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.
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Heart 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.”
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Mental 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
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Cancer 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.
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Immunity
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
“Do you want a vodka? No, a green tea please!” Epigallocatechin gallate and its possible role in oxidative stress and liver damage
Author: Lorenzo Leggio and Giovanni Addolorato
Author: Bing Hu and Lin Wang and Bei Zhou and Xin Zhang and Yi Sun and Hong Ye and Liyan Zhao and Qiuhui Hu and Guoxiang Wang and Xiaoxiong Zeng
Monomers of (−)-epigallocatechin (EGC), (−)-epigallocatechin gallate (EGCG), (−)-epicatechin (EC), (−)-epicatechin gallate (ECG), (−)-epigallocatechin 3-O-(3-O-methyl) gallate (EGCG3″Me) and (−)-3-O-methyl epicatechin gallate (ECG3′Me) (purity, >97%) were successfully prepared from extract of green tea by two-time separation with Toyopearl HW-40S column chromatography eluted by 80% ethanol. In addition, monomers of (−)-catechin (C), (−)-gallocatechin (GC), (−)-gallocatechin gallate (GCG), and (−)-catechin gallate (CG) (purity, >98%) were prepared from EC, EGC, EGCG, and ECG by heat-epimerization and semi-preparative HPLC chromatography. With the prepared catechin standards, an effective and simultaneous HPLC method for the analysis of gallic acid, tea catechins, and purine alkaloids in tea was developed in the present study. Using an ODS-100Z C18 reversed-phase column, fourteen compounds were rapidly separated within 15 min by a linear gradient elution of formic acid solution (pH 2.5) and methanol. A 2.5–7-fold reduction in HPLC analysis time was obtained from existing analytical methods (40–105 min) for gallic acid, tea catechins including O-methylated catechins and epimers of epicatechins, as well as purine alkaloids. Detection limits were generally on the order of 0.1–1.0 ng for most components at the applied wavelength of 280 nm. Method replication generally resulted in intraday and interday peak area variation of <6% for most tested components in green, Oolong, black, and pu-erh teas. Recovery rates were generally within the range of 92–106% with RSDs less than 4.39%. Therefore, advancement has been readily achievable with commonly used chromatography equipments in the present study, which will facilitate the analytical, clinical, and other studies of tea catechins.
Author: Rossana M. Costa and Ana S. Magalhães and José A. Pereira and Paula B. Andrade and Patrícia Valentão and Márcia Carvalho and Branca M. Silva
This study aimed to determine the phenolic profile and to investigate the antioxidant potential of quince (Cydonia oblonga) leaf, comparing it with green tea (Camellia sinensis). For these purposes, methanolic extracts were prepared and phenolics content of quince leaf was determined by HPLC/UV. The antioxidant properties were assessed by Folin–Ciocalteu reducing capacity assay and by the ability to quench the stable free radical 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and to inhibit the 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative hemolysis of human erythrocytes. 5-O-Caffeoylquinic acid was found to be the major phenolic compound in quince leaf extract. Quince leaf exhibited a significantly higher reducing power than green tea (mean value of 227.8 ± 34.9 and 112.5 ± 1.5 g/kg dry leaf, respectively). Quince leaf extracts showed similar DPPH radical-scavenging activities (EC50 mean value of 21.6 ± 3.5 μg/ml) but significantly lower than that presented by green tea extract (EC50 mean value of 12.7 ± 0.1 μg/ml). Under the oxidative action of AAPH, quince leaf methanolic extract significantly protected the erythrocyte membrane from hemolysis in a similar manner to that found for green tea (IC50 mean value of 30.7 ± 6.7 and 24.3 ± 9.6 μg/ml, respectively, P > 0.05). These results point that quince leaf may have application as preventive or therapeutic agent in diseases in which free radicals are involved.
Author: Min-Jer Lu and Sheng-Che Chu and Lipyng Yan and Chinshuh Chen
Effect of tannase enzymatic treatment on protein–tannin aggregation and sensory attributes of green tea infusion was investigated. Green tea leaves were extracted with hot water at 85 °C for 20 min, the tea infusion was then treated with tannase. Results showed that both EGCG and ECG of the tea catechins were hydrolyzed by tannase into EGC and EC, respectively, accompanied by production of gallic acid. The tannase-treated tea infusion had a relatively lower binding ability with protein. Changes in the content of tea catechins, formation of tea cream, and turbidity of tea infusion with or without tannase treatment were measured after 4 weeks. Content of catechins in the tannase-modified tea remained almost unchanged, while those without tannase treated (control) decreased significantly (p < 0.05). Meanwhile, better color appearance and less tea cream formation were observed for the tannase-treated green tea, and tea cream formed for the control after storage. Results of the sensory evaluation showed that mouth feeling, taste and the overall acceptance of the tannase-treated green tea infusion were all better than those of the control.
Author: Calin Stoicov and Reza Saffari and JeanMarie Houghton
Helicobacter infection, one of the most common bacterial infections in man worldwide, is a type 1 carcinogen and the most important risk factor for gastric cancer. Helicobacter pylori bacterial factors, components of the host genetics and immune response, dietary cofactors and decreased acid secretion resulting in bacterial overgrowth are all considered important factors for induction of gastric cancer. Components found in green tea have been shown to inhibit bacterial growth, including the growth of Helicobacter spp. In this study, we assessed the bactericidal and/or bacteriostatic effect of green tea against Helicobacter felis and H. pylori in vitro and evaluated the effects of green tea on the development of Helicobacter-induced gastritis in an animal model. Our data clearly demonstrate profound growth effects of green tea against Helicobacter and, importantly, demonstrate that green tea consumption can prevent gastric mucosal inflammation if ingested prior to exposure to Helicobacter infection. Research in the area of natural food compounds and their effects on various disease states has gained increased acceptance in the past several years. Components within natural remedies such as green tea could be further used for prevention and treatment of Helicobacter-induced gastritis in humans.
Author: Xi Jun
A new method using high pressure processing to extract caffeine from green tea leaves was studied. The effect of different parameters such as high hydrostatic pressure (100–600 MPa), different solvents (acetone, methanol, ethanol and water), ethanol concentration (0–100% mL/mL), pressure holding time (1–10 min) and liquid/solid ratio (10:1 to 25:1 mL/g) were studied for the optimal caffeine extraction from green tea leaves. The highest yields (4.0 ± 0.22%.) were obtained at 50% (mL/mL) ethanol concentration, liquid/solid ratio of 20:1 (ml/g), and 500 MPa pressure applied for 1 min. Experiments using conventional extraction methods (extraction at room temperature, ultrasonic extraction and heat reflux extraction) were also conducted, which showed that extraction using high pressure processing possessed several advantages, such as higher yields, shorter extraction times and lower energy consumption.
Author: Quansheng Chen and Jiewen Zhao and Sumpun Chaitep and Zhiming Guo
This paper reported the results of simultaneous analysis of main catechins (i.e., EGC, EC, EGCG and ECG) contents in green tea by the Fourier transform near infrared reflectance (FT-NIR) spectroscopy and the multivariate calibration. Partial least squares (PLS) algorithm was conducted on the calibration of regression model. The number of PLS factors and the spectral preprocessing methods were optimised simultaneously by cross-validation in the model calibration. The performance of the final model was evaluated according to root mean square error of cross-validation (RMSECV), root mean square error of prediction (RMSEP) and correlation coefficient (R). The correlations coefficients (R) in the prediction set were achieved as follows: R = 0.9852 for EGC model, R = 0.9596 for EC model, R = 0.9760 for EGCG model and R = 0.9763 for ECG model. This work demonstrated that NIR spectroscopy with PLS algorithm could be used to analyse main catechins contents in green tea.
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.