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: Yoshinori Masukawa and Yuji Matsui and Namii Shimizu and Naoki Kondou and Hidenori Endou and Michiya Kuzukawa and Tadashi Hase
A method for the sensitive and specific determination of eight green tea catechins, consisting of catechin (C), epicatechin (EC), gallocatechin (GC), epigallocatechin (EGC), catechin-3-gallate (CG), epicatechin-3-gallate (ECG), gallocatechin-3-gallate (GCG) and epigallocatechin-3-gallate (EGCG), in human plasma was established. For optimization of conditions for LC–ESIMS, the separation of the eight catechins was achieved chromatographically using Inertsil ODS-2 column combined with a gradient elution system of 0.1 M aqueous acetic acid and 0.1 M acetic acid in acetonitrile. Detection using a mass spectrometer was performed with selected ion monitoring at m/z = 289 for E and EC, 305 for GC and EGC, 441 for CG and ECG, and 457 for GCG and EGCG under negative ESI. A preparative procedure, consisting of the addition of perchloric acid and acetonitrile to the plasma for deproteinizing and the subsequent addition of potassium carbonate solution to remove excess acid, was developed. In six different plasma with the eight catechins spiked at two different concentrations, the average recoveries were in the range between 72.7 and 84.1%, which resulted from the matrix effect and preparative loss, with coefficients of variance being 8.2–19.8% among individuals. The levels of the catechins in prepared plasma solutions that were kept at 5 °C within 24 h were stable, which allows us to simply analyze many prepared plasma solutions using an autosampler overnight. When using this method to analyze the eight catechins in human plasma after oral ingestion of a commercial green tea beverage, we detected all the catechins absorbed into human blood for the first time. This also suggested that extremely small amounts of the eight catechins orally ingested may be absorbed based on each absorptive property for the catechins. The method should enable pharmacokinetic studies of green tea catechins in humans.
Author: Sreeparna Banerjee
The high polyunsaturated fatty acid content of oily fish such as mackerel (Scomber scombrus) makes it particularly susceptible to oxidative degradation. We have shown previously the presence of lipoxygenase (LOX), a lipid oxygenase, in mackerel muscle. In the current study, commercially available green tea polyphenols were shown to effectively inhibit the LOX activity of mackerel muscle. EGCG (epigallocatechin gallate) was the strongest inhibitor tested with an IC50 (concentration for half maximal inhibition) value of 0.13 nM. All the tea catechins showed a mixed non-competitive type inhibition. In addition, antioxidants such as BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene), esculetin, caffeic acid, ascorbic acid, and ethylene diamine tetraacetic acid (EDTA) were effective to varying degrees (IC50 values between 0.02 and >50 μM) in the inhibition of mackerel muscle LOX. Nordihydroguaiaretic acid (NDGA), a classical LOX inhibitor and potassium cyanide (KCN), a heme protein inhibitor were assayed for their inhibitory activities for comparison. Post harvest spoilage of fish account for loss of as much as 10% of the world’s catches of cultured fish. This data indicates that the green tea polyphenols, nature’s very potent antioxidants, may be used as an effective and natural means of reducing post harvest spoilage in fish.
Author: Periasamy Srinivasan and Kuruvimalai Ekambaram Sabitha and Chennam Srinivasulu Shyamaladevi
Green tea polyphenols (GTP) has been used as a chemopreventive agent world wide against chemically induced cancer. The present study is aimed to understand the therapeutic action of GTP on glycoconjugates and immunological markers in 4-Nitroquinoline 1-oxide (4-NQO)-induced oral cancer over a period of 30 days at 200 mg/kg, p.o., Oral cancer was induced by painting 4-NQO for 8 weeks followed by administration of GTP after 22 weeks, for 30 days. Glycoconjugates such as hexose, hexosamine, sialicacid, fucose and mucoprotein were analysed. Expression of glycoconjugates was examined through histology and SDS-PAGE. Immunological markers such as circulating immune complex and mast cell density were studied. Oral cancer-induced animals showed a significant increase in levels of glycoconjugates and its expression, similar to that observed for immunological markers. Treatment with GTP altered the expression of glycoconjugates as well as immunological markers. The results suggest that GTP modulates both the expression of glycoconjugates and immunological markers resulting in regression of oral cancer.
Author: Susana Coimbra and Alice Santos-Silva and Petronila Rocha-Pereira and Susana Rocha and Elisabeth Castro
Cardiovascular disease is the major cause of mortality and morbidity in the Western world. Green tea prepared with leaves of Camellia sinensis is particularly rich in antioxidants, which seem to have a crucial role in atherogenesis. The aim of our investigation was to evaluate the effect of green tea drinking on the lipid profile in 29 Portuguese subjects. The lipid profile included the measurement of total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, triacylglycerols, apolipoprotein A-I, apolipoprotein B, and lipoprotein(a). The measurements were performed at the beginning of the study, and after 3 weeks of drinking 1 L of water, and after 4 weeks of drinking 1 L of green tea daily. Tea was prepared every day at the same conditions of temperature, time of infusion, and concentration. No dilution effect was observed after water drinking. After drinking green tea, a significant beneficial improvement in the lipid profile of subjects was observed. A decrease in cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, and ratio of cholesterol/HDL-C, but an increase in HDL-C and apolipoprotein A-I, was observed in the subjects. No significant differences were observed for triacylglycerol and lipoprotein(a). Our data suggest that drinking green tea has a beneficial effect protecting against the risk for cardiovascular disease by improving blood lipid levels.
Author: Shin-Pei Yang and Kimberly Wilson and Abdul Kawa and Gregory M. Raner
Green tea extract is known to contain compounds that are able to produce antioxidant effects in many types of living cells. Treatment of cultured human hepatoma (HepG2) cells with green tea extract resulted in dramatically increased expression of at least 15 genes that are present on a commercial human drug metabolism gene array. RT-PCR was used to confirm the microarray results, and analysis of the 5′-flanking region of each of these genes revealed potential electrophile/antioxidant response elements. Members of the acetyl transferase, epoxide hydrolase, sulfotransferase and glutathione transferase gene families were strongly induced. In addition, the human tongue carcinoma cell line Cal-27 did not respond to green tea extract in the same way, as none of the induced genes in the HepG2 cells were induced in the Cal-27 cells. The lack of induction of detoxification enzymes in the Cal-27 cell line may help to explain the previously observed increased cytotoxicity of green tea catechins on this cell line.
Author: Susana Coimbra and Elisabeth Castro and Petronila Rocha-Pereira and Irene Rebelo and Susana Rocha and Alice Santos-Silva
Summary Background & aims Green tea, an infusion prepared with the leaves of Camellia sinensis is particularly rich in flavonoids, which are strong antioxidants. Tea drinking, by providing antioxidants, may become valuable in several oxidative stress conditions. Our aim was to evaluate the effect of green tea drinking on some factors reflecting the development of oxidative stress in plasma and in erythrocytes. Methods The study was performed in 34 Portuguese subjects. We evaluated the total antioxidant status (TAS), the lipid peroxidation products—malonyldialdehyde (MDA) and malonyldialdehyde+4-hydroxy-2(E)-nonenal (MDA+4-HNE)—and the oxidative changes in erythrocyte membrane, namely membrane bound haemoglobin (MBH) and the band 3 profile. Analytical evaluations were performed after 3 weeks drinking 1l of water daily, and after 4 weeks drinking 1l of green tea daily. Tea was prepared daily at the same conditions of temperature, time of infusion and concentration. Results After green tea drinking, we found a significant reduction in serum levels of MDA and MDA+4-HNE and in the oxidative stress within the erythrocyte, as suggested by a significantly lower value of MBH and by changes in band 3 profile towards a normal mean profile, namely an increase in the band 3 monomer. A rise in the antioxidant capacity was also observed. Conclusions Our data suggest for green tea drinking a beneficial effect, by reducing the development or the enhancement of oxidative stress and, therefore, protecting the individual for oxidative stress diseases. Moreover, we propose further studies about the value of band 3 profile and of MBH in providing a cumulative measurement of the effect of green tea drinking upon the oxidative stress in cells. Moreover, further studies are also needed, to clarify the effect of green tea consumption, the value of regular green tea consumption and the way it should be prepared to reach a healthy effect.
Author: Isidora Alexandropoulou and Michael Komaitis and Maria Kapsokefalou
The hypothesis that interactions of dietary polyphenols with dietary iron occur during digestion and result in a decrease of the post-absorptive antioxidant properties of polyphenols was investigated. The hypothesis was tested in vitro, under conditions that simulate gastrointestinal digestion. Mixtures of green tea, iron, and three dietary factors that modify the form of iron in the lumen, namely ascorbic acid, meat or casein, were subjected to an in vitro gastrointestinal digestion. Antioxidant capacity (FRAP assay), iron concentration (ferrozine assay) and polyphenol concentration (Folin–Ciocalteau assay) were measured in the in vitro digests. The presence of iron decreased the antioxidant capacity and the polyphenol concentration of green tea digests. The presence of ascorbic acid increased, while meat and casein decreased the antioxidant capacity of green tea. The factorial analysis of the data suggests that protein and iron interact with green tea polyphenols during the in vitro digestion and decrease their antioxidant capacity. These results support the aforementioned hypothesis.
Author: J. Khatiwada and M. Verghese and L.T. Walker and L. Shackelford and C.B. Chawan and R. Sunkara
Epidemiological studies have shown an inverse relationship between consumption of nutritive/non-nutritive foods of plant origin and colon cancer incidence. This study was conducted to determine the effect of green tea, phytic acid, and inositol at 2 g/100 ml levels singly and in combination on azoxymethane (AOM) induced colon tumors in Fisher 344 male rats. After an acclimatization period of one week, 8 groups of rats (15 rats each) were initially assigned to consume AIN 93G and later AIN 93M diet. All treatments were given in drinking water. All the rats received 16 mg/kg body mass AOM, two s/c injections at seven and eight week of age. Rats were killed at 46 week of age by CO2 euthanasia. Tumor incidence (percent) and tumors per tumor-bearing rat (TBR) in the control were significantly higher (P<0.05) than all treatment groups. Glutathione-S-transferase (GST) activity was significantly higher in treatment groups compared to control. These findings suggest that the additive effect of green tea, phytic acid and inositol may reduce the incidence of colon tumors, and can also be used as an adjuvant to chemomodulation.
Author: Rachel W. Li and Teresa D. Douglas and Geoffrey K. Maiyoh and Khosrow Adeli and Andre G. Theriault
The present study evaluated the effect of green tea (Camellia sinensis L.) leaf extract on triglyceride and glucose homeostasis in a fructose-fed hypertriglyceridemic, insulin-resistant hamster model. There was a significant decrease in plasma triglyceride levels following supplementation of the green tea epigallocatechin gallate-enriched extract (42% at 150 mg/(kg day) to 62% at 300 mg/(kg day) for 4 weeks). Compared to baseline, the fructose control group at the end of the study showed elevated serum insulin and apolipoprotein B levels, and decreased serum adiponectin levels. The fructose/green tea extract group showed a reversal in all of these metabolic defects, including an improvement in glucose levels during a glucose tolerance test. Triglyceride content was also examined in various tissues and compared to the control fructose group; supplementation of the green tea extract (300 mg/kg) reduced triglyceride content in liver and heart tissues. There was molecular evidence of improved lipid and glucose homeostasis based on peroxisome proliferator-activated receptor (PPAR) protein expression. Compared to the control fructose group, supplementation of the green tea extract (300 mg/kg) significantly increased PPARα and PPARγ protein expression. In summary, the data suggest that intake of the green tea extract ameliorated the fructose-induced hypertriglyceridemia and the insulin-resistant state in part through PPAR.
Author: T.D. Shanafelt and Y.K. Lee and T.G. Call and G.S. Nowakowski and D. Dingli and C.S. Zent and N.E. Kay
Green tea or its constituents have long been touted as a health promoting substance including claims it may have cancer prevention properties. We previously reported the in vitro ability of one tea polyphenol, epigallocatechin gallate (EGCG), to induce apoptotic cell death in the leukemic B-cells from a majority of patients with chronic lymphocytic leukemia (CLL). After the publication of our findings many patients with CLL and other low grade lymphomas began using over-the-counter products containing tea polyphenols despite the absence of evidence to suggest clinical benefit, definition of possible toxicities, or information on optimal dose and schedule. We have become aware of four patients with low grade B-cell malignancies seen in our clinical practice at Mayo Clinic who began, on their own initiative, oral ingestion of EGCG containing products and subsequently appeared to have an objective clinical response. Three of these four patients met criteria for partial response (PR) by standard response criteria. Although spontaneous remission/regression is occasionally observed in individuals with low grade B-cell malignancies, such events are rare. Several patients presented here had documented steady clinical, laboratory, and/or radiographic evidence of progression immediately prior to initiation of over-the-counter green tea products and then developed objective responses shortly after self-initiating this therapy. Such anecdotes highlight the need for clinical trials of tea polyphenols to define the optimal dosing, schedule, toxicities, and clinical efficacy before widespread use can be recommended. An NCI sponsored phase I/II trial of de-caffeinated green tea extracts for patients with asymptomatic, early stage CLL opened at Mayo Clinic in August 2005.