder of selenium-enriched green tea (MSTP) was evaluated by using a chromosomal aberration assay in mouse testicular cells. Animals fed with a Se-deficient diet were treated with MSTP, micrometer powder of regular green tea (MRTP), selenite, and MRTP + selenite for 30 days by an intragastric route, followed by treatment of mitomycin C (MMC) on day 19 through intraperitoneal injection (ip). Selenium status and antioxidant enzymes were measured. Results indicated that MSTP showed a significant capability to reduce the incidence of MMC-induced chromosomal aberrations in spermatocytes from 22.7% to 6.7%. This inhibitory was highest, for MSTP, at 73.1%, while it was only 38.4% for MRTP. After 30 days of a Se-deficient diet, mice, either with or without the MMC treatment, showed a lower selenium concentration in blood and liver as well as lower enzyme activity of the antioxidants, GPx and SOD. Supplementation with MSTP, selenite, or selenite + MRTP enhanced the activities of these antioxidant enzymes. This enhancement was accompanied with a concomitant elevation of selenium levels, which favored the synthesis of the seleno-enzyme GPx and protected the cells from the MMC-induced oxidative stress. Our results indicate that MSTP is both able to prevent the chromosomal aberrations induced by MMC in mouse spermatocytes and to enhance GPx and SOD activity in blood serum and liver.
Author: Vadivel Senthil Kumaran and Karpagavinayagam Arulmathi and Periandavan Kalaiselvi
Objective The activities and capacities of antioxidant systems of tissue cells are declined during aging, leading to the gradual loss of pro-oxidant/antioxidant balance and accumulation of oxidative damage. Hence, the present study evaluated the role of green tea extract (GTE), rich in polyphenols, in combating age-associated macromolecular damage in rat cardiac tissue. Methods The antioxidant defense system, lipid peroxidation, protein oxidation, and redox status in heart tissue were studied using young and aged rats. Results Significant increases in lipid peroxidation, protein carbonyls, and marked decreases in glutathione redox status, protein thiols, and activities of enzymatic and non-enzymatic antioxidants were observed in aged rats compared with young rats. Supplementation of GTE (100 mg/kg of body weight per day) orally for 30 days ameliorated these changes significantly. Conclusion This study accredits GTE's antioxidant rejuvenating potency and its role in the amelioration of senescence-mediated redox imbalance in aged rat cardiac tissue.
Author: Etsuji Suzuki and Takashi Yorifuji and Soshi Takao and Hirokazu Komatsu and Masumi Sugiyama and Toshiki Ohta and Kazuko Ishikawa-Takata and Hiroyuki Doi
Purpose To investigate the association between green tea consumption and mortality from all causes, cancer, and cardiovascular disease (CVD) among elderly people. Methods In a population-based, prospective cohort study, a total of 14,001 elderly residents (aged 65–84 years), randomly chosen from all 74 municipalities in Shizuoka, Japan, completed questionnaires that included items about frequency of green tea consumption. They were followed for up to 6 years, from December 1999 to March 2006. Consequently, 12,251 subjects were analyzed to estimate the hazard ratios (HRs) for all-cause mortality, cancer, and CVD. Results Among 64,002 person-years, 1,224 deaths were identified (follow-up rate, 71.6%). The multivariate HRs and 95% confidence intervals (CIs) for CVD mortality compared those who consumed seven or more cups per day with those who consumed less than one cup per day, were 0.24 (0.14–0.40), 0.30 (0.15–0.61), and 0.18 (0.08–0.40) for total participants, men, and women, respectively. Although green tea consumption was not inversely associated with cancer mortality, green tea consumption and colorectal cancer mortality were inversely associated with a moderate dose-response relationship. Conclusions Green tea consumption is associated with reduced mortality from all causes and CVD. This study also suggests that green tea could have protective effects against colorectal cancer.