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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
Chemopreventive role of green tea in head and neck cancers
Author: Yoo Suk Kim and Chul-Ho Kim
In the era of personalized medicine, selecting the ideal treatment modality for head and neck cancer is becoming more complex. Also, despite the use of the newest agents, overall survival has not been improved notably over the past few decades. Currently, in accordance with the development of diagnostic tools, prevention and early detection of cancer are being emphasized more in obtaining better treatment outcomes. Among the various cancer preventative methods, the use of green tea is one of the most common approaches, and tea is known to be involved in multiple steps of carcinogenesis. Thus, in this short review, the protective roles of green tea components against the initiation, progression, and metastasis of head and neck malignancies will be discussed.
UHPLC determination of catechins for the quality control of green tea
Author: Marina Naldi and Jessica Fiori and Roberto Gotti and Aurélie Périat and Jean-Luc Veuthey and Davy Guillarme and Vincenza Andrisano
An ultra-high performance liquid chromatography (UHPLC) with UV detection method was developed for the fast quantitation of the most represented and biologically important green tea catechins and caffeine. UHPLC system was equipped with C18 analytical column (50 mm × 2.1 mm, 1.8 μm), utilizing a mobile phase composed of pH 2.5 triethanolamine phosphate buffer (0.1 M) and acetonitrile in a gradient elution mode; under these conditions six major catechins and caffeine were separated in a 3 min run. The method was fully validated in terms of precision, detection and quantification limits, linearity, accuracy, and it was applied to the identification and quantification of catechins and caffeine present in green tea infusions. In particular, commercially available green tea leaves samples of different geographical origin (Sencha, Ceylon Green and Lung Ching) were used for infusion preparations (water at 85 °C for 15 min). The selectivity of the developed UHPLC method was confirmed by comparison with UHPLC–MS/MS analysis. The recovery of the main six catechins and caffeine on the three analyzed commercial tea samples ranged from 94 to 108% (n = 3). Limits of detection (LOD) were comprised in the range 0.1–0.4 μg mL−1. An orthogonal micellar electrokinetic (MEKC) method was applied for comparative purposes on selectivity and quantitative data. The combined use of the results obtained by the two techniques allowed for a fast confirmation on quantitative characterization of commercial samples.
Effect of defined green tea extract in various dosage schemes on drug-metabolizing enzymes in mice in vivo
Author: Petra Matoušková and Hana Bártíková and Iva Boušová and Barbora Szotáková and Jan Martin and Jana Skorkovská and Veronika Hanušová and Veronika Tománková and Eva Anzenbacherová and Barbora Lišková and Pavel Anzenbacher and Lenka Skálová
Green tea represents a favourite beverage and green tea extracts are popular components of dietary supplements. The aim of present in vivo study was to report on the effect of defined green tea extract (Polyphenon) in various dosage schemes on drug-metabolizing enzymes in mice. The specific activities and expressions of a panel of drug-metabolizing enzymes (totally 16) were tested in liver and small intestine. Nine enzymes were significantly altered by Polyphenon treatment. The intestinal enzymes were more affected than the hepatic ones. The effects were mostly dose-dependent but short-term treatment had more pronounced impact than the long-term administration. Based on the results, normal consumption of green tea seems to be safe but extremely high doses of green tea extracts in dietary supplements could influence drugs metabolism and efficacy.
CAM use in dermatology. Is there a potential role for honey, green tea, and vitamin C?
Author: Naiara S. Barbosa and Amer N. Kalaaji
Complementary and alternative medicine (CAM) is a group of non-traditional medical practices that includes natural products, manipulations, and mind and body medicine. CAM use has grown and become popular among patients. In dermatology, honey, green tea, and vitamin C have been used as topical treatments for a variety of diseases. We performed a systematic review to explore the cutaneous effects of each of these three products. Honey's unique antibacterial, anti-inflammatory, and antioxidant properties were shown to contribute to wound healing, especially in ulcers and burns. Green tea, among many health benefits, demonstrated protection from ultraviolet-induced events, such as photoimmunosuppression and skin cancer growth. Vitamin C, known for its antioxidant properties and key role in collagen production, has been shown to produce positive effects on skin hyperpigmentation and aging. Future large well-designed clinical trials are needed in order to further investigate the potential of these agents as dermatological therapies.
Modeling and optimization of green tea precipitation for the recovery of catechins
Author: Miguel Monsanto and Nasim Hooshyar and Jan Meuldijk and Edwin Zondervan
Green tea catechins are claimed to have several health benefits (e.g. antioxidant, antimutagenic and antiviral) with increasing applications in the food and pharmaceutical markets. By using the tea creaming effect and by enhancing it, as a phase separation via precipitation, it is possible to recover a large amount of polyphenols from the cream phase without using toxic solvents. A design of experiments (DoE) together with statistical analysis allows a description of the system with polynomial models and enables the determination of the optimal conditions that maximize the catechins recovery, while minimizing the amount of caffeine, which is considered a contaminant. A total of four influence factors are studied in this DoE: hydroxypropylmethylcellulose and polyvinylpyrrolidone (used as precipitation agents), temperature and pH, of which only pH is found not to be significant. With the optimal combination of factors it is possible to separate and recover up to 67% of the catechins present in the green tea extract solution, while increasing the ratio of catechins/caffeine by 60%.
Effects of green tea and physical exercise on memory impairments associated with aging
Author: Maíra F. Flôres and Alexandre Martins and Helen L. Schimidt and Francielli W. Santos and Iván Izquierdo and Pâmela B. Mello-Carpes and Felipe P. Carpes
We investigated the effects of physical exercise and green tea supplementation (associated or not) on biochemical and behavioral parameters in the time course of normal aging. Male Wistar rats aged 9 months were divided into groups: control, physical exercise (treadmill running), and supplemented with green tea while either performing physical exercise or not. A young control group was also studied. Physical exercise and green tea supplementation lasted 3 months. Afterwards, behavioral and biochemical tests were performed. Biochemical measurements revealed differences in antioxidant and oxidant responses in hippocampus, prefrontal cortex and striatum. Behavioral testing showed age-related memory impairments reversed by physical exercise. The association of green tea supplementation and physical exercise did not provide aged rats with additional improvements in memory or brain oxidative markers. Green tea per se significantly decreased reactive oxygen species levels and improved antioxidant defenses although it did not reverse memory deficits associated with normal aging.
Effect of green tea extract and microwave pre-cooking on the formation of heterocyclic aromatic amines in fried chicken meat products
Author: G. Haskaraca and E. Demirok and N. Kolsarıcı and F. Öz and N. Özsaraç
Heterocyclic aromatic amines (HAAs) are mutagenic compounds formed naturally in meats after thermal processing and are classified as a probable human carcinogen. Also, mutagenic potency of HAAs is about 100-fold stronger than that of aflatoxin and 2000-fold stronger than that of benzo[a]pyrene. The aims of the present study were to investigate HAA contents and to determine HAA existence in coated chicken drumsticks (CDs) and coated chicken wings (CWs) which are frequently consumed in fast food chains after purchasing from fast food restaurants, and the effects of green tea extract added into the cover material and microwave-precooking for the mitigation and the formation of HAAs in CD and CW samples produced using a laboratory model. HAA (IQx, IQ, MeIQx, MeIQ, 7,8-DiMeIQx, 4,8-DiMeIQx, PhIP, AαC, MeAαC) analysis was done by HPLC after solid-phase extraction. MeIQx is the dominant HAA in all CD and CW samples obtained from fast food restaurants, and its level was found to vary between 0.22–33.73 and 11.22–62.83 ng/g, respectively. PhIP was detected in 5 out of 20 samples from fast food restaurants with a maximum level of 3.15 ng/g, and IQx, 7,8-DiMeIQx, AαC, and MeIQ were also detected. MeIQx values of CW and CD samples produced with the laboratory model varied between not detected and 1.45 and not detected and 2.32 ng/g, respectively, while IQ, MeIQ, 7.8 DiMeIQx, 4,8-DiMeIQx, AαC, and MeAαC were not detected in any of the CW or CD samples produced using the laboratory model. HAA contents of CD and CW samples obtained from fast food restaurants were higher than those of samples produced using the laboratory model due to the possible effect of uncontrolled frying conditions in restaurants. In addition, it was determined that the addition of green tea extract (GTE) and microwave pre-cooking (MC) did not present any detectable effect on reducing the formation of HAAs in fried CDs and CWs produced using a laboratory model under controlled frying conditions.
Dose-dependent functionality and toxicity of green tea polyphenols in experimental rodents
Author: Akira Murakami
A large number of physiologically functional foods are comprised of plant polyphenols. Their antioxidative activities have been intensively studied for a long period and proposed to be one of the major mechanisms of action accounting for their health promotional and disease preventive effects. Green tea polyphenols (GTPs) are considered to possess marked anti-oxidative properties and versatile beneficial functions, including anti-inflammation and cancer prevention. On the other hand, some investigators, including us, have uncovered their toxicity at high doses presumably due to pro-oxidative properties. For instance, both experimental animal studies and epidemiological surveys have demonstrated that GTPs may cause hepatotoxicity. We also recently showed that diets containing high doses (0.5-1%) of a GTP deteriorated dextran sodium sulfate (DSS)-induced intestinal inflammation and carcinogenesis. In addition, colitis mode mice fed a 1% GTP exhibited symptoms of nephrotoxicity, as indicated by marked elevation of serum creatinine level. This diet also increased thiobarbituric acid-reactive substances, a reliable marker of oxidative damage, in both kidneys and livers even in normal mice, while the expression levels of antioxidant enzymes and heat shock proteins (HSPs) were diminished in colitis and normal mice. Intriguingly, GTPs at 0.01% and 0.1% showed hepato-protective activities, i.e., they significantly suppressed DSS-increased serum aspartate aminotransferase and alanine aminotransferase levels. Moreover, those diets remarkably restored DSS-down-regulated expressions of heme oxygenase-1 and HSP70 in livers and kidneys. Taken together, while low and medium doses of GTPs are beneficial in colitis model mice, unwanted side-effects occasionally emerge with high doses. This dose-dependent functionality and toxicity of GTPs are in accordance with the concept of hormesis, in which mild, but not severe, stress activates defense systems for adaptation and survival.
Correlation between nitrogen application to tea flushes and quality of green and black teas
Author: Po-An Chen and Shu-Yen Lin and Chiou-Fang Liu and Yen-Shuo Su and Hun-Yuan Cheng and Jian-Hsing Shiau and Iou-Zen Chen
We treated the tea cultivar \{TTES\} No. 12 with different nitrogen fertilizers and prepared black and green teas from these tea flushes. Analyses of nitrogen content and levels of catechins and caffeine of shoots with two leaves and a bud were conducted to understand the influence of these factors on tea quality. Only the nitrogen content showed consistent effects on tea quality, whereas the effects of the other chemical components varied with season. A positive linear regression relationship was observed between nitrogen content of tea flushes and green tea quality, whereas a negative linear regression relationship was observed between nitrogen content and black tea quality. Thus, the quality of black and green teas could be determined based on the nitrogen content of the tea flushes.
Consequences of the matrix effect on recovery of dinotefuran and its metabolites in green tea during tandem mass spectrometry analysis
Author: Md. Musfiqur Rahman and A.M. Abd El-Aty and Jeong-Heui Choi and Sung-Woo Kim and Sung Chul Shin and Jae-Han Shim
Determining the residues of dinotefuran and its metabolites (MNG, UF, and DN) is highly problematic because of their polar characteristics. Additionally, tea contains many compounds that can interfere with residue analysis. Thus, the aim of the present study was to refine the extraction method that assures good recoveries for dinotefuran and its metabolites and removes most of the matrix components in green tea using liquid chromatography–tandem mass spectrometry (LC/MS/MS). We attempted to increase the extraction efficiency of the QuEChERS method by selecting the appropriate solvents among ethyl acetate, acetone, isopropanol, 25% methanol in acetonitrile, and methanol. We found that methanol was the best extraction solvent for dinotefuran and its polar metabolites in dry green tea samples; however, due to a limitation of an appropriate partitioning salt, acetonitrile was used as the extraction solvent. Matrix enhancement and suppression effects were observed for all analytes, which made the recovery rates variable. \{DN\} recovery was <70% when compared with matrix-matched calibration, whereas it was within the acceptable range (70–120%) when compared with solvent calibration. The opposite was observed for \{MNG\} and dinotefuran due to a matrix suppression effect. \{UF\} recovery was consistent in both matrix-matched and solvent calibrations despite having little suppressive effect. The method was successfully applied and dinotefuran and its metabolite residues were found in field-incurred green tea samples. The current findings suggest that using methanol as an appropriate QuEChERS solvent for problematic polar pesticides and investigating a suitable partitioning salt would considerably strengthen the practical impact of such data.