Cups Of Green Tea Research Articles

Green tea and coffee consumption and risk of kidney cancer in Japanese adults

The study aimed to evaluate the association between green tea and coffee consumption and the risk of kidney cancer using data from a large prospective cohort study in Japan (the Japan Public Health Center-based Prospective Study: JPHC Study). A total of 102,463 participants aged 40–69 were followed during 1,916,421 person-years (mean follow-up period, 19 years). A total of 286 cases of kidney cancer (199 in men, 87 in women) were identified. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) while adjusting for potential confounders. No statistically significant association between green tea intake and kidney cancer risk was found in the total population. Among women who consumed more than five cups of green tea per day, a statistically significant decreased risk was shown with a HR of 0.45 (95% CI: 0.23–0.89), compared to women who rarely consumed green tea. For coffee consumption, the association of kidney cancer risk was not statistically significant. This large prospective cohort study indicated green tea intake may be inversely associated with kidney cancer risk in Japanese adults, particularly in Japanese women.

Association between tea intake and hospitalized nephrolithiasis in Chinese adults: A case-control study.

Introduction and aimNephrolithiasis is one of the most common urological disorders worldwide. Tea is one of the most popular drinks worldwide. This study aimed to explore the association between tea intake and hospitalized nephrolithiasis in Chinese adults.MethodsThe patients and healthy participants were from the Shenyang sub-cohort of Tianjin Chronic Low-Grade Systemic Inflammation and Health Cohort Study. After selecting and matching by age (±1 year) and sex using the 1:2 ratio, 834 participants were included in this study. Of these, 278 patients had hospitalized nephrolithiasis and 556 were healthy controls. The tea intake was assessed using a validated self-administered food frequency questionnaire. Multivariate conditional logistic regression analysis was used to evaluate the association between tea intake and hospitalized nephrolithiasis.ResultsAfter adjustment, a higher frequency of tea intake was found to be negatively associated with the risk of hospitalized nephrolithiasis. Compared with participants who never drank tea, the odds ratio (95% confidence interval) [OR (95% CI)] for participants who drank ≥1 cup (180 mL) of tea per day was 0.418 (0.192–0.911) (P for trend = 0.013). Moreover, the adjusted OR (95% CI) for participants who drank ≥1 cup of green tea and black tea per day was 0.189 (0.069–0.520) (P for trend <0.001) and 1.248 (0.437–3.559) (P for trend = 0.654), respectively.ConclusionsIncreased tea intake was found to be associated with a lower risk of hospitalized nephrolithiasis among Chinese adults. This finding may assist in the prevention of hospitalized nephrolithiasis.

Effect of low caffeine doses on jumping performance: a meta-analysis

PurposeThe purpose of this paper is to explore the effects of low doses of caffeine (<3 mg/kg) on jumping performance using a meta-analysis.Design/methodology/approachThe search for eligible studies was performed through six databases, with additional backward and forward citation tracking. A random-effects meta-analysis was performed to compare the effects of caffeine vs placebo on jump height. The methodological quality of the included studies was appraised using the physiotherapy evidence database checklist.FindingsEight studies were included in the review. They were classified as good or excellent methodological quality. The pooled number of participants across all studies was 203. Four studies provided caffeine in relative doses, ranging from 1 to 2 mg/kg. Four studies provided caffeine supplementation in absolute doses of 80, 150 or 200 mg. The meta-analysis found that caffeine ingestion increased vertical jump height (Cohen’s d: 0.21; 95% confidence interval: 0.10, 0.31; p < 0.001; +3.5%).Originality/valueThe present meta-analysis found that caffeine doses of ∼1 to 2 mg/kg enhance jumping height. The effects observed herein are similar to those with higher caffeine doses, which is relevant as low caffeine doses produce minimal side effects. For most individuals, a caffeine dose of ∼1 to 2 mg/kg is equivalent to an amount of caffeine in an energy drink, one to two cups of coffee, one to two pieces of caffeinated chewing gum or several cups of green tea.

Coffee of the Gods

Coffee of the Gods Nay Win Myint (bio) Translated from Burmese by Patrick McCormick 1 Sour Plum Hill was a small village, and as the name implied, overgrown with sour plums. A little over four miles away, the nearest village, Kyaungzu, was larger, hot and dry, covered in dust—distant, poor, with only a few houses: nothing special. When people wanted something like a special snack to tide them over when keeping the precepts on a holy day, or some other kind of ready-to-eat food, it was Kyaungzu they went to. Sour Plum had only a market. Still, it was a proper village, with a bicycle repair and barber's chair. Some villagers grew sugarcane, so there was a small cane-juice stall. You could get a cup of brick-red syrupy tea, strong and sweet, at the small teashop. Over to the west, a little stall sold vegetable fritters, and another toddy wine. That was pretty much it. Visitors could get a haircut, have their bicycles repaired, and for two kyats, have as much cane juice as they wanted. They could go to Ko Loun's shack in the palm grove for toddy wine, and to I Kun's teashop for tea. What I want to tell you about now is I Kun's teashop. More precisely, the small packets of coffee powder sitting on the upper left-hand corner of the table where he mixed up the tea. 2 I Kun had bought those powdered coffee packets a good while ago; he couldn't remember exactly when. So long ago that, would you believe, there'd been only one customer for coffee in Sour Plum Hill. That was Chan Htun Aung: tall yet stooped, flat-lipped, with an unkempt beard and stubborn demeanor. He'd go to I Kun's every morning for a cup. If anyone loved his coffee, it was him. He'd swallow it down in one long gulp and then puff on a Two Elephants cheroot before pouring a little green tea into the blackish dregs at the bottom of the cup and drink that. Then, he'd puff away on his cheroot, have two cups of green tea, let out a resounding belch, get up, and be off. In the evenings, the teashop closed up early, so before going home, he'd return to get another cup of coffee and let it sit. Just before bed, he'd drink it, weak and cold. He could go to bed only after having had a taste of coffee. The problem was that I Kun's shop was no grand establishment. Keep in [End Page 221] mind that it was the kind of place that, to make a sign for it, he had just dipped his finger into enamel paint and written the name out on a sheet of zinc. Nor were the villagers the kind of people to sit in teashops as was done in the towns. A cup of tea cost nothing, but no one settled down for any length of time. The question then was, just whom did I Kun sell to? The horse-cart drivers crossing back and forth while the market was open would stop and have tea. Workers from the irrigation canal would too. Sometimes when villagers had a little extra money, they'd have a cup, or when they had guests, they might come get some. That was all who came. It was the kind of teashop that sold less than thirty cups a day. That wasn't all he sold, however—he also had dusty bottles of soda water, ginger beer, and Wincarnis for sale. That's how he made his living, selling odds and ends. Like I said, it was thirty cups of tea a day, but only one cup of coffee, which was for Chan Htun Aung. The packets of coffee powder I Kun got whenever he went to Kyaungzu to buy stock for his store in bulk were only for him. Sometimes the packets went moldy and even the flavor would go, making it hard to still call the contents "powdered coffee," except for the memory of what they had once been. But...

Drinking Green Tea: Despite the Risks Due to Mycotoxins, Is It Possible to Increase the Associated Health Benefits?

Tea has been consumed for thousands of years. Despite the different varieties, particular emphasis has been placed on green tea (GT), considering the associated health benefits following its regular consumption, some of which are due to its polyphenol constituents, such as epigallocatechin-3-gallate (EGCG). Tea is not prone to the growth of microorganisms, except fungus, when proper storage, handling, and packing conditions are compromised. Consequently, mycotoxins, secondary metabolites of fungi, could contaminate tea samples, affecting human health. In the present study, we aimed to assess the balance between risks (due to mycotoxins and high levels of EGCG) and benefits (due to moderate intake of EGCG) associated with the consumption of GT. For this, 20 GT samples (10 in bulk and 10 in bags) available in different markets in Lisbon were analyzed through a LC–MS/MS method, evaluating 38 different mycotoxins. Six samples revealed detectable values of the considered toxins. Current levels of mycotoxins and EGCG intake were not associated with health concerns. Scenarios considering an increasing consumption of GT in Portugal showed that drinking up to seven cups of GT per day should maximize the associated health benefits. The present study contributes to the future establishment of GT consumption recommendations in Portugal.

Trapping Acrolein by Theophylline/Caffeine and Their Metabolites from Green Tea and Coffee in Mice and Humans.

Acrolein (ACR) is found exogenously as a widespread environmental pollutant and endogenously, where it is thought to be involved as a pathogenic factor in the progression of many pathological conditions. Eliminating ACR by dietary-active substances has been found to be one potential strategy to prevent ACR-associated chronic diseases. This study first compared the scavenging ACR efficacy of four purine alkaloids, theophylline (TP), paraxanthine (PXT), theobromine (TB), and caffeine (CAF), and then, TP, CAF, and their metabolites were investigated for their ability to trap ACR in vivo. Our results indicated that TP, which possesses an -NH moiety at the N-7 position, exhibits the best ACR-trapping capacity in vitro, while CAF has a slight ability to trap ACR due to the substitutions by -CH3 at the N-1, N-3, and N-7 positions. After oral administration of TP or CAF, the ACR adducts of TP and the metabolites of TP or CAF (e.g., mono- and di-ACR-TP, mono-ACR-1,3-DMU, and mono-ACR-1-MU) were detected in urinary samples obtained from both TP- and CAF-treated mouse groups by using ultra-performance liquid chromatography-tandem mass spectrometry. The quantification studies demonstrated that TP and its metabolites significantly trapped ACR in a dose-dependent manner in vivo. Furthermore, we also detected those ACR adducts of TP and TP/CAF's metabolites in human urine after four cups of green tea (2 g tea leaf/cup) or two cups of coffee (4 g coffee/cup) were consumed per day. Those results indicated that dietary TP or CAF has the potential capacity to scavenge ACR in vivo.

Syntactic Structure Influences Speech-Gesture Synchronization

It is known that a phrase may have multiple meanings. Phrases such as “green tea cup” may be interpreted with two different meanings—a “green-colored tea cup” or a “cup of green tea.” Then how people know the exact meanings of apparently syntactically ambiguous linguistic expressions? We propose that gesture that accompanies speech may help disambiguate syntactically ambiguous structures. The present study investigated whether the difference in phrase structures influences the production of gestures. Participants produced gestures as they produced a Japanese four-word phrases. We examined all possible synchronization patterns of speech and gestures. We found, for the first time, gestures tended to synchronize with the chunks of words that form a constituent in syntactic structures. Our study suggests that gestures may play an important role in disambiguating syntactically ambiguous phrases. This could be a reason why humans have continuously used gestures even after they acquired a powerful tool of language and why today, they still produce language-redundant gestures.

Is the Association between Green Tea Consumption and the Number of Remaining Teeth Affected by Social Networks?: A Cross-Sectional Study from the Japan Gerontological Evaluation Study Project.

Consumption of green tea without sugar, as well as social networks, are associated with a lower risk of tooth loss. There is a possibility of confounding both factors because tea is often drunk with friends. Therefore, the present study aimed to examine whether green tea consumption is beneficially associated with the number of remaining teeth, while considering social networks. This cross-sectional study was based on the Japan Gerontological Evaluation Study (JAGES) in 2016. Self-administered questionnaires containing questions about green tea consumption were mailed to 34,567 community-dwelling residents aged ≥ 65 years. We used the number of remaining teeth as a dependent variable, and green tea consumption and the number of friends met over the past month (social network size) as independent variables. Linear regression models with multiple imputation were used. A total of 24,147 people responded (response rate = 69.9%), and 22,278 valid data were included into our analysis. Participants’ mean age was 74.2 years (standard deviation = 6.3), and 45.9% were men. Among the participants, 52.2% had ≥ 20 teeth, 34.2% drank 2–3 cups of green tea per day, and 32.6% met ≥ 10 people over the past month. After adjusting for all potential confounders, both higher green tea consumption and a larger social network size were associated with more remaining teeth (both p for trend < 0.001). The association of green tea was greater among those with smaller social networks (p for interaction < 0.05). The protective association of green tea was remarkable among people with smaller social networks.

Green tea consumption effects on coagulation profile

OBJECTIVES: The objective was to study the prothrombin time (PT) and activated partial thromboplastin time (APTT) values among Sudanese regularly drinking green tea.METHODS: This comparative study was conducted from May to November 2018 at the cities of Kosti, Rabak, and Sinnar, Sudan. Two hundred volunteers recruited in this study included individuals who drank more than three cups of green tea per day for at least 1 year or more (n = 100), and another group represented individuals who did not drink green tea (n = 100). Blood samples were collected in ethylenediaminetetraacetic acid and trisodium citrate anticoagulant containers. Coagulometer analyzer machine and standard methods were used for PT and APTT analysis.RESULTS: The study results showed significantly prolonged in both PT and APTT mean values of individuals who drank green tea when compared with those who did not drink green tea. The PT mean values are 19.88 ± 3.7 s vs. 15.43 ± 0.52 s (P < 0.001) and the APTT mean values are 34.94 ± 3.4 s vs. 32.86 ± 3.2 s (P < 0.002). The multiple linear regression analysis confirmed a positive impact relationship between age, drinking green tea, and duration time of drinking green tea with both PT and APTT values.CONCLUSION: The study concludes that daily drinking green tea for a long time could affect an individual's coagulation profile.

Behavioral and dietary risk factors of recurrent urinary tract infection in Chinese postmenopausal women: a case-control study.

ObjectiveThe present study aimed to examine the behavioral and dietary risk factors of recurrent urinary tract infection (RUTI) in postmenopausal patients in China.MethodsWe performed a population-based case–control study with 193 postmenopausal women with RUTI and 193 age-matched healthy female controls with no history of RUTI. The study was conducted between January 2016 and June 2018 in Changzhou, China. Data were collected using an interviewer-based questionnaire, including information on demographics, lifestyle behavior, and habitual diet. Conditional logistic regression analysis was conducted to examine the risk factors associated with RUTI.ResultsWiping from back to front after toilet use, sedentary behavior >6 hours/day, delayed voiding, and chronic constipation were associated with an increased risk of RUTI. Drinking more than three cups of green tea per month showed an inverse association with RUTI. However, there was no evidence of dose dependency for overall consumption. Additionally, the three-cup association involved a small proportion of cases and may reflect statistical artifact.ConclusionsWiping from back to front after toilet use, sedentary behavior, delayed voiding, and chronic constipation are associated with an increased risk of RUTI in postmenopausal women.

Epicatechin-3-Gallate Signaling and Protection against Cardiac Ischemia/Reperfusion Injury.

At concentrations found in humans after ingestion of one to two cups of green tea, epicatechin-3-gallate (ECG) modulates Na/K-ATPase conformation and activity. Akin to ouabain, an archetypal Na/K-ATPase ligand of the cardiotonic steroid (CTS) family, ECG also activates protein kinase C epsilon type (PKCε) translocation and increases the force of contraction of the rat heart. This study evaluated whether, like ouabain, ECG also modulates Na/K-ATPase/Src receptor function and triggers pre- and postconditioning against ischemia/reperfusion (I/R) injury. In vitro, ECG activated the purified Na/K-ATPase/Src complex. In Langendorff-perfused rat hearts, submicromolar concentrations of ECG administered either before or after ischemia reduced infarct size by more than 40%, decreased lactate dehydrogenase release, and improved the recovery of cardiac function. ECG protection was blocked by PKCε inhibition and attenuated by mitochondrial KATP channel inhibition. In a unique mammalian cell system with depleted Na/K-ATPase α1 expression, ECG-induced PKCε activation persisted but protection against I/R was blunted. Taken together, these results reveal a Na/K-ATPase- and PKCε-dependent mechanism of protection by ECG that is also distinct from the mechanism of action of ouabain. These ECG properties likely contribute to the positive impact of green tea consumption on cardiovaascular health and warrant further investigation into the role of cardiac Na/K-ATPase signaling in the cardioprotective effect of green tea consumption. SIGNIFICANCE STATEMENT: Consumption of green tea, the richest dietary source of ECG, is associated with a reduced risk of cardiac mortality. Antioxidant effects of ECG and other tea polyphenols are well known, but reported for concentrations well above dietary levels. Therefore, the mechanism underlying the cardioprotective effect of green tea remains incompletely understood. This study provides experimental evidence that ECG concentrations commonly detected in humans after consumption of a cup of tea trigger the Na/K-ATPase/Src receptor in a cell-free system, activate a CTS-like signaling pathway, and provide PKCε-dependent protection against ischemia/reperfusion injury in rat hearts. Mechanistic studies in mammalian cells with targeted Na/K-ATPase depletion revealed that although Na/K-ATPase does not mediate ECG-induced PKCε activation, it is required for ECG-induced protection against ischemia/reperfusion injury.

Man up! Masculinity and (Homo)sexuality in René Depestre’s Transatlantic World

The question of homosexuality in Francophone Caribbean literature is often overlooked. However, the ways in which the Haitian René Depestre’s Le mât de cocagne (The Festival of the Greasy Pole, 1979) and “Blues pour une tasse de thé vert” (“Blues for a Cup of Green Tea”), a short story from the collection Eros dans un train chinois (Eros on a Chinese Train, 1990) portray homoeroticism and homosexuality begs further study. In these texts, the study of the violence that surrounds the representation of sexuality reveals the sociopolitical implications of erotic and racial images in a French transatlantic world. Hence, the proposed essay “Man up!” interrogates a (Black) hegemonic masculinity inherited from colonialism and the homophobia it generates. This masculinity prescribes normative traits that frequently appear toxic as it thrives on hypersexuality and brute force. When these two traits become associated with violence and homoeroticism, however, they threaten this very masculinity. Initially, Depestre valorizes “solar eroticism,” a French Caribbean expression of a Black sexuality, free and joyful, and “geolibertinage,” its transnational and global expression. Namely, his novel and short story sing a hegemonic and polyamorous heterosexuality, respectively, in a postcolonial milieu (Haiti) and a diasporic space (Paris). The misadventures of his male characters suggest that eroticism in transatlantic spaces has more to do with Thanatos (death) than Eros (sex). Though Depestre formally explores the construction of the other and the mechanisms of racism and oppression in essays, he also tackles these themes in his fictional work. Applying Caribbean feminist and gendered lenses to his fiction bring to light the intricate bonds between racism, sexism and homophobia. Such a framework reveals the many facets of patriarchy and its mechanism of control.

Microbiota Facilitates the Formation of the Aminated Metabolite of Tea Polyphenols Which Trap Deleterious Reactive Endogenous Metabolites (P06-022-19)

ObjectivesThe in vivo mechanism of tea polyphenol-mediated prevention of many chronic diseases is still largely unknown. Studies have shown that accumulation of toxic reactive cellular metabolites, such as ammonia and reactive carbonyl species (RCS), is one of the causing factors to the development of many chronic diseases. The objective of this study is to investigated the in vivo interaction between tea polyphenols and ammonia and RCS. MethodsIn mice, we gave 200 mg/kg tea polyphenol ((-)-epigallocatechin-3-gallate (EGCG) or theaflavin) to CD-1 mice, 129/SvEv specific-pathogen-free (SPF) mice, or germ-free (GF) mice. Urinary and fecal samples were collected in metabolic cages for 24 h. In humans, two healthy volunteers drank 4 cups of Lipton green tea every day for four days. On the fourth day, 24 h urinary and fecal samples were collected after consuming the first cup of tea. Using LC tandem mass, we searched the formation of the aminated and RCS conjugated metabolites of tea polyphenols. Chemical standards were synthesized to confirm the structures of these metabolites. In order to study the impact of gut microbiota on the formation of these metabolites, we also quantified the concentrations of these metabolites in SPF and GF mice. ResultsWe found that both EGCG and theaflavin could rapidly react with ammonia to generate the aminated metabolites. Both tea polyphenols and their aminated metabolites could further scavenge RCS, such as methylglyoxal (MGO), malondialdehyde (MDA), and trans-4-hydroxy-2-nonenal (4-HNE), to produce the RCS conjugates of tea polyphenols and the aminated tea polyphenols. Both the aminated and the RCS conjugated metabolites of EGCG were detected in human after drinking four cups of green tea per day. By comparing the levels of the aminated and the RCS conjugated metabolites in EGCG or theaflavin exposed germ-free (GF) mice and specific-pathogen-free (SPF) mice, we demonstrated that gut microbiota facilitate the formation of the aminated metabolites of tea polyphenols, the RCS conjugates of tea polyphenols, and the RCS conjugates of the aminated tea polyphenols. ConclusionsAltogether, this study provides in vivo evidences that tea polyphenols have the capacity to scavenge toxic reactive metabolic wastes. This finding opens a new window to understand the underlying mechanisms by which drinking tea could prevent the development of chronic diseases. Funding SourcesWe gratefully acknowledge financial support from NIH R01 grant AT008623 to this work.

A cup of green tea can solve many problems!

A cup of green tea can solve many problems!

Microbiota facilitates the formation of the aminated metabolite of green tea polyphenol (-)-epigallocatechin-3-gallate which trap deleterious reactive endogenous metabolites

The in vivo mechanism of tea polyphenol-mediated prevention of many chronic diseases is still largely unknown. Studies have shown that accumulation of toxic reactive cellular metabolites, such as ammonia and reactive carbonyl species (RCS), is one of the causing factors to the development of many chronic diseases. In this study, we investigated the in vivo interaction between (-)-epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in tea leaves, and ammonia and RCS. We found that EGCG could be oxidized to EGCG quinone in mice, and then rapidly react with ammonia to generate the aminated EGCG metabolite, 4′-NH2-EGCG. Both EGCG and its aminated metabolite could further scavenge RCS, such as methylglyoxal (MGO), malondialdehyde (MDA), and trans-4-hydroxy-2-nonenal (4-HNE), to produce the RCS conjugates of EGCG and the aminated EGCG. Both the aminated and the RCS conjugated metabolites of EGCG were detected in human after drinking four cups of green tea per day. By comparing the levels of the aminated and the RCS conjugated metabolites in EGCG exposed germ-free (GF) mice and specific-pathogen-free (SPF) mice, we demonstrated that gut microbiota facilitate the formation of the aminated metabolite of EGCG, the RCS conjugates of EGCG, and the RCS conjugates of the aminated EGCG. By comparing the trapping capacities of EGCG and its aminated metabolite under aerobic and anaerobic conditions, we found that oxygen is not essential for the trapping of reactive species by EGCG and 4′-NH2-EGCG suggesting that EGCG and its aminated metabolite could scavenge RCS in the GI track and in the circulation system. Altogether, this study provides in vivo evidences that EGCG has the capacity to scavenge toxic reactive metabolic wastes. This finding opens a new window to understand the underlying mechanisms by which drinking tea could prevent the development of chronic diseases.

The Anti-Obesity Effects of Green Tea: A Controlled, Randomized, Clinical Trial

Background: Obesity is a global health threatening issue with increasing prevalence in the developed and developing world. The limited efficacy and side effects of conventional treatments motivated the researchers to look for novel, safe, and effective therapeutic strategies. Objectives: The current study aimed at investigating the anti-obesity effects of green tea in a population in North of Iran. Methods: The current single-blind, placebo-controlled, parallel, clinical trial was conducted in Guilan outpatient clinic in Rasht, Iran, from January to December 2015. Eligible subjects were randomly allocated into 2 groups of green tea and control. In the GT Group, a cup of green tea and in the C group an equal amount of mineral water was taken 30 minutes after breakfast and lunch. The outcomes including body weight (BW), body mass index (BMI), hip circumference, waist circumference, and waist-to-hip ratio were measured at baseline, as well as 8 and 12 weeks after the intervention (T0,T_1, T_2). Results: Finally, data obtained from 84 cases in groups GT (n = 41) and C (n = 43) were analyzed. No significant difference was observed in terms of baseline demographics and measurements between the 2 groups including male/female (P = 0.766), age (P = 0.376), weight (P = 0.846), height (P = 0.413), waist circumference (P = 0.619), hip circumference (P = 0.619), and waist-to-hip ratio (P = 0.301). According to the intragroup analyses, the trend of changes from baseline to 12 weeks after intervention were significant in both groups (P = 0.001); BW (79.88 ± 7.06 to 72.44 ± 6.82 kg) and (80.21 ± 7.16 to77.07 ± 7.22 kg) , BMI (29.95 ± 1.79 to 26.86 ± 2.59 kg/m2) and (29.69 ± 2.1 to 27.07 ± 2.22 kg/m2) , waist circumference (87.77±6.06 to 83.913 ± 6.13 cm) and (86.94 ± 8.05 to 85.23 ± 7.89 cm), and hip circumference (102.41 ± 7.35 to 98.3 ± 7.54 cm) and (101.02 ± 8.47 to 99.31 ± 8.81 cm) in GT and C groups, respectively. However no such difference was observed in waist/hip ratio in the GT and C groups (P = 0.087) and (P = 0.322), respectively. A significant difference was observed at T1 (P = 0.024 and P = 0.025) and T2 (P = 0.025 and P = 0.006), according to weight and BMI, respectively. However, the differences were not statistically significant based on the other variables. Conclusions: Green tea could be a safe and effective choice for patients with obesity. However, further well-designed trials are required to confirm these findings.

Safety assessment of green tea based beverages and dried green tea extracts as nutritional supplements

The safety of green tea infusions and green tea extract (GTE)-based products is reviewed regarding catechins. Epigallocatechin 3-gallate (EGCG), the major catechin present in green tea, is suspected of being responsible for liver toxicity reported in humans consuming food supplements. Intake of EGCG with green tea infusions and GTE-based beverages is up to about 450mg EGCG/person/day in Europe and higher in Asia. Consumption of green tea is not associated with liver damage in humans, and green tea infusion and GTE-based beverages are considered safe in the range of historical uses. In animal studies, EGCG’s potency for liver effects is highly dependent on conditions of administration. Use of NOAELs from bolus administration to derive a tolerable upper intake level applying the margin of safety concept results in acceptable EGCG-doses lower than those from one cup of green tea. NOAELs from toxicity studies applying EGCG with diet/split of the daily dose are a better point of departure for risk characterization. In clinical intervention studies, liver effects were not observed after intakes below 600mg EGCG/person/day. Thus, a tolerable upper intake level of 300mg EGCG/person/day is proposed for food supplements; this gives a twofold safety margin to clinical studies that did not report liver effects and a margin of safety of 100 to the NOAELs in animal studies with dietary administration of green tea catechins.

Does green tea consumption improve the salivary antioxidant status of smokers?

Objective Considering the higher rate of oral cancer, and reduction in salivary antioxidants in smokers as indicated in previous studies, antioxidant- containing nutrients such as green tea, seem to be beneficial in counteracting against oxidative stress in this group. This study assessed the salivary total antioxidant alteration in smokers compared to nonsmokers, after short-tem (7days) and long-term (3 weeks), green tea drinking. DesignIn this experimental study, 20 volunteer moderate-to-heavy male smokers, and 20 matched healthy non-smokers were selected to participate, according to the inclusion criteria. Participants were instructed to drink two cups of green tea per day, by dissolving 2g of green tea in 150ml of hot water for each cup. After saliva collection, antioxidant capacity of saliva was measured at baseline, after 7days, and after 21days. Statistical evaluation was done by SPSS 21, using paired samplet tests, one-way ANOVA and Bonferroni tests. Results At day zero nonsmokers had a higher antioxidant capacity than smokers (686.6±62.22 vs. 338.8±59.9) mM/50μl, P<0.001. There was also a significant difference between two groups in salivary total antioxidant capacity after one week and three weeks of green tea consumption (P<0.001). However, there was an upward trend in both smokers and non-smokers over the study period (after tea drinking). In addition, a significant difference was found in total antioxidant capacity alteration in smokers compared to non-smokers from baseline to day 21. ConclusionsResults support the effectiveness of green tea consumption in salivary antioxidants enhancement in smokers, in both the short- and long term.

Periodontal Status and Relation with Salivary Total Antioxidant Capacity after Green Tea Consumption in Smokers

ABSTRACT Aim Smoking is a significant source of oxidative stress. Also, the disruption in equilibrium between free-oxygen radicals and antioxidants plays a pivotal role in the progression of periodontal inflammation. Green tea with antioxidant potential might have an effect on periodontal disease. This study evaluated the periodontal status in different groups of smokers compared with nonsmokers and investigates the association with salivary antioxidant levels after a period of green tea consumption. Materials and methods In this interventional study, 60 healthy males, including 20 light and 20 heavy cigarette smokers and 20 control nonsmokers, participated. Periodontal status was determined by the Community Periodontal Index of Treatment Needs (CPITN) at the beginning of the study. All participants were asked to consume a total of two cups of green tea (4 gm) per day. Total antioxidant capacity (TAC) of saliva was measured at baseline and after 21 days. Statistical evaluation was done by Statistical Package for the Social Sciences (SPSS) version 21 software. Results The Pearson correlation coefficient between CPITN and salivary TAC showed significant correlation in light and heavy smokers (p = 0.001 and p = 0.003 respectively). Changes in salivary TAC from baseline to day 21, after green tea consumption, in subjects with CPITN ≤ 18 were 139 (± 61.5), and 66.16 (± 67.37) in subjects with CPITN &gt; 18. There was a significant interaction effect between time of TAC evaluation and patients' periodontal state (p = 0.009). Conclusion This study confirmed the association between periodontal status and smoking, and the association with salivary antioxidant capacity. A significant alteration in TAC of whole saliva in cases with clinical periodontal problems after green tea consumption was indicated. Clinical significance Considering the safety and availability of green tea, it can be used as a preventive or supplementary treatment in periodontal problems, especially in smokers, after further investigation. How to cite this article Bakhtiari S, Azimi S, Mansouri Z, Kruger E, Tennant M, Namdari M. Periodontal Status and Relation with Salivary Total Antioxidant Capacity after Green Tea Consumption in Smokers. Int J Experiment Dent Sci 2017;6(2):61-64.

Innovative strategy of cancer treatment with the combination of green tea catechins and anticancer compounds

Human cancer development involves durable genetic changes caused by carcinogens, pro-inflammatory cytokines and chemokines, and simultaneous inflammation in cancer microenvironment. Green tea containing non-toxic anti-inflammatory green tea catechins is an acknowledged cancer preventive. This paper first introduces two results that 10 Japanese-size-cups (150 ml/cup) of green tea per day delayed cancer onset in primary cancer prevention and daily green tea supplemented with tablets of green tea extract equivalent to 10 cups prevented colorectal adenoma recurrence in tertiary cancer prevention. The results allowed us to find synergistic anticancer effects in both in vitro and in vivo experiments with the combinations of (-)-epigallocatechin gallate (EGCG) or green tea extract and two non-steroidal anti-inflammatory drugs (NSAIDs), such as sulindac and celecoxib. We next collected the results of numerous investigators as follows: the combinations of EGCG and 37 anticancer compounds, which include NSAIDs, phytochemicals, and anticancer drugs, generally induced in vitro synergistic anticancer effects on 54 human cancer cell lines derived from various cancer tissues, and the combinations of EGCG, or green tea extract and 13 anticancer compounds showed reduction of tumor volume in xenograft mouse models implanted using various human cancer cell lines. For example, average reduction of tumor volume with combinations, anticancer compounds alone, EGCG alone, or vehicle for control were 70.3%, 33.7%, 26.5%, or 0%, respectively. Especially, the complete elimination of tumor development on human prostate cancer cell line PC-3ML was found in xenograft mouse models treated with combinations of EGCG and paclitaxel, and EGCG and docetaxel. The amount of EGCG necessary for complete elimination of tumor in mice corresponds to 6 - 9 cups of green tea for humans. Moreover, the combination was reported to inhibit stem cell characteristics. The combination resulting in 70.3% reduction of tumor volume makes it possible to innovate cancer treatment, and the cancer patient could achieve improved quality of life without suffering the side effects of anticancer drugs, which results in “the final goal of cancer therapy is the survival of cancer patients with coexistence of cancer cells” presented by Prof. Tomizo Yoshida, a mentor of Japanese pathologists.