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: Sayyed Yazdan Asadi and Pouya Parsaei and Mehrdad Karimi and Sareh Ezzati and Alaleh Zamiri and Fereshteh Mohammadizadeh and Mahmoud Rafieian-kopaei
Green tea (Camellia sinensis) has anti-oxidant and anti-inflammatory properties and may enhance wound healing process. The present study, therefore, was aimed to examine the effect of green tea ethanolic extract on wound healing process. For this experimental study, 36 healthy male Wistar rats were randomly designated to three groups of A, B, and C which, respectively treated with, Vaseline + 0.6% green tea extract, Vaseline and normal saline for 21 days. Wounds' length and area were measured by caliper every other day and specimens were taken at 3rd, 12th, and 21st day for microscopical examinations. Data were analyzed by SPSS 16 using survival analysis (Breslowtest), repeated measured ANOVA, one-way ANOVA and Mann–Whitney. P < 0.05 was considered as statistically significant. The mean healing duration of surgical wounds in groups A and B was 14.66 and 20.66 (P = 0.018), respectively. Decrease in healing duration in the group A was significantly higher within the first two weeks compared with control groups (P = 0.05). Microscopic examinations also indicated a significant difference in wound healing process between groups A and C throughout the whole study duration as well as groups A and B during the 3rd week of the study (P < 0.05). Green tea extract could help wound healing process, probably effective on surgical wounds healing.
Author: Shahab Nootash and Najmeh Sheikhzadeh and Behzad Baradaran and Ali Khani Oushani and Mohammad Reza Maleki Moghadam and Katayoon Nofouzi and Amir Monfaredan and Leili Aghebati and Fatemeh Zare and Sadigheh Shabanzadeh
Present study elucidates the efficacy of green tea (Camellia sinensis) on growth performance, immune and antioxidant systems and cytokine gene expression in rainbow trout tissues. Green tea was supplemented at 20, 100, and 500 mg kg−1 diet and fed to fish (average weight: 23.5 g) for 35 days. No remarkable changes in growth performance were observed among all test groups. Lower lipid peroxidation product and higher superoxide dismutase activity were noted in fish received the medium dose of green tea. Significant increase in serum bactericidal activity and total protein were recorded in all treatment groups. All doses of green tea up-regulated Interleukin-1β transcription in the spleen, while Interleukin-1β mRNA level decreased significantly in the kidney of low dose of green tea. Interleukin-6 mRNA level was up-regulated in the spleen of high dose of green tea and liver of middle and high doses of green tea. High dose and medium dose of green tea up-regulated the interleukin-8 transcription in the kidney and liver, respectively. Meanwhile, green tea inhibited the production of interleukin-10 in all treatment groups compared with control group. Medium dose of green tea up-regulated tumor necrosis factor-α transcription in all fish tissues, while high dose and low dose of green tea enhanced tumor necrosis factor-α mRNA levels in the kidney and spleen, respectively. Present study suggests that green tea especially at 100 mg kg−1 feed may effectively enhance the antioxidant system and immune system in rainbow trout.
Author: Ugo Vertolli and Paul A. Davis and Lucia Dal Maso and Giuseppe Maiolino and Agostino Naso and Mario Plebani and Lorenzo A. Calò
Cardiovascular disease (CVD) remains the most common cause for excess morbidity and mortality in patients with chronic kidney disease (CKD) and end stage renal disease (ESRD) under chronic dialysis. ESRD patients have increased oxidative stress and endothelial dysfunction alongside increased levels of inflammation related proteins, which has prompted the exploration of anti-inflammatory and antioxidant treatments to improve outcomes. As green tea is increasingly well recognized for its antioxidant properties, we probed the effect of consumption of 1 capsule daily of green tea as a commercially available, decaffeinated green tea capsule (1 g, catechin content 68 mg) for 6 months on fibrinogen and inflammation in dialysis patients. Chronic hemodialysis patients (N = 25) were recruited and fibrinogen, FDP-D-dimer, high sensitivity (hs) CRP and the mononuclear cell protein expression of p22phox, were assessed before, i.e. baseline and after 6 months of ingestion of 1 green tea capsule per day. After 6 months of daily green tea capsule ingestion, dialysis patients showed reduced protein expression of p22phox (p < 0.0001), reduced hsCPR (p = 0.032) and fibrinogen (p = 0.022) levels and increased FDP-D-dimer (p = 0.0019) compared to their values at baseline. These results document lower oxidative stress and inflammation with green tea capsule ingestion and suggest a likely positive impact of green tea treatment on the atherosclerotic process of ESRD patients under dialysis.
Author: B. Giménez and A. López de Lacey and E. Pérez-Santín and M.E. López-Caballero and P. Montero
Active biodegradable films based on agar and agar–fish gelatin were developed by the incorporation of green tea aqueous extract to the film forming solution. The effect of the partial replacement of agar by fish skin gelatin as well as the addition of the green tea extract on the physical properties of the resultant films was evaluated. Special attention was given to the release of antioxidant and antimicrobial compounds from the agar film matrices with and without gelatin. Agar–gelatin films were less resistant and more deformable than agar films. The inclusion of green tea extract decreased tensile strength and elongation at break in both agar and agar–gelatin films. Water vapour permeability and water resistance was not affected either by the replacement of agar by gelatin or the addition of green tea extract, but the water solubility noticeably increased in the films containing green tea extract. The presence of gelatin in the agar–green tea matrix film hindered the release of total phenolic compounds, catechins and flavonols in water. As a consequence, the antioxidant power released by the films was lower in the case of films containing gelatin. However, the antimicrobial activity of the films was not affected by the presence of gelatin.
Author: Hideki Kanda and Peng Li and Hisao Makino
We developed a new technique for green tea decaffeination involving ingredient extraction and drying of green tea leaves by using liquefied dimethyl ether (DME) as a safe extraction solvent. After hot water extraction with water content of 74.6–76.2%, green tea leaves were tested to verify the DME extraction in both laboratory- and bench-scale processes. The distributions of caffeine and catechins in the extracted residue, organic extracts, and removed water were tested by high-performance liquid chromatography. Caffeine was completely removed from the green tea leaves. Approximately 25.2–56.0% of catechins remained in the residue after DME extraction. In particular, 56.0% of epigallocatechin gallate, which has the greatest activity of all catechins remained in the residue.
Author: Min Ju Kim and K.M. Maria John and Jung Nam Choi and Sarah Lee and Ah Jin Kim and Young Mi Kim and Choong Hwan Lee
Metabolomic differences between green tea (GT) and Aspergillus oryzae-fermented green tea (FGT) were investigated using Liquid Chromatography–Electrospray Ionization-Ion Trap–Tandem Mass Spectrometry (LC-ESI-IT-MS/MS). To identify the metabolomic differences, principal component analysis (PCA) and orthogonal projection to latent structures discriminate analysis (OPLS-DA) of GT and FGT were performed. A total of 17 metabolites differed between GT and FGT. The major flavonoid compounds of GT, epigallocatechin gallate (EGCG) and epicatechin gallate (ECG), decreased during fermentation, while the levels of phenolic compounds, such as gallic acid, 3-p-coumaroylquinic acid, and other flavonoid metabolites like gallocatechin, epicatechin, and epigallocatechin, increased significantly during fermentation. Notably, caffeine degradation was also observed during fermentation of GT by A. oryzae. Although the total flavonoid content of FGT decreased, the antioxidant activity of FGT increased significantly due to increased levels of other identified and unidentified metabolites. These results show that fermentation-dependent metabolomic changes have the potential to increase the bioactivity of GT.
Author: Jin-Ye Fu and Jing Gao and Zhi-Yuan Zhang and Jia-Wei Zheng and Jian-Feng Luo and Lai-Ping Zhong and Yong-Bing Xiang
Objectives To evaluate the relation of tea consumption with the risk of oral cancer incidence. Subjects and methods A multicenter case-control study based on hospitalized population was conducted for evaluating the association of tea consumption with oral cancer risk in China. Black tea and green tea were separately analyzed. 723 cases and 857 controls were included. Unconditional multiple logistic regression model was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) of oral cancer for tea consumption. Results The ORs for green tea consumption ⩾8 g/day compared with <4 g/day were 0.72 (95% CI 0.54, 0.93) for men, and 0.93 (95% CI 0.74, 1.26) for women. The ORs for black tea consumption ⩾6 g/day compared with <2 g/day were 0.97 (95% CI 0.74, 1.20) for men, and 0.91 (95% CI 0.68, 1.23) for women. Green tea intake was significantly associated with reduced risk of oral cancer in men, but not in women, and the association was stronger in heavily smoking men. There was no indication that black tea consumption was associated with decreased oral cancer risk. Conclusion The results of this study indicated that green tea consumption may decrease the risk of oral cancer in men especially for those smoking heavily.
Author: Yanlan Xie and Agnieszka Kosińska and Hairong Xu and Wilfried Andlauer
The effect of milk on the absorption of polyphenols is still controversial so far. In order to determine the impact of milk addition on green tea catechins bioaccessibility and intestinal absorption an in vitro digestion/Caco-2 cell model was applied. Green tea extract (GTE) was solubilized in distilled water at 23 °C and 100 °C, combined with skimmed milk (GTE + 10% milk and GTE + 25% milk) and subjected to simulated gastric and intestinal digestion, followed by transepithelial absorption in Caco-2 cells monolayers. In the mixture with milk, gallated catechins: ECG and EGCG showed binding to milk proteins while EC and EGC seemed to have weaker affinity. Catechins were stable during gastric incubation and very sensitive to intestinal digestion. Bioaccessibility of green tea catechins brewed at 100 °C was higher than brewed at 23 °C. Catechins from digested GTE with 10% and 25% milk exhibited enhanced intestinal permeability in Caco-2 model in comparison to non-digested GTE and digested GTE without milk. Apparent permeability coefficients (Papp) of EGCG and ECG in digested GTE with 25% milk were significantly higher compared to those in GTE with 10% milk, and amounted to 2.41 × 10− 6 cm/s and 1.39 × 10− 6 cm/s. The recoveries of all catechins in GTE with milk in Caco-2 cells after 2 h incubation were significantly higher than that without milk. To summarize, these data suggest that milk addition may increase catechin bioavailability by enhancing their transepithelial absorption and uptake from green tea extract.
Author: Chung S. Yang and Guangxun Li and Zhihong Yang and Fei Guan and Amber Chen and Jihyeung Ju
Tocopherols (vitamin E) and tea polyphenols have been reported to have cancer preventive activities. Large-scale human trials with high doses of alpha-tocopherol, however, have produced disappointing results. This review presents data showing that - and -tocopherols inhibit colon, lung, mammary and prostate carcinogenesis in animal models, whereas -tocopherol is ineffective in animal and human studies. Possible mechanisms of action are discussed. A broad cancer preventive activity of green tea polyphenols has been demonstrated in animal models, and many mechanisms have been proposed. The cancer preventive activity of green tea in humans, however, has not been conclusively demonstrated and remains to be further investigated.
Author: B. Giménez and S. Moreno and M.E. López-Caballero and P. Montero and M.C. Gómez-Guillén
A green tea aqueous extract was prepared and blended at different percentages (2, 4 and 8%) with a commercial fish-skin gelatin in order to provide gelatin films with antioxidant capacity. This green tea extract proved to be an efficient antioxidant at non-cytotoxic concentrations. Gelatin films with green tea extract were subjected to enzymatic digestion with pepsin (gastric digestion) and with pepsin, trypsin and chymotrypsin (gastrointestinal digestion). The gelatin matrix was efficiently hydrolysed during gastrointestinal digestion and protein hydrolysates composed of low molecular weight peptides, regardless the content of green tea extract, were obtained in all the formulations. High percentages of total polyphenols were recovered from the films with green tea extract after gastrointestinal digestion, although a significant degradation of the major catechins of the green tea (EGCG and EGC) was observed. The increase of the content of green tea extract in the film formulation gave an increase in the antioxidant activity released from the film samples after enzymatic digestion. 85–100% of the maximum expected antioxidant activity was recovered after both gastric and gastrointestinal digestion in spite of the degradation observed of EGCG and EGC.