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

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

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

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

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

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.

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Most Recent Research Articles

Memory deficits and oxidative stress in cerebral ischemia–reperfusion: Neuroprotective role of physical exercise and green tea supplementation

Author: Helen L. Schimidt and Aline Vieira and Caroline Altermann and Alexandre Martins and Priscila Sosa and Francielli W. Santos and Pâmela B. Mello-Carpes and Ivan Izquierdo and Felipe P. Carpes

Ischemic stroke is a major cause of morbidity and mortality all over the world. Among impairments observed in survivors there is a significant cognitive learning and memory deficit. Neuroprotective strategies are being investigated to minimize such deficits after an ischemia event. Here we investigated the neuroprotective potential of physical exercise and green tea in an animal model of ischemia–reperfusion. Eighty male rats were divided in 8 groups and submitted to either transient brain ischemia–reperfusion or a sham surgery after 8 weeks of physical exercise and/or green tea supplementation. Ischemia–reperfusion was performed by bilateral occlusion of the common carotid arteries during 30 min. Later, their memory was evaluated in an aversive and in a non-aversive task, and hippocampus and prefrontal cortex were removed for biochemical analyses of possible oxidative stress effects. Ischemia–reperfusion impaired learning and memory. Reactive oxygen species were increased in the hippocampus and prefrontal cortex. Eight weeks of physical exercise and/or green tea supplementation before the ischemia–reperfusion event showed a neuroprotective effect; both treatments in separate or together reduced the cognitive deficits and were able to maintain the functional levels of antioxidant enzymes and glutathione.

 

 

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Green tea and type 2 diabetes

Author: Jae-Hyung Park and Jae-Hoon Bae and Sung-Soon Im and Dae-Kyu Song

Green tea and coffee consumption have been widely popular worldwide. These beverages contain caffeine to activate the central nervous system by adenosine receptor blockade, and due to the caffeine, addiction or tolerance may occur. In addition to this caffeine effect, green tea and coffee consumption have always been at the center of discussions about human health, disease, and longevity. In particular, green tea catechins are involved in many biological activities such as antioxidation and modulation of various cellular lipid and proteins. Thus, they are beneficial against degenerative diseases, including obesity, cancer, cardiovascular diseases, and various inflammatory diseases. Some reports also suggest that daily consumption of tea catechins may help in controlling type 2 diabetes. However, other studies have reported that chronic consumption of green tea may result in hepatic failure, neuronal damage, and exacerbation of diabetes, suggesting that interindividual variations in the green tea effect are large. This review will focus on the effect of green tea catechins extracted from the Camellia sinensis plant on type 2 diabetes and obesity, and the possible mechanistic explanation for the experimental results mainly from our laboratory. It is hoped that green tea can be consumed in a suitable manner as a supplement to prevent the development of type 2 diabetes and obesity.

 

 

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Development of liquid chromatography–tandem mass spectrometry method for analysis of polyphenolic compounds in liquid samples of grape juice, green tea and coffee

Author: Yelena Sapozhnikova

A simple and fast method for the analysis of a wide range of polyphenolic compounds in juice, tea, and coffee samples was developed using liquid chromatography–tandem mass spectrometry (LC–MS/MS). The method was based on a simple sample preparation “dilute and shoot” approach, and LC–MS/MS quantification using genistein-d4 as an internal standard. The performance of six different syringeless filter devices was tested for sample preparation. The method was evaluated for recoveries of polyphenols at three spiking levels in juice, tea, and coffee samples. The recoveries of the majority of polyphenols were satisfactory (70–120%), but some varied significantly (20–138%) depending on the matrix. NIST Standard Reference Materials (SRM) 3257 Catechin Calibration Solutions and 3255 Camellia sinensis (Green Tea) Extract with certified concentrations of catechin and epicatechin were used for method validation. The measurement accuracy in two SRMs was 71–113%. The method was successfully applied to the analysis of liquid samples of grape juice, green tea, and coffee.

 

 

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Selenium enriched green tea increase stability of Lactobacillus casei and Lactobacillus plantarum in chitosan coated alginate microcapsules during exposure to simulated gastrointestinal and refrigerated conditions

Author: Dan Cristian Vodnar and Carmen Socaciu

The effects of selenium enriched green tea (SGT; 85.8–96 mg/kg) in different concentrations of 1 g and 2 g/100 mL, on the in vitro exposure to simulated gastrointestinal juice and refrigerated storage of encapsulated Lactobacillus casei and Lactobacillus plantarum were investigated in chitosan coated alginate beads. The encapsulation yield of viable cells in chitosan coated alginate beads with and without SGT was not significantly different (P < 0.05). These results together with the study about the survival of probiotic bacteria in microspheres with SGT during storage at 4 °C, demonstrated significantly higher number (P < 0.05) of survival bacteria in microcapsules with SGT 2 g/100 mL. Microencapsulated L. casei and L. plantarum with SGT 1 g and 2 g/100 mL were resistant to simulated gastric conditions (pH 2.0, 2 h) and bile solution (3 g/100 mL, 2 h) resulting in significantly (P < 0.05) improved survival when compared with microencapsulation without SGT addition.

 

 

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Orthogonal analytical methods for botanical standardization: Determination of green tea catechins by qNMR and LC–MS/MS

Author: José G. Napolitano and Tanja Gödecke and David C. Lankin and Birgit U. Jaki and James B. McAlpine and Shao-Nong Chen and Guido F. Pauli

The development of analytical methods for parallel characterization of multiple phytoconstituents is essential to advance the quality control of herbal products. While chemical standardization is commonly carried out by targeted analysis using gas or liquid chromatography-based methods, more universal approaches based on quantitative 1H NMR (qHNMR) measurements are being used increasingly in the multi-targeted assessment of these complex mixtures. The present study describes the development of a 1D qHNMR-based method for simultaneous identification and quantification of green tea constituents. This approach utilizes computer-assisted 1H iterative Full Spin Analysis (HiFSA) and enables rapid profiling of seven catechins in commercial green tea extracts. The qHNMR results were cross-validated against quantitative profiles obtained with an orthogonal LC–MS/MS method. The relative strengths and weaknesses of both approaches are discussed, with special emphasis on the role of identical reference standards in qualitative and quantitative analyses.

 

 

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Survival and metabolic activity of probiotic bacteria in green tea

Author: A.M. López de Lacey and E. Pérez-Santín and M.E. López-Caballero and P. Montero

The aim of this study was to determine the enzymatic activity and survival of three probiotic strains (Lactobacillus paracasei LAFTI-L26, Lactobacillus acidophilus LAFTI-L10 and Bifidobacterium animalis ssp. lactis LAFTI-B94) during incubation in six different varieties of green tea extracts. The polyphenol content, antioxidant, antimicrobial and antihypertensive properties in green tea (variety Wu Lu Mountain) and in two standards (epigallocatechin-3-gallate and rutin) were also investigated before and after incubation with B. animalis B94. The green tea extracts permitted the survival of the selected probiotic strains better than the saline solution, with B. animalis B94 maintaining the highest levels of viable cells. These selected probiotic bacteria exhibited β-glucosidase, β-galactosidase and α-rhamnosidase activity. The antioxidant and antihypertensive properties of standard solutions of epigallocatechin-3-gallate and rutin increased after incubation with B. animalis B94, caused by polyphenol content reduction and the formation of other more highly biologically active metabolites. However, during the incubation of green tea with B. animalis B94, changes in the concentration of the most abundant green tea polyphenols did not enhance the biological activity.

 

 

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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.

 

 

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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.

 

 

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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.

 

 

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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%.

 

 

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