Research Database
The only comprehensive database for clinical and medical research papers on the healthy benefits of matcha/green tea
Recent Research Papers on
cancer-prevention
Author: Guoping Wang and Jianguo Hou and Liye Ma and Jiaxin Xie and Jianhua Yin and Danfeng Xu and Wenjun Chang and Xiaojie Tan and Tong Su and Hongwei Zhang and Guangwen Cao
Background: Risk factors for clear cell renal cell carcinoma (ccRCC) differ among populations and remain controversial. We carried out a hospital-based case–control study to examine the effects of health status, lifestyle, and some genetic polymorphisms on ccRCC risk in Chinese subjects. Methods: Between 2007 and 2009, 250 newly diagnosed, histologically confirmed ccRCC cases and 299 sex-, age-matched healthy controls provided complete information including consumption of tea and alcohol, smoking, occupational exposure, body mass index (BMI), hypertension, diabetes, and urolithiasis by face-to-face interview in Shanghai. Genetic polymorphisms of cytochrome P450 mono-oxygenase (CYP1A1: 6235T>C, 4889A>G, and 4887C>A), glutathione S-transferase (GSTP1: 342A>G), and N-acetyltransferase (NAT2: 481C>T, 590G>A, and 857G>A) were identified by PCR-RFLP and DNA sequencing. Adjusted odds ratio (AOR) and 95% confidence interval (CI) were derived through multivariate logistic regression. Results: Green tea intake (≥500 ml/d) was inversely associated with ccRCC risk, with an AOR of 0.34 (95% CI 0.21–0.55). BMI (≥25 kg/m2), hypertension, and urolithiasis were independently associated with an increased risk of ccRCC, with AOR (95% CI) of 2.10 (1.32–3.34), 2.49 (1.57–3.93), and 3.33 (1.12–9.89), respectively. No association was observed between smoking, alcohol consumption, or occupational exposure with ccRCC risk. The polymorphisms and their interactions with the environmental exposures were mostly not associated with ccRCC risk. Conclusion: BMI (≥25 kg/m2), hypertension, and urolithiasis are independently associated with an increased risk, whereas green tea intake (≥500 ml/d) is independently associated with a decreased risk of ccRCC. The polymorphisms of the xenobiotic-metabolizing enzymes are weakly associated with ccRCC risk in Chinese subjects.
Author: Mariana von Staszewski and Federico L. Jara and Ana L.T.G. Ruiz and Rosa J. Jagus and Joao E. Carvalho and Ana M.R. Pilosof
The development of milk functional foods including health-promoting green tea polyphenols represents a challenge for the food industry since the formation of protein–polyphenol complexes may affect both protein technological properties and polyphenols biological activity. The present work aimed at the characterization of complexes formed between green tea polyphenols and either β-lactoglobulin (β-lg) or caseinomacropeptide (CMP), as well as to evaluate how this complexation may impact on protein gelation and polyphenol antiproliferative activity against tumor cell lines. Particle size and charge of protein–polyphenol complexes depend on protein nature and pH. At pH 6 they had the smallest size and were soluble. The presence of polyphenols accelerated the gelation of both β-lg and CMP, and mainly affected viscoelasticity of β-lg gels. Polyphenol complexation by proteins did not inhibit its anti-proliferative activity. Moreover, they exerted a better performance on some particular tumor cell lines.
Author: Mi-Young Song and Shambhunath Bose and Ho-Jun Kim and Myeong-Jong Lee and Chi-Yeon Lim
Aim of the studyThe goal of this study was to evaluate the efficacy of mesotherapy treatment with Ephedra and green tea extract in combination on localized fat of overweight women subjects. Materials and methods Twenty-five overweight women, 20–35-years-of-age, body mass index ≥ 23 kg/m2 were randomly assigned into active (Ephedra + green tea, n = 13) and placebo (saline, n = 12) groups. A total eight herbal or saline mesotherapy administrations were performed into the thighs alternatively in two phases, each one comprising of four consecutive treatments on one thigh on weekly basis. Body composition parameters, circumference and subcutaneous fat area of thighs were measured before and after each phase, in addition to evaluating fasting free fatty acid (FFA) level of blood as well as adverse events of the therapy in volunteers. Results There were no significant changes in the body weight, BMI, body fat, and subcutaneous fat area of thigh within or between the groups, but the change in thigh circumference within the active group was significantly lower compared to that within the placebo group. The blood FFA level at 1 h after the first herbal therapy was significantly higher than that recorded at other time points of pre- and post-treatment measurements. Conclusions The herbal mesotherapy treatment produced a significant effect on thigh circumference and fasting-FFA level within the active group. Future studies that compensate for the limitations of this trial are required to fully ascertain the efficacy and safety of the proposed mesotherapy, and a very careful consideration is needed until then.
Author: Jianhui Hu and Yuqiong Chen and Dejiang Ni
Six Green tea powders (GTPs) were prepared from green tea with superfine grinding process. Their main quality components were determined by chemical methods and the scavenging effects of GTPs on ·OH and O2.− in vitro were evaluated by using deoxyribose assay and xanthine oxidase method, respectively. The results indicated that tea polyphenols and catechins contents decreased, while the contents of water-soluble carbohydrates in GTPs increased markedly, and no significant difference in amino acids and caffein with the decrease in particle size during superfine grinding, which benefited to reduce bitterness and preserve briskness of GTPs. Meanwhile, superfine grinding increased extraction of TPS markedly, which could lead to more potent scavenging capacity of GTPEs on ·OH. Based on the above analysis, it suggested that superfine grinding time should be controlled within 30–50 min, with ideal parameters of GTP: X: 4.93–4.75%, d50: 20.3–13.5 μm, ρbulk: 0.323–0.297 kg/m3, ρtapped: 0.666–0.614 kg/m3. Under this condition, we could prepare GTP with green and bright color, narrower and more uniform particle size distribution, as well as possessing more food processing property.
Author: E.E. Mehana and Abdel Raheim M.A. Meki and Khalid Majid Fazili
In the present study, the effect of green tea extract (GTE) on lead induced toxicity was studied in Sprague–Dawley rats. Four groups of rats were used in the study. Lead and GTE was given orally to the rats with drinking water for 8 weeks. Lead concentration in the digested tissues of liver was detected using atomic absorption spectroscopy. The activities of glutathione-S-transferase (GST) and superoxide dismutase (SOD) were used as markers to evaluate the anti oxidant status of tissues. Lead exposure was found to attenuate the antioxidant potential of liver, which was however augmented when supplemented with green tea extract. Liver enzymes ALT, AST and ALP and serum protein determinations indicated the protective effects of green tea extract. Histopathological studies of liver revealed that supplementation of green tea extract resulted in mild degeneration and congestion of the blood vessels and an enhanced regenerative capacity.
Author: Quan V. Vuong and Sing P. Tan and Costas E. Stathopoulos and Paul D. Roach
The green tea (Camellia sinensis) catechins are strong antioxidants linked with potential health benefits. Based on previous studies, it was hypothesised that the typical household conditions for brewing green tea in a teabag – 200 mL freshly boiled water for 2–3 min, as per the manufacturers’ instructions – were not sufficient to extract all the catechins and that a household microwave oven could be used to improve the extraction. The catechins and the two other main green tea components, caffeine and theanine, were monitored by HPLC. The typical household conditions only extracted 62% (61 mg/g tea), 76% (24 mg/g) and 80% (10 mg/g) of the catechins, caffeine and theanine, respectively, from the five varieties of teabags analysed. However, using microwave assisted extraction (MAE) by first brewing a teabag in 200 mL freshly boiled water for 0.5 min before irradiation for 1 min in a microwave oven (hot MAE), improved the extraction of the catechins and caffeine to 80% (80 mg/g) and 92% (29 mg/g), respectively, although the extraction of theanine was not affected. Therefore, the hot MAE technique could help maximise the extraction of the catechins for those who consume green tea for the potential health benefits of the catechins.
Author: Susanne M. Henning and Piwen Wang and Jonathan Said and Clara Magyar and Brandon Castor and Ngan Doan and Carmen Tosity and Aune Moro and Kun Gao and Luyi Li and David Heber
It has been demonstrated in various animal models that the oral administration of green tea (GT) extracts in drinking water can inhibit tumor growth, but the effects of brewed GT on factors promoting tumor growth, including oxidant damage of DNA and protein, angiogenesis and DNA methylation, have not been tested in an animal model. To explore these potential mechanisms, brewed GT was administered instead of drinking water to male severe combined immunodeficiency (SCID) mice with androgen-dependent human LAPC4 prostate cancer cell subcutaneous xenografts. Tumor volume was decreased significantly in mice consuming GT, and tumor size was significantly correlated with GT polyphenol (GTP) content in tumor tissue. There was a significant reduction in hypoxia-inducible factor 1-alpha and vascular endothelial growth factor protein expression. GT consumption significantly reduced oxidative DNA and protein damage in tumor tissue as determined by 8-hydroxydeoxyguanosine/deoxyguanosine ratio and protein carbonyl assay, respectively. Methylation is known to inhibit antioxidative enzymes such as glutathione S-transferase pi to permit reactive oxygen species promotion of tumor growth. GT inhibited tumor 5-cytosine DNA methyltransferase 1 mRNA and protein expression significantly, which may contribute to the inhibition of tumor growth by reactivation of antioxidative enzymes. This study advances our understanding of tumor growth inhibition by brewed GT in an animal model by demonstrating tissue localization of GTPs in correlation with inhibition of tumor growth. Our results suggest that the inhibition of tumor growth is due to GTP-mediated inhibition of oxidative stress and angiogenesis in the LAPC4 xenograft prostate tumor in SCID mice.
Author: Dominique Trudel and David P. Labbé and Isabelle Bairati and Vincent Fradet and Laurent Bazinet and Bernard Têtu
Objective This systematic review was conducted to examine the effects of green tea or green tea components on the prevention and progression of epithelial ovarian cancer. Methods Using Medline, EMBASE and SciVerse (last researched: July 2011), we retrieved 22 articles including 5 epidemiological studies. Results In epithelial ovarian cancer cell lines, green tea and green tea components have been shown to downregulate the expression of proteins involved in inflammation, cell signalization, cell motility and angiogenesis. Green tea and green tea components would induce apoptosis and could potentiate the effects of cisplatin, a chemotherapeutic agent. In human observational studies, significant associations between green tea intake and both decreased ovarian cancer occurrence and better prognosis were reported. Conclusions Available literature suggests potential molecular targets for green tea in ovarian cancer treatment and also provides data supporting the clinical evaluation of the role of green tea or green tea components in ovarian cancer prevention and treatment.
Author: Martina Bancirova
The antioxidant properties of black and green teas are well known. It is also possible to determine their antioxidant capacity by using a chemiluminscent method. This method is based on the measurement of the delay in the emission of light from the luminol reaction in the presence of the antioxidant. Bloodstains which are invisible to the naked eye can also be detected by luminol. Three common methods (detection using the Grodsky or Weber formulations and by Bluestar® Forensic latent bloodstain reagent) are based on the luminol chemiluminescence reaction. The bloodstains can be masked by drinks and/or foods containing antioxidants. The aim of this work was to compare the ability of black and green teas containing antioxidants to cause false negative results during chemiluminescent bloodstain detection.
Author: Quansheng Chen and Zhiming Guo and Jiewen Zhao and Qin Ouyang
To rapidly and efficiently measure antioxidant activity (AA) in green tea, near infrared (NIR) spectroscopy was employed with the help of a regression tool in this work. Three different linear and nonlinear regressions tools (i.e. partial least squares (PLS), back propagation artificial neural network (BP-ANN), and support vector machine regression (SVMR)), were systemically studied and compared in developing the model. The model was optimized by a leave-one-out cross-validation, and its performance was tested according to root mean square error of prediction (RMSEP) and correlation coefficient (Rp) in the prediction set. Experimental results showed that the performance of SVMR model was superior to the others, and the optimum results of the SVMR model were achieved as follow: RMSEP = 0.02161 and Rp = 0.9691 in the prediction set. The overall results sufficiently demonstrate that the spectroscopy coupled with the SVMR regression tool has the potential to measure AA in green tea.
Other Popular Research Topics
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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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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