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: Gema Morales and Maribel Jimenez and Oscar Garcia and María Remedios Mendoza and Cesar Ignacio Beristain
The objective of the present work was to evaluate the effect of natural extracts on the formation of acrylamide in fried potatoes. The aqueous extracts used were obtained from wild oregano (Origanum vulgare), thyme (Thymus vulgaris), cinnamon (Cinnamomum verum), bougainvillea (Bougainvillea spp) and green tea (Camellia sinensis), which presented a high percentage of free radical inhibition (DPPH) (48–99%) and content of total phenolic compounds (205–547 μg EAG/μg of d.w.). Potatoes were submerged in the antioxidant extracts at a concentration of 1 g/L for 1 min, before being fried and their acrylamide concentration quantified by GC–MS. The extracts from green tea, cinnamon and oregano reduced the acrylamide level by 62%, 39% and 17%, respectively. The potatoes submerged in cinnamon and bougainvillea extracts showed differences in the color parameters compared to the control potatoes (P < 0.05); however, no significant differences (P > 0.05) were found in the texture and the peroxide values. The sensorial evaluation showed that the acceptance of the potatoes was not affected by the treatment applied. Thus, we can conclude that pre-treating potatoes with antioxidants before frying produces beneficial effects such as a reduction in acrylamide content, without any significant changes in their physicochemical, sensorial and textural properties.
Author: Georgia Soultani and Vasiliki Evageliou and Antonios E. Koutelidakis and Maria Kapsokefalou and Michael Komaitis
The effect of pectin on the antioxidant capacity and phenolic content of black, green, mountain tea and Pelargonium purpureum infusions was investigated. Antioxidant capacity was determined by the Ferric Reducing Antioxidant Power (FRAP) assay and total phenolics by the Folin-Ciocalteu method. Green tea was the richest in phenolics and had the highest antioxidant capacity, followed by black and the remaining two infusions. High methoxy pectin, added at various concentrations, did not affect the studied properties of all the infusions. As a further step, milk, lemon juice or sugars (sucrose, fructose) were added to black and green tea infusions, in the presence and absence of pectin. For green tea infusions, no significant differences were reported for the studied properties, for all the constituents, both in the presence and absence of pectin. For black tea infusions statistically different values were observed when pectin was combined with the constituents. These results suggest that pectin does not mask the antioxidant capacity of tea infusions and therefore, it may be added to tea infusions for stabilizing or thickening reasons and create new food formulations with improved health benefits.
Author: M.W. Korir and F.N. Wachira and J.K. Wanyoko and R.M. Ngure and R. Khalid
Several studies have demonstrated that tea flavonoids protect cells and tissues against free radicals which have been implicated in the etiology of oxidative stress-related disease disorders. However, black tea is commonly consumed with additives that could otherwise affect the bioavailability of the active tea molecules. In this study, the biochemical parameters of Kenyan teas were determined and the effect of added milk and sweeteners on the antioxidant activity of Kenyan teas was investigated. The effect of tea antioxidants on glutathione (GSH) was also evaluated in vivo in a time series study using Swiss mice. Green teas had the highest levels of total polyphenols, total and individual catechins, while black teas had high levels of total thearubigins, total theaflavins and theaflavin fractions. The antioxidant activity was high in green teas though some of the black teas were as efficacious as the green teas. The addition of milk, sugar and honey significantly (p < 0.05) decreased the antioxidant activity of tea in a concentration-dependent manner. Addition of the sweetener, stevia (Stevia rebaudiana Bertoni), showed no significant (p > 0.05) influence on the antioxidant activity of tea and therefore can be recommended as a preferred sweetener for tea. Significantly (p < 0.001) higher levels of GSH were observed in plasma than in other tissues. GSH levels were generally highest 2 h after tea consumption, which indicates the need to repeatedly take tea every 2 h to maximise its potential health benefits.
Author: Ana-Maria Manea and Bogdan Stefan Vasile and Aurelia Meghea
In this paper, the preparation and characterization of some novel nanostructured lipid carriers for drug delivery are reported. They are obtained by mixing two solid lipids, cetyl palmitate and glyceryl stearate, with three types of vegetable oils: grape seed oil, St. John's wort oil (Hypericum perforatum oil) and sea buckthorn oil. In order to increase their antioxidant and antimicrobial properties, they are co-loaded with green tea extract by using a modified high shear homogenization technique. Size distribution and polydispersity index of the developed nanostructured lipid carriers determined by the dynamic light scattering, and corroborated with the results obtained by the transmission electron microscopy analysis, confirmed that the structures obtained are at nanoscales. The crystallinity behavior of the prepared nanostructured lipid carriers has been studied by differential scanning calorimetry; zeta potential measurements show that all loaded nanostructures present excellent physical stability. Their antioxidant and antimicrobial properties evaluated by an appropriate in vitro analysis using the chemiluminescence method, and the diffusion disc method, respectively, show that green tea extract could be utilized as a valuable natural source of antioxidant and antimicrobial agent. These new nano-formulations proved to have significant potential for nutritional and pharmaceutical applications.
Author: Mariana von Staszewski and Victor M. Pizones Ruiz-Henestrosa and Ana M.R. Pilosof
Green tea polyphenols have a good antioxidant capacity but poor interfacial activity. β-lactoglobulin (β-lg) was used as an emulsifier agent and also as a carrier molecule by spontaneous nanocomplexes formation with green tea polyphenols. Oil-in-water emulsions containing liver fish oil rich in ω-3 fatty acids were formulated using these nanocomplexes at pH 6. The interfacial behavior of these complexes showed that both surface pressure and dilatational properties decreased as compared with pure β-lg. However, the initial droplet size and stability of emulsions were improved in the presence of the nanocomplexes. Moreover, the oxidative stability of liver fish oil was improved by the presence of polyphenols.
Author: Yong-Quan Xu and Gen-Sheng Chen and Qi-Zhen Du and Fei Que and Hai-Bo Yuan and Jun-Feng Yin
The formation and the main chemical components of sediments, including reversible tea sediments (RTS) and irreversible tea sediments (IRS), in concentrated green tea during low-temperature storage were studied. RTS was mainly formed in the first 10 days, and IRS was mainly formed between 20 and 40 days of storage. The RTS were the primary sediment, contributing more than 90% of the total sediment. The RTS comprised of polyphenols, total sugar, caffeine, flavones and proteins, while the IRS mainly comprised of oxalates of Ca, Mg, Ga and Mn. The total mineral content in the IRS (17.1%) was much higher than that in the RTS (2.6%) after 80 days of storage. The Ca, Mg, Mn and Ga contents in IRS were over 1.0% (w/w) each. About 75% of the IRS was soluble in 0.1 M aqueous HCl, with the oxalate accounting for 68%. Minerals and oxalic acid were the crucial factors in the IRS formation.
Author: Asta Spadiene and Nijole Savickiene and Liudas Ivanauskas and Valdas Jakstas and Andrejs Skesters and Alise Silova and Hiliaras Rodovicius
The prevalence of diabetes mellitus (DM) has dramatically increased in the past decade. Furthermore, increasing evidence from research shows that oxidative stress (OS) plays a crucial role in the pathogenesis of diabetes and in its complications. A search for ways to reduce oxidative damage has become the focus of interest for the majority of scientists. In this study, we determined the radical scavenging activity of single green tea constituents by using an on-line high performance liquid chromatography (HPLC)–2,2-diphenyl-1-picrylhydrazyl (DPPH) method and evaluated the antioxidant effects on type 2 diabetic patients by performing a double-blind, placebo-controlled study. Epigallocatechin gallate was identified as the most potent antioxidant, contributing approximately 50% of the total antioxidant capacity of green tea extract. We also found a statistically significant decrement of lipid peroxidation markers in patients treated with green tea extract after 9 months or after 18 months of follow-up. Overall, these findings are attractive for diabetic patients, helping them to keep a high level of performance and well-being, which ultimately may delay the time of disability and reduce mortality.
Author: Jun Xi and Lianggong Yan and Lang He
The main aim of this work was to model the extraction process of the major green tea constituents in order to quantify the influence of the pressure on extraction kinetics. The kinetics of solid–liquid extraction of total catechins and caffeine at several pressures (200, 300, 400 and 500 MPa) were carried out using 50% aqueous ethanol. So and Macdonald’s model involving the concept of broken and intact cells in order to describe three successive extraction periods: an initial very fast washing stage, a fast diffusion stage and a slow diffusion stage, was successfully developed for describing the mechanism of solid–liquid extraction of the major green tea constituents under different pressures. From the modeling results, the influence of the pressure on the extraction yields of total catechins and caffeine of the various stages at equilibrium, and the mass transfer coefficient were identified.
Author: I. Onakpoya and E. Spencer and C. Heneghan and M. Thompson
Introduction Many different dietary supplements are currently marketed for the management of hypertension, but the evidence for effectiveness is mixed. The aim of this systematic review was to evaluate the evidence for or against the effectiveness of green tea (Camellia sinensis) on blood pressure and lipid parameters. Methods and results Electronic searches were conducted in Medline, Embase, Amed, Cinahl and the Cochrane Library to identify relevant human randomized clinical trials (RCTs). Hand searches of bibliographies were also conducted. The reporting quality of included studies was assessed using a checklist adapted from the CONSORT Statement. Two reviewers independently determined eligibility, assessed the reporting quality of the included studies, and extracted the data. As many as 474 citations were identified and 20 RCTs comprising 1536 participants were included. There were variations in the designs of the RCTs. A meta-analysis revealed a significant reduction in systolic blood pressure favouring green tea (MD: −1.94 mmHg; 95% CI: −2.95 to −0.93; I2 = 8%; p = 0.0002). Similar results were also observed for total cholesterol (MD: −0.13 mmol/l; 95% CI: −0.2 to −0.07; I2 = 8%; p < 0.0001) and LDL cholesterol (MD: −0.19 mmol/l; 95% CI: −0.3 to −0.09; I2 = 70%; p = 0.0004). Adverse events included rash, elevated blood pressure, and abdominal discomfort. Conclusion Green tea intake results in significant reductions in systolic blood pressure, total cholesterol, and LDL cholesterol. The effect size on systolic blood pressure is small, but the effects on total and LDL cholesterol appear moderate. Longer-term independent clinical trials evaluating the effects of green tea are warranted.
Author: Soon-Kil Cho and A.M. Abd El-Aty and Md. Musfiqur Rahman and Jeong-Heui Choi and Jae-Han Shim
A method for determining eight pesticide (cyhalothrin, flufenoxuron, fenitrothion, EPN, bifenthrin, difenoconazole, triflumizole, and azoxystrobin) residues in made green tea as well as a tea infusion (under various brewing water temperatures; 60, 80, and 100°C) using gas chromatography (GC) micro-electron capture detector (μECD) was developed and validated. The extraction method adopted the relatively commonly used approach of solid sample hydration, with the green tea hydrated before being extracted through salting out with acetonitrile followed by a cleanup procedure. The analytes were confirmed using GC-coupled to tandem mass spectrometry (GC/MS/MS) with a triple quadrupole. The linearity of the calibration curves yielded determination coefficients (R2)>0.995. Recoveries were carried out using blank samples spiked with all analytes at two levels. The results demonstrated that all pesticides were recovered within the range of 77–116% with a relative standard deviation (RSD) ⩽14%. The quantification limits of 0.015–0.03 mg/kg were lower than the maximum residue limits (MRLs) set by the Korea Food and Drug Administration (KFDA) for all analytes (0.05–10 mg/kg). The infusion study indicated that cyhalothrin, flufenoxuron, and bifenthrin did not infuse into the tea brew from the made tea. Increases in brewing time resulted in increased transfer of azoxystrobin, fenitrothion, and difenoconazole from the made tea to the brew; however, this was not the case with triflumizole or EPN. We conclude that transfer of pesticides appeared to be dependent on their water solubilities and drinking a cup of tea is recommended to be at a water temperature of 60°C.