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
Author: A.M. López de Lacey and M.E. López-Caballero and P. Montero
A bioactive film composed of agar, incorporating green tea extract and probiotic strains (Lactobacillus paracasei L26 and Bifidobacterium lactis B94) was applied on hake fillets in order to evaluate the effect of the films during 15 days of storage. Hake was previously inoculated with Shewanella putrefaciens and Photobacterium phosphoreum (103–104 CFU/g) to simulate a spoilage process. The green tea and/or probiotic film provoked a reduction, particularly of H2S-producing bacteria counts and total viable bacteria throughout the storage period. The probiotic strains added to the film could pass to the fish producing an increment of lactic acid bacterial counts, even in the presence of green tea extract. The effect of the films also caused a decrease in the indexes of fish quality (total volatile basic nitrogen (TVB-N), trimethylamine nitrogen (TMA-N) and pH). The total viable counts, H2S-producing microorganisms and TVB-N were maintained below the limits of acceptability during 15 days for the fillet covered with the green tea + probiotic film, compared to the rest of the samples. Films with green tea and probiotic were able to extend shelf-life of hake at least for a week and increase the beneficial lactic acid bacteria in fish.
Author: Chahira Snoussi and Robert Ducroc and Mohamed Hédi Hamdaoui and Karima Dhaouadi and Houda Abaidi and Francoise Cluzeaud and Corinne Nazaret and Maude Le Gall and André Bado
Green tea containing polyphenols exerts antidiabetic and antiobesity effects, but the mechanisms involved are not fully understood. In this study, we first analyzed and compared polyphenol compounds [epigallocatechin gallate (EGCG), epigallocatechin (EGC)] in decoction of green tea leaves versus usual green tea extracts. Second, the effects of acute (30 min) or chronic (6 weeks) oral administration of green tea decoction (GTD) on intestinal glucose absorption were studied in vitro in Ussing chamber, ex vivo using isolated jejunal loops and in vivo through glucose tolerance tests. Finally, we explore in rat model fed normal or high-fat diet the effects of GTD on body weight, blood parameters and on the relative expression of glucose transporters SGLT-1, GLUT2 and GLUT4. GTD cooked for 15 min contained the highest amounts of phenolic compounds. In fasted rats, acute administration of GTD inhibited SGLT-1 activity, increased GLUT2 activity and improved glucose tolerance. Similarly to GTD, acute administration of synthetic phenolic compounds (2/3 EGCG+1/3 EGC) inhibited SGLT-1 activity. Chronic administration of GTD in rat fed high-fat diet reduced body weight gain, circulating triglycerides and cholesterol and improved glucose tolerance. GTD-treated rats for 6 weeks display significantly reduced SGLT-1 and increased GLUT2 mRNA levels in the jejunum mucosa. Moreover, adipose tissue GLUT4 mRNA levels were increased. These results indicate that GTD, a traditional beverage rich in EGCG and EGC reduces intestinal SGLT-1/GLUT2 ratio, a hallmark of regulation of glucose absorption in enterocyte, and enhances adipose GLUT4 providing new insights in its possible role in the control of glucose homeostasis.
Author: Danqun Huo and Yu Wu and Mei Yang and Huanbao Fa and Xiaogang Luo and Changjun Hou
Colorimetric artificial tongue and nose were used to discriminate nine Chinese green teas from different geographical origins and grade levels. Printing nanoporous porphyrin, dimeric metalloporphyrins, metallosalophen complexes and chemically responsive dyes on a hydrophobic membrane, the developed sensor array of artificial tongue and nose showed a unique pattern of colorimetric change upon exposure to green tea liquids or gases. All green tea samples, both in liquid and gas analysis, gave distinct patterns according to geographical origin and grade level, thus resulting in their facile identification. The good reproducibility of colorimetric artificial tongue and nose was proved. Data analysis was performed by chemometric techniques: hierarchical cluster analysis (HCA), and principal component analysis (PCA). Chinese green tea from the same geographical origin could cluster together in PCA score plot. No errors in classification by HCA were observed in 90 trials. The colorimetric artificial tongue and nose can be used to discriminate Chinese green tea according to geographical origin and grade level.
Author: Yu-Wen Hsu and Chia-Fang Tsai and Hung-Chih Ting and Wen-Kang Chen and Cheng-Chieh Yen
Catechin composition of green tea extract and its anti-senescence effect was investigated with a study of senescence-related redox imbalance in the brains of aged mice. Oral administration of green tea extract at doses of 125, 625 and 1250 mg/kg for 4 weeks alleviated the senescence-mediated redox imbalance, as observed from the significantly reduced (p < 0.05) levels of thiobarbituric acid-reactive substances (TBARS) in the serum and increased glutathione (GSH) and total thiol levels in the plasma compared with that in the aged control group. Moreover, the activities of superoxide dismutase (SOD), catalase, glucose-6-phosphate dehydrogenase (G6PD), glutathione peroxidase (GSH-Px) and glutathione reductase (GSH-Rd) in the brain were also increased, whereas protein carbonyls were reduced. Taken together, these results clearly indicate that green tea extract exhibits potent protective effects against senescence-mediated redox imbalance in the brains of mice by inhibiting oxidative damage and increasing antioxidant enzyme activities.
Author: Yanmang Cui and Xingbin Yang and Xinshan Lu and Jinwen Chen and Yan Zhao
The study was to characterize the polyphenolic composition, antioxidant properties, and hepatoprotective effects of a polyphenols-enriched extract (HMTP) from Huangshan Maofeng green tea. HPLC analysis showed that three predominantly polyphenolic compounds present in HMTP were epigallocatechin (271.2μg/mg extract), rutin (239.3μg/mg) and epicatechin (89.3μg/mg). HMTP was shown to exhibit strong scavenging activities against DPPH, O2−, and OH, and ferric-reducing antioxidant power in vitro. Administration of HMTP at 200, 400 and 800 mg/kg bw in mice prior to CCl4 injury significantly decreased the CCl4-induced elevation of serum ALT, AST and ALP activities, and prevented an increase in hepatic MDA levels (p < 0.05). Mice with HMTP pretreatment displayed a better profile of hepatosomatic index and the improved GSH-Px and SOD activities in the liver, relative to CCl4-intoxicated mice. Liver pathological observation also confirmed the protection on CCl4-caused histological alteration, suggesting that HMTP has potential to be explored as valuable hepatoprotective function food.
Author: Ali Rashidinejad and E. John Birch and Dongxiao Sun-Waterhouse and David W. Everett
The encapsulation of green tea catechin and epigallocatechin gallate (EGCG) in soy lecithin liposomes was examined at four concentrations (0%, 0.125%, 0.25% and 0.5% w/v), and inclusion in cheese at 0% and 0.25% w/v. The empty capsules had a mean diameter of 133nm and significantly (p < 0.05) increased with the addition of catechin or EGCG. Electron microscopy revealed the lamellae and central core of the liposomes. Addition of antioxidants gave a significant (p < 0.05) increase in the size of liposomes. Liposomes had surface potentials of −42.4 to −46.1 mV with no significant difference between treatments, suggesting stable liposome systems. High efficiency (>70%) and yield (∼80%) were achieved from the incorporation of catechin or EGCG inside the liposome structure. Addition of either antioxidant increased the liposome phase transition temperature (>50°C). Nanocapsules containing these antioxidants were effectively retained within a low-fat hard cheese, presenting a simple and effective delivery vesicle for antioxidants.
Author: Anna Marchese and Erika Coppo and Anatoly P. Sobolev and Daniela Rossi and Luisa Mannina and Maria Daglia
The antistaphylococcal activity as well as the metabolic profiling and polyphenols content of green tea (Camellia sinensis) before and after in vitro simulated gastric, duodenal and gastroduodenal digestion were investigated. Gastric and duodenal digested samples showed antistaphylococcal activity, whereas gastroduodenal digested samples did not show any antibacterial activity. Metabolite analysis, carried out using an explorative untargeted NMR-based approach and a RP-HPLC-PAD-ESI–MSn method, showed that green tea polyphenols are stable under gastric conditions. Duodenal digested sample maintained the antibacterial activity, even if some polyphenols are widely degraded. Epicatechin 3-gallate, under duodenal digestive conditions, is hydrolyzed to produce epicatechin, whereas epigallocatechin 3-gallate reacts with digestive enzymes and a galloyl-high molecular weight derivative is produced. Gastroduodenal digestion results in degradation of polyphenols, especially gallocatechins, considered the main responsible for the antibacterial activity. These results explain the loss of activity of gastroduodenal digested samples and why in vivo green tea has neither protective nor therapeutic effects against intestinal and systemic bacterial infections.
Author: Yang-Hee Hong and Eun Young Jung and Dong Ouk Noh and Hyung Joo Suh
Background Green tea contains numerous polyphenols, which have health-promoting effects. The purpose of this study was to evaluate the effect of tannase-converted green tea extract (TGE) formulation on the physical stability and activities of skin-related enzymes. Methods Physical stability was evaluated by measuring the pH, precipitation, and colors at 25 ± 2°C/ambient humidity and at 40 ± 2°C/70% ± 5% relative humidity for 4 months. Activities of collagenase, elastase, and tyrosinase as skin-related enzymes were assessed on TGE formulation. Results The concentrations of epigallocatechin-3-gallate and epicatechin-3-gallate in green tea extract were greatly decreased to the extent of negligible level when treated with tannase. The formulation containing 5% tannase-converted green tea extract showed relatively stable pH, precipitation, and color features for 16 weeks. When TGE was added to the formulation, there was a significant increase in the inhibition of elastase and tyrosinase activities (p < 0.05) compared with the formulation containing 5% normal green tea extract. Conclusion The TGE could be used in cosmetics as skin antiwrinkling or depigmenting agent.
Author: Mara Mirasoli and Roberto Gotti and Massimo Di Fusco and Alberto Leoni and Carolina Colliva and Aldo Roda
Electronic nose and capillary electrophoresis were applied in quality control of green tea samples subjected to long-term storage. Twelve representative green teas were considered, available as an “aged” (tea leaves stored during a long-term period of two years) and/or “not aged” (fresh products) samples. Their infusions were analyzed by an electronic nose, equipped with an array of six metal oxide semiconductor (MOS) sensors to obtain olfactive fingerprints of the volatile compounds in the infusions headspace. Upon training and chemometric analysis of acquired data (linear discriminant analysis), the electronic nose was found to be able in correctly classifying unknown samples as “aged” or “not aged”. Concomitantly, the infusion samples were analyzed by Cyclodextrin-modified Micellar Electrokinetic Chromatography (CD-MEKC) for determination of catechins. The analysis of seven most represented catechins and the methylxanthines theobromine and caffeine revealed a general loss of the polyphenols in each of the considered aged samples (up to 45%, w/w). In addition, the applied enantioselective method based on (2-hydroxypropyl)-β-cyclodextrin (HP-βCD) as chiral selector, was exploited for the estimation of (+)-Gallocatechin in the presence of (−)-Gallocatechin; the latter, as the non-native enantiomer, can be associated to the epimerisation of (−)-Epigallocatechin and was assumed as a marker occurring in case of uncorrected storage conditions of tea leaves. Interestingly, it was observed that epimerization did not significantly occur during aging. The application of CD-MEKC and electronic nose allowed for a fast characterization of green teas taking into account that the aroma is a decisive parameter for the acceptance of the product, whereas the catechins content is associated to the biological value.
Author: Kayleigh A. Clarke and Tristan P. Dew and Rachel E.B. Watson and Mark D. Farrar and Susan Bennett and Anna Nicolaou and Lesley E. Rhodes and Gary Williamson
The simultaneous analysis of free-form and conjugated flavonoids in the same sample is difficult but necessary to properly estimate their bioavailability. A method was developed to optimise the extraction of both free and conjugated forms of catechins and metabolites in a biological sample following the consumption of green tea. A double-blind randomised controlled trial was performed in which 26 volunteers consumed daily green tea and vitamin C supplements and 24 consumed a placebo for 3 months. Urine was collected for 24 h at 4 separate time points (pre- and post-consumption) to confirm compliance to the supplementation and to distinguish between placebo and supplementation consumption. The urine was assessed for both free and conjugated metabolites of green tea using LC–MS2 analysis, after a combination extraction method, which involved an ethyl acetate extraction followed by an acetonitrile protein precipitation. The combination method resulted in a good recovery of EC-O-sulphate (91 ± 7%), EGC-O-glucuronide (94 ± 6%), EC (95 ± 6%), EGC (111 ± 5%) and ethyl gallate (74 ± 3%). A potential total of 55 catechin metabolites were investigated, and of these, 26 conjugated (with methyl, glucuronide or sulphate groups) and 3 free-form (unconjugated) compounds were identified in urine following green tea consumption. The majority of EC and EGC conjugates significantly increased post-consumption of green tea in comparison to baseline (pre-supplementation) samples. The conjugated metabolites associated with the highest peak areas were O-methyl-EC-O-sulphate and the valerolactones M6/M6′-O-sulphate. In line with previous studies, EC and EGC were only identified as conjugated derivatives, and EGCG and ECG were not found as mono-conjugated or free-forms. In summary, the method reported here provides a good recovery of catechin compounds and is appropriate for use in the assessment of flavonoid bioavailability, particularly for biological tissues that may contain endogenous deconjugating enzymes.