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Two colorimetric methods are used to determine the total polyphenol contents of tea, namely, "the Folin-Ciocalteu method," defined by the International Organization for Standardization, and the "iron tartrate method," specified in the Standard Tables of Food Composition in Japan. In this study, we compared the Folin-Ciocalteu and iron tartrate methods using green tea extracts. When comparing the 2 methods, the sum of the 4 major catechins measured using high-performance liquid chromatography (HPLC) was regarded as the standard value. The total polyphenol contents obtained using the Folin-Ciocalteu method were closer to the HPLC value than those obtained using the iron tartrate method. However, the iron tartrate method is adequate if the current official method is improved, that is, our results suggest that the coefficients appropriate for common green tea varieties, as well as the degree and duration of cover cultivation, in the official iron tartrate method must be considered. [ABSTRACT FROM AUTHOR]

In today's Japan, many individuals live in what is known as a stress society, where daily stress has become a common occurrence. The causes of stress vary from person to person and may be attributed to factors such as social environment and human relationships. Excessive stress can result in oxidative stress, which can have significant impact on both the mind and body. In fact, severe stress can lead not only to sleep disorders such as insomnia but also to mental illnesses such as depression. Theanine, a component derived from glutamic acid and ethylamine found in the roots of tea plants, is present in green tea and contributes to its umami taste. It has been approved as a functional food for stress and sleep. Theanine is known for its relaxing effects and its ability to improve sleep quality. Studies have also indicated its effectiveness in treating mental illnesses such as schizophrenia and depression. By understanding the functionality of theanine and investigating tea-based beverages that can be ingested most efficiently, it is believed that we can contribute to the prevention of diseases associated with reactive oxygen species generated by stress. In this study, we first evaluated the antioxidant effects of theanine using electron spin resonance (ESR) equipment. Next, we measured the amount of theanine in tea beverages using a liquid chromatograph/fluorescence detector (LC/FL). The ESR results demonstrated that theanine exhibits antioxidant activity by inhibiting the generation of reactive oxygen species through copper ions. Moreover, we found that Camellia sinensis, represented by green tea and black tea, contains a significant amount of theanine. [ABSTRACT FROM AUTHOR]

Camellia sinensis leaves are one of the most economically important crops, and various tea cultivars are available in Japan. In the present study, we compared the constituents of Camellia sinensis var. sinensis cv. Yabukita ("Yabukita"), a standard tea cultivar, and those of C. sinensis var. sinensis cv. Sayamakaori ("Sayamakaori"), grown in Saitama Prefecture, using proton nuclear magnetic resonance (1H-NMR) metabolomics technology. Principal component analysis and hierarchical cluster analysis of 1H-NMR spectroscopic data of the MeOH extracts of C. sinensis leaves revealed differences in the metabolic profiles of each tea cultivar. Chromatographic separation based on 1H-NMR spectral data showed that kaempferol 3- O -β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 6)-β-D-glucopyranoside was a distinct component of "Sayamakaori". This compound can be used as maker for the identification of "Sayamakaori" and the maintenance of its quality. [ABSTRACT FROM AUTHOR]

Bancha is a popular type of green tea in Japan, rich in tea polyphenols (TPs) and has a more astringent aroma with a less aromatic and strong character that complements functional foods. The blanching process is used to extract TPs and remove unwanted microorganisms, as well as inhibit phenolic oxidation. This study proposed a green tea blanching process followed by spray drying the extracts with maltodextrin. Furthermore, it is focused on maximizing the major chemical components of green tea (i.e., catechins, caffeine, and phenolic contents) based on powder particle size obtained through Multiple Response Surface Methodology optimizations. The results show that the proposed model accurately predicts leached-spray dried green tea's total catechin and caffeine content, with a coefficient of 0.9475 and 0.8692, respectively. This process yielded composite desirability of 0.9751, while individual desirability yielded excellent results of 1.0000, 0.9188, 1.0000, and 0.9839 for catechin, caffeine, phenol content, and powder. The settings appear to yield functional results for entire responses. Due to the concerns in tropical skin nutrition applications, smaller particle size green tea can promote better adsorption than larger sizes. [ABSTRACT FROM AUTHOR]

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Background/objectives: Circulating bile acid (BA) profiles change with lifestyle and are closely related to intestinal BA metabolisms such as deconjugation and conversion to secondary BAs. The composition of BA in the blood is involved in systemic nutrient metabolism and intestinal health. Herein, we explored the associations of lifestyle and physical fitness with the circulating BA profile of middle-aged men., Methods: Data of 147 male participants (aged 50-64 years; BMI < 26 kg/m 2 ; no medication for diabetes or dyslipidemia) from the Japan Multi-Institutional Collaborative Cohort study were analyzed. Serum concentrations of 15 types of BAs were examined for associations with variables on dietary habits, physical-activity habits, and physical fitness., Results: Green tea intake was positively associated with the deconjugation ratio of total BAs ( p = 0.028) and negatively associated with secondary BA levels (free deoxycholic acid [DCA] ( p = 0.078), glyco-DCA ( p = 0.048), and tauro-DCA ( p = 0.037)). In contrast, physical activity was negatively associated with the deconjugation ratio ( p = 0.029) and secondary BA levels (free DCA ( p = 0.098), and free lithocholic acid ( p = 0.009)). Grip strength was also negatively associated with secondary BA levels (tauro-DCA ( p = 0.041)) but was not associated with the deconjugation ratio. Energy and fat intake and skeletal muscle mass were not associated with the deconjugation ratio or secondary BA levels., Conclusions: The study findings suggest that lifestyle-associated changes in serum deconjugated and secondary BAs indicate improvements in nutrient metabolism and the intestinal environment.

Background: The prospective studies on the effect of particular type of tea consumption, especially green tea, on depressive symptoms are limited.Objective: The aim of this study is to investigate the prospective association between green tea consumption and depressive symptoms in a large general adult population.Methods: This prospective cohort study investigated 7524 participants aged 25 to 90 years from May 2013 to December 2018 and they were free of cardiovascular disease, cancer, and depressive symptoms at baseline. Green tea consumption was obtained through a validated food frequency questionnaire. Depressive symptoms were assessed by using the Self-Rating Depressive Scale (SDS). The association between green tea consumption and depressive symptoms was analyzed by Cox proportional hazards regression models.Results: A total of 1064 first incident cases of depressive symptoms (SDS ≥45) occurred during 14,661 person-years of follow-up (median follow-up of 2.0 years). In the crude model, the hazard ratios (95% confidence intervals) were 1.00 (reference), 0.95 (0.81, 1.12), 0.97 (0.83, 1.14) and 0.95 (0.79, 1.14), respectively. After adjusting for demographic characteristics, lifestyle factors, and dietary intake, the multivariable adjusted hazard ratios (95% confidence intervals) were 1.00 (reference), 0.88 (0.74, 1.05), 0.84 (0.69, 1.02) and 0.78 (0.63, 0.97), respectively.Conclusions: The prospective study suggests that frequent green tea consumption is associated with a decreased risk of depressive symptoms in the general Chinese population. [ABSTRACT FROM AUTHOR]

Background: Isolated trees are often planted in agricultural landscapes around the world, but their planting background often remains unclear. In this study, we examined the history of demarcation trees in Ibaraki Prefecture in eastern Japan by using land dispute records mainly from the early modern period (from 1600 to 1868), the Rapid Survey Map (RSM) drawn in the late nineteenth century, demarcation tree records from 2011, and interviews of the local residents. Methods: We reviewed 39 documents on land disputes to examine the temporal and spatial usage of demarcation tree species in the early modern period. The association between the present distribution of 1486 individuals of six demarcation tree species and past land use in the RSM were analyzed with Fisher's exact test and residual analysis. In addition, we conducted interviews with 48 farmers, most of whom were over 60 years old. Results: The demarcation plants in vast communal lands and village boundaries in the early modern period were mostly visually prominent tall trees, usually pines. In contrast, smaller trees were planted for demarcation in small-scale areas of forests and farmlands. Although Pourthiaea villosa (Thunb.) DC. Has been planted since the mid-eighteenth century, its planting seems to have accelerated as communal forests were divided mainly in the Meiji period (from 1868 to 1912). The present dominant state of Deutzia crenata Siebold et Zucc. in older farmlands and its ritual use, history of upland field development in the Kanto region, and ancient demarcation use in central Japan indicate its original use may date back to the medieval (from 1185 to 1600) or ancient ritsuryo period (from the seventh century to 1185). Tea (Camellia sinensis (L.) Kuntze) and mulberry (Morus spp.) individuals were considered as early modern or modern crop remnants. Results from the map-based analysis and interviews clarified the recent increase in the use of Euonymus japonicus Thunb. and Celtis sinensis Pers. for demarcation. Conclusions: Chronologically dynamic anthropogenic legacies have shaped the present agricultural landscape with different demarcation tree species. A better understanding of the dynamic transformation of vegetation under human influence adds to the historical heritage value of the landscape and should motivate its conservation. [ABSTRACT FROM AUTHOR]

The association between the intake of non-alcoholic beverages and CVD in Asians is uncertain. The intake of non-alcoholic beverages was estimated in 77 407 participants of the Japan Public Health Centre-based cohort study aged 45–74 years. The Cox regression calculated the hazard ratios (HR) and 95 % CI for incident CVD according to sex-specific quintiles of intake of non-alcoholic beverages. A total of 4578 incident CVD (3751 strokes and 827 CHD) were diagnosed during a 13·6-year median follow-up. The risks of stroke and total CVD were lower for the highest v. lowest intake quintiles of non-alcoholic beverages in men and women: the multivariable HRs (95 % CIs) were 0·82 (0·71, 0·93, Ptrend = 0·005) and 0·86 (0·76, 0·97, Ptrend = 0·02), respectively, in men and were 0·73 (0·63, 0·86, Ptrend = 0·003) and 0·75 (0·65, 0·87, Ptrend = 0·005), respectively, in women. The reduced risk was evident for both ischaemic and haemorrhagic strokes and was mainly attributable to green tea consumption. The intake of non-alcoholic beverages from coffee and other beverages was not associated with the risk of CVD in both men and women. Also, there was no association between the intake of non-alcoholic beverages and the risk of CHD in either sex. In conclusion, the risks of stroke and total CVD were lower with a higher intake of non-alcoholic beverages in Japanese men and women. [ABSTRACT FROM AUTHOR]

Objectives Coffee, green tea, and caffeine are potential preventive factors for dementia, but the underlying evidence is insufficient. This study aimed to examine associations between the consumption of coffee, green tea, and caffeine and dementia risk in middle‐aged and older people. Methods: This was a cohort study with an 8.0‐year follow‐up. Participants were community‐dwelling individuals (n = 13,757) aged 40–74 years. A self‐administered questionnaire survey was conducted in 2011–2013. Predictors were the consumption of coffee/green tea, from which caffeine consumption was estimated. The outcome was incident dementia obtained from the long‐term care insurance database. Covariates were demographic factors, body mass index, physical activity, energy, smoking, drinking, and disease history. Adjusted hazard ratios (HRs) were calculated using Cox proportional hazards models. HRs were also calculated using a Cox model with delayed entry. Results: The number of dementia cases during the study period was 309. Participants with higher coffee consumption had lower HRs (adjusted p for trend = 0.0014), with the fifth quintile (≥326 ml/day) having a significantly lower HR (0.49, 95% confidence interval [CI]: 0.30–0.79) than the first quintile (<26 ml/day, reference). Similarly, participants with higher caffeine consumption had a significantly lower HR (adjusted p for trend = 0.0004) than the reference. The Cox model with delayed entry yielded similar results. These associations were significant in men, but not in women. Moreover, participants who consumed 2–2.9 cups/day and ≥3 cups/day of coffee had lower HRs (0.69, 95% CI: 0.48–0.98 and 0.53, 95% CI: 0.31–0.89, respectively) than those who consumed 0 cup/day. The association between green tea consumption and reduced dementia risk was significant (adjusted p for trend = 0.0146) only in the 60–69 years age subgroup. Conclusions: High levels of coffee and caffeine consumption were significantly associated with a reduced dementia risk in a dose‐dependent manner, especially in men. Moreover, coffee consumption of ≥3 cups/day was associated with a 50% reduction in dementia risk. [ABSTRACT FROM AUTHOR]

Heavy application of nitrogen (N) in tea (Camellia sinensis (L.)) plantations causes various environmental problems. To date, studies on N flows have been limited to the tea plantation level, but the crucial drivers of N flows are consumers, not farmers. Therefore, this study aimed to evaluate changes in N flows concerning green tea production and consumption in Japan from 1965 to 2016 using the N footprint concept. Nitrogen use efficiency (NUE), virtual N factor (VNF), and N footprint were calculated using a Monte Carlo method from data for 17 parameters obtained from the literature review. The VNF for green tea in Japan decreased from 54.5 in 1991 to 30.8 in 2016. The major reasons for this decrease were (i) increased NUE in plantations and (ii) increased consumption of ready-to-drink (RTD) tea, matcha, and powdered tea, indicating an increase in the efficiency of N intake from green tea by consumers. The decrease in VNF resulted in a reduction in N footprint from green tea consumption. However, the decline in N footprint since 2004 is not derived from the decrease in VNF but mainly from reduced green tea consumption. A sensitivity analysis revealed that the parameters associated with the extraction efficiency of tea, powdered tea production, and the amount of tea leaves used for RTD production strongly affected VNF estimation. [ABSTRACT FROM AUTHOR]

l-theanine (γ-glutamylethylamide), an amino acid in green tea, has been shown to affect brain functions by relieving stress disorders, improving mood, and maintaining normal sleep. However, the cognitive functions for which theanine is effective are unclear. This study aimed to clarify which cognitive functions are positively affected by intake of l-theanine. A double-blind, randomized, placebo-controlled study was conducted. The subjects were Japanese men and women aged 50–69 years. Mini Mental State Examination-Japanese version score was 24 or higher. Cognitrax was used as a test battery for cognitive function. Evaluations were performed before the intervention, after a single dose of l-theanine, and after 12 weeks of regular intake. The single dose of l-theanine reduced the reaction time to attention tasks (Stroop test, Part 1), and it increased the number of correct answers and decreased the number of omission errors in working memory tasks (4-Part continuous performance test, Part 4). In conclusion, our study indicated that l-theanine may contribute to improving attention, thus enhancing working memory and executive functions. Clinical Trial No.: UMIN000033812. [ABSTRACT FROM AUTHOR]

Objective: To examine the association between green tea and coffee intake and cognitive decline in older adults. Design: A prospective cohort study. The average intake of green tea and coffee in the previous year was assessed through a dietitian interview using a dietary questionnaire. A Mini-Mental State Examination (MMSE) was conducted up to six times biennially. Cognitive decline was screened using the MMSE; its incidence was defined as the first time a score of <27 points was obtained in a biennial test from the baseline. Hazard ratios for incidence of cognitive decline were estimated according to the intake of the two beverages using multivariable Cox proportional hazard regression, controlling for sociodemographic and lifestyle factors. Setting: The National Institute for Longevity Sciences, Longitudinal Study of Aging (NILS-LSA) in Japan. Participants: Men (n 620) and women (n 685), aged 60–85 years, from the NILS-LSA. Results: During a mean of 5·3 (sd 2·9) years of follow-up, 432 incident cases of cognitive decline were observed. Compared with participants who consumed green tea

To ascertain whether habitual green tea consumption is associated with sarcopenia among Japanese older adults, using the screening tool for sarcopenia (SARC-F). This cross-sectional study in Mukawa, Hokkaido, Japan, was conducted between June and September 2022 and included 364 Japanese participants older than 65 y. Habitual green tea consumption and energy intake were ascertained using a validated self-administered food frequency questionnaire. Sarcopenia was evaluated using the SARC-F. Multivariable logistic regression analysis was used to estimate the odds ratio (OR) and 95% confidence interval (CI) of sarcopenia risk across participant tertiles of green tea consumption, with adjustments for age, sex, body mass index, living alone, habitual exercise, walking hours, current smoking status, current alcohol consumption status, energy intake, protein intake, vegetable intake, and fruit intake. In this study of 364 participants (154 men and 210 women), the prevalence of sarcopenia risk was 9.3%. The multivariable-adjusted OR [95% CI] of green tea consumption for ≥1 cup/d compared with that of <1 cup/wk of sarcopenia was 0.312 [0.129-0.752]. Higher habitual green tea consumption was inversely associated with sarcopenia among Japanese older adults. Further longitudinal studies are required to confirm these findings.

Purpose: Experimental studies suggested that green tea may have an anticancer effect on hematologic neoplasms. However, few prospective studies have been conducted.Methods: A total of 65,042 individuals aged 40-79 years participated in this study and completed a self-administered questionnaire about their lifestyle and medical history at baseline (1988-1990). Of these, 52,462 individuals living in 24 communities with information on incident hematologic neoplasms available in the cancer registry, who did not have a history of cancer and provided valid information on frequency of green tea consumption, were followed through 2009. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the incidence of hematologic neoplasms according to green tea consumption were analyzed.Results: The incidence of hematologic neoplasms during a median follow-up of 13.3 years was 323. Compared with the never-drinkers of green tea, the multivariate HRs and 95% CIs for total hematologic neoplasms in green tea drinkers of ≤ 2 cups/day, 3-4 cups/day, and ≥ 5 cups/day were 0.65 (0.42-1.00), 0.73 (0.47-1.13), and 0.63 (0.42-0.96), respectively. The association was more prominent for acute myeloid leukemias and follicular lymphomas.Conclusions: The present cohort study suggests a protective effect of green tea against hematologic neoplasms, especially acute myeloid leukemias. [ABSTRACT FROM AUTHOR]

Objectives: Modifiable risk factors for knee osteoarthritis (OA) have not been studied in detail. This study aimed to determine lifestyle-related modifiable factors of symptomatic knee osteoarthritis in an East Asian population.Study Design: This 5-year cohort study involved 11,091 individuals (age range 40-72 years) living in the Murakami region of Niigata, Japan, who did not have a history of knee OA. At baseline, information on sociodemographic characteristics, body size, lifestyle, and living condition was obtained using a self-administered questionnaire.Main Outcome Measures: Incident symptomatic knee OA observed at hospitals and orthopaedic clinics in the five years to 2016. Clinical grades of knee OA were based on the Kellgren-Lawrence scale. P for trend was assessed to examine linear associations between predictors and the outcome in multiple logistic regression analysis.Results: The mean age of participants was 58.1 (SD 9.3) years. The number of cases of grade 2 or more incident knee OA was 429. In men, older age (P for trend < 0.0001), higher BMI (P for trend < 0.0001), higher METs score (P for trend = 0.0150), less smoking (P for trend = 0.0249), and lower green tea consumption (P for trend = 0.0437) were associated with incident knee OA. In women, older age (P for trend < 0.0001), higher BMI (P for trend < 0.0001), and alcohol consumption (P = 0.0153) were associated with incident knee OA.Conclusions: Several lifestyle-related factors were found to be associated with incident knee OA and exhibited sex-dependent differences. In particular, higher consumption of green tea was associated with a lower incidence of knee OA in men. [ABSTRACT FROM AUTHOR]

The aim of our study was to assess the association between green tea consumption and all-cause and cause-specific mortality in a pooled analysis of eight Japanese population-based cohort studies. Pooled hazard ratios (HR) and 95% confidence intervals (CI), derived from random effects models, were used to evaluate the associations between green tea consumption, based on self-report at baseline, and risk of all-cause and cause-specific mortality. During a mean follow-up of 17.3 years, among 313,381 persons, 52,943 deaths occurred. Compared with individuals who consumed < 1 cup/day, those in the highest consumption category (≥ 5 cups/day) had a decreased risk of all-cause mortality [the multivariate-adjusted HR was 0.90 (95% CI 0.87–0.94) for men and 0.82 (0.74–0.90) for women]. A similar inverse association was observed for heart disease mortality [HR 0.82 (0.75–0.90) for men, and 0.75 (0.68–0.84) for women], and cerebrovascular disease mortality [HR 0.76 (0.68–0.85) for men, and 0.78 (0.68–0.89) for women]. Among women, green tea consumption was associated with decreased risk of total cancer mortality: 0.89 (0.83–0.96) for the 1–2 cups/day category and 0.91 (0.85–0.98) for the 3–4 cups/day category. Results for respiratory disease mortality were [HR 0.75 (0.61–0.94)] among 3–4 cup daily consumers and [HR 0.66 (0.55–0.79)] for ≥ 5 cups/day. Higher consumption of green tea is associated with lower risk for all-cause mortality in Japanese, especially for heart and cerebrovascular disease. Moderate consumption decreased the risk of total cancer and respiratory disease mortality in women. [ABSTRACT FROM AUTHOR]

Highlights • UHPLC–HRMS fingerprints enabled green tea classification according to their origin. • Green teas from China, Japan & South Korea could be recognized based on their metabolome. • Supervised statistical models showed excellent recognition and prediction ability. • Phospholipids, esters of phenolic acids and catechins were the most important markers of geographic origin of green teas. Abstract The quality of green tea is influenced by many factors, geographic origin being one of high importance, as this parameter is typically associated with tea quality grade. However, in some cases, fraudulent practices such as mislabelling of geographic origin may take place. In this pilot study, aimed at green tea authentication, we investigated whether metabolic fingerprinting based on ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC–HRMS) enables sample classification to be achieved. In total, 54 authentic samples of green tea originating from China (n = 29), Japan (n = 17) and South Korea (n = 8) were available for experiments. To isolate even less polar metabolites, a dichloromethane/methanol (1:1. v/v) mixture was used for extraction. The data generated by the analysis of green tea extracts were processed by both unsupervised and supervised chemometric methods. The resulting predictive models document the applicability of this approach for green tea classification based on geographic origin. [ABSTRACT FROM AUTHOR]

Fairyfly (Hymenoptera, Mymaridae) egg parasitoids of the tea green leafhopper Empoasca (Matsumurasca) onukii Matsuda (Hemiptera, Cicadellidae), an economically important pest in Asia of the tea plant, Camellia sinensis, were identified from specimens reared in Japan. Using a combination of genetic and morphological evidence, Anagrus (Anagrus) rugmanjonesi Triapitsyn & Adachi-Hagimori, sp. n., is described and illustrated. It is shown to be different from the most similar A. turpanicus Triapitsyn & Hu, an egg parasitoid of a leafhopper pest of cultivated grapes which is known from Xinjiang Uyghur Autonomous Region in China. Mitochondrial and nuclear ribosomal DNA sequence data provide clear evidence for the separation of A. rugmanjonesi from A. turpanicus and other members of the Anagrus incarnatus Haliday species complex. A key to females of the Japanese species of Anagrus Haliday is given. Two other species of Mymaridae, Arescon enocki (Subba Rao & Kaur) and Stethynium empoascae Subba Rao, are also identified, albeit the latter one only tentatively. Both latter taxa are newly recorded from Japan, and E. onukii represents their new host association. [ABSTRACT FROM AUTHOR]

Purpose: Serum γ-glutamyltransferase (GGT) has been proposed as a marker of oxidative stress. Here, we examined the association between serum GGT and the dietary intake of polyphenols, which have antioxidant properties.Methods: A cross-sectional survey including 7960 apparently healthy Japanese men (aged 22-86 years) who participated in health checkups was conducted in Shizuoka, Japan. We analyzed these subjects’ clinical serum parameters and lifestyle factors, including dietary polyphenol intake, which was evaluated by a self-administered questionnaire and by matching the subjects’ food consumption data with our original polyphenol content database.Results: The average intake of polyphenols was 1157 ± 471 mg/day, and green tea was the largest source of polyphenols at 40%, followed by coffee at 36%. Dividing the population according to quintiles of total polyphenol intake, the difference in polyphenol intake from coffee between the groups was much greater than the difference in polyphenol intake from green tea. The analysis of the association between polyphenol intake and biological parameters showed a significant negative association between polyphenol intake and the levels of systolic and diastolic blood pressure (SBP and DBP), GGT, and alanine aminotransferase (ALT) after adjusting for age, smoking habit, energy intake and alcohol intake. The GGT levels were inversely associated with the polyphenol intake from coffee, but not with that from green tea. Multivariable linear regression analyses demonstrated that the subjects’ GGT levels were negatively and independently associated with their polyphenol intake.Conclusions: The intake of total polyphenol including coffee as a major contributor is inversely associated with the serum GGT concentration in Japanese males. [ABSTRACT FROM AUTHOR]

We aimed to investigate whether coffee, green tea, and caffeine intake are associated with liver cancer risk, using data of a prospective cohort study. This study included 30,824 participants (14,240 men and 16,584 women) aged 35 years or older in the Takayama study, which was launched on September 1, 1992. The consumption frequencies of coffee and green tea were assessed using a self-administered questionnaire. Caffeine intake was estimated from the consumption frequencies of caffeine-containing beverages and foods and their caffeine content per serving. The incidence of liver cancer was confirmed using regional population-based cancer registries. During the follow-up period of 16 years, a total of 172 participants developed liver cancer. The adjusted hazard ratios and 95% confidence intervals (CIs) in relation to coffee consumption were 0.65 (95% CI: 0.46–0.93) for less than once per day, 0.63 (95% CI: 0.39–1.02) for once per day, and 0.40 (95% CI: 0.20–0.79) for twice per day or more, compared with nondrinkers. No associations with green tea, black tea and caffeine intake were observed. The present study confirmed that coffee consumption significantly reduces liver cancer risk and raises the possibility that caffeine intake might not account for the association. [ABSTRACT FROM AUTHOR]

Background and Objectives: Despite the demonstrated protective effects of green tea and coffee intake against several chronic diseases, finding between studies have not been consistent. One potential reason of this discrepancy is the imprecision in the measurement of tea or coffee consumption using food frequency questionnaire (FFQ) and food record (FR) in epidemiological studies.Methods and Study Design: In a sample of 57 healthy Japanese women, intake of green tea and coffee was estimated by a validated FFQ and a 3-day FR, while their plasma and urine concentrations of polyphenol biomarkers were measured by HPLC. The polyphenols assessed included (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC) and (-)- epicatechin (EC), caffeic acid (CA) and chlorogenic acid (CGA).Results: Green tea consumption estimated by FFQ and FR showed moderate association, while strong association was detected for coffee consumption. Urinary green tea polyphenol concentrations were moderately-strongly associated with FR-estimated intake, while the associations were weak with FFQ. Similarly, coffee polyphenols in urine were moderately associated with FR-estimated coffee intake, whereas FFQ showed poor correlation. The associations between urinary and plasma polyphenols ranged from moderate to high.Conclusions: The results indicated that firstly, the FFQ tends to overestimate green tea intake. Secondly, the urinary polyphenols are preferred over plasma polyphenols as a potential surrogate marker of the short-term green tea and coffee intake, while their use as an indicator of long-term consumption is not reliable. [ABSTRACT FROM AUTHOR]

Background and Objectives: Recent observational studies have suggested a positive association of white rice and protective associations of green tea and coffee with the risk of diabetes. However, none have examined the interaction between these dietary factors on the risk of diabetes. We prospectively investigated the effect modification of green tea and coffee on the association between rice and incident diabetes in elderly Japanese men and women.Methods and Study Design: Among subjects who participated in the baseline survey (2004-2007), 11717 (91 %) subjects responded to the follow-up survey (2010-2012). By using multiple logistic regression analysis, ORs of incident diabetes were calculated according to categories of cereal food, green tea, and coffee intakes, examining also the effect modification of green tea and coffee.Results: 464 new cases of diabetes were identified. Women, but not men, showed a positive association of rice intake (trend p=0.008) and an inverse association of green tea intake (trend p=0.02) with incident diabetes. Coffee showed no association with incident diabetes either in men or women. In the analysis stratified by green tea intake, the association between rice and diabetes disappeared among women with an intake of >=7 cups/d of green tea (interaction p=0.08).Conclusions: Rice intake was associated with an increased risk of diabetes only in women, and women with a higher intake of green tea had a lower risk of diabetes. A high intake of green tea may be protective against increased risk of diabetes with a higher intake of rice in women. [ABSTRACT FROM AUTHOR]

Background: The thermogenic effects of green tea catechin have been repeatedly reported, but their mechanisms are poorly understood. Objective: The aim of this study was to investigate the acute and chronic effects of catechin on brown adipose tissue (BAT), a site specialized for nonshivering thermogenesis, in humans. Design: Fifteen healthy male volunteers underwent fluorodeoxyglucosepositron emission tomography to assess BAT activity. To examine the acute catechin effect, whole-body energy expenditure (EE) after a single oral ingestion of a beverage containing 615 mg catechin and 77 mg caffeine (catechin beverage) was measured. Next, to investigate the chronic catechin effects, 10 men with low BAT activity were enrolled. Before and after ingestion of the catechin beverage 2 times/d for 5 wk, cold-induced thermogenesis (CIT) after 2 h of cold exposure at 19°C, which is proportional to BAT activity, was examined. Both the acute and chronic trials were single-blinded, randomized, placebo-controlled, season-matched crossover studies. Results: A single ingestion of the catechin beverage increased EE in 9 subjects who had metabolically active BAT (mean ± SEM: +15.24 ± 1.48 kcal, P < 0.01) but not in 6 subjects who had negligible activities (mean ± SEM: +3.42 ± 2.68 kcal). The ingestion of a placebo beverage containing 82 mg caffeine produced a smaller and comparative EE response in the 2 subject groups. Multivariate regression analysis revealed a significant interaction between BAT and catechin on EE (b = 0.496, P = 0.003). Daily ingestion of the catechin beverage elevated mean ± SEM CIT (from 92.0 ± 26.5 to 197.9 ± 27.7 kcal/d; P = 0.009), whereas the placebo beverage did not change it. Conclusion: Orally ingested tea catechin with caffeine acutely increases EE associated with increased BAT activity and chronically elevates nonshivering CIT, probably because of the recruitment of BAT, in humans. These trials were registered at www. umin.ac.jp/ctr/as UMIN000016361. [ABSTRACT FROM AUTHOR]

Cancer has the highest mortality and morbidity rates, and kills more men than women in Japan. Culturally and medically constructed as a 'lifestyle-related disease', prostate cancer incidence is directly proportional to the 'Westernisation of eating habits', and societal ageing. Nevertheless, campaigns to advocate routine testing for prostate cancer remain non-existent. Based on an adaptation of the 'sexual scripts' theorising (Gagnon and Simon, 2005), 21 Japanese urologists from Osaka, Kobe and Tokyo, recruited through snowball sampling, were interviewed from 2021 to 2022, to explore how banal nationalisms in medicine —daily medical practice grounded in cultural scripts concerning the Japanese ethnic-self, rather than in medical 'biological causation to explain illness' (Barry and Yuill, 2008, 20), influence their onco-practice. 'Systemic networks' (Bliss et al., 1983) underpinned the analysis of interviews, which indicates that the physicians tend to (re)produce banal nationalisms in medicine through an understanding of an onco-self , who embodies an 'essentialised' version of the Japanese-self concerning rational-thinking, medical-compliancy, and a dependency on familialism and the feminisation of care to cope with cancer. In grappling with prostate cancer, onco-biopedagogy built on the consumption of traditional Japanese food comprehends banal nationalisms in medicine entrenched in prostate onco-practice. Lastly, endorsing and subsidising Traditional Japanese Medicine encompass an element of onco-economics that involves banal nationalisms in medicine. Nonetheless, emotionality underneath decision-making processes, and an onco-self demanding a robotic surgery challenge the validity of banal nationalisms in medicine when grasping onco-practice. • Prostate onco-practice serves to (re)produce banal nationalisms in medicine. • Endorsing traditional food to prevent cancer nurtures banal nationalisms in medicine. • Essentialisms of the Japanese-self help grasp how banal nationalisms in medicine work. • A Westernised-self is prone to prostate cancer through banal nationalisms in medicine. • Approved use of Japanese Traditional Medicine conveys banal nationalisms in medicine. [ABSTRACT FROM AUTHOR]

Context: Plant-based diets (PBDs) are a healthy alternative to westernized diets. A semivegetarian diet, a PBD, has been shown to prevent a relapse in Crohn disease. However, there is no way to measure adherence to PBDs. Objective: To develop a simple way of evaluating adherence to a PBD for Japanese patients with inflammatory bowel disease (IBD). Design: PBD scores were assigned according to the frequency of consumption provided on a food-frequency questionnaire, obtained on hospitalization for 159 patients with ulcerative colitis and 70 patients with Crohn disease. Eight items considered to be preventive factors for IBD were scored positively, and 8 items considered to be IBD risk factors were scored negatively. The PBD score was calculated from the sum of plus and minus scores. Higher PBD scores indicated greater adherence to a PBD. The PBD scores were evaluated on hospitalization and 2 years after discharge for 22 patients with Crohn disease whose dietary pattern and prognosis were established. Main Outcome Measure: Plant-Based Diet score. Results: The PBD scores differed significantly, in descending order, by dietary type: pro-Japanese diet, mixed type, and pro-westernized diet (Wilcoxon/Kruskal-Wallis test). The PBD scores in the ulcerative colitis and Crohn disease groups were 10.9 ± 9.5 and 8.2 ± 8.2, respectively. For patients with Crohn disease, those with long-term remission and normal C-reactive protein concentration were significantly more likely to have PBD scores of 25 or greater than below 25 (χ²). Conclusion: The PBD score is a valid assessment of PBD dietary adherence. [ABSTRACT FROM AUTHOR]

Background: Green tea is a beverage with potential effects on cognitive dysfunction, as indicated by results of experimental studies. However, its effects in humans, especially at real-world (typical) consumption levels, are unclear.Methods: A double-blind, randomized controlled study was conducted to assess the effects of green tea consumption on cognitive dysfunction (Mini-Mental State Examination Japanese version (MMSE-J) score <28) in Japan. Participants were randomly allocated to the green tea or placebo group, and consumed either 2 g/day of green tea powder (containing 220.2 mg of catechins) or placebo powder (containing 0.0 mg of catechins), respectively, for 12 months. Cognitive function assessments were performed every 3 months using the MMSE-J and laboratory tests.Results: Thirty-three nursing home residents with cognitive dysfunction were enrolled (four men, 29 women; mean age ± SD, 84.8 ± 9.3; mean MMSE-J score ± SD, 15.8 ± 5.4), of whom 27 completed the study. Changes of MMSE-J score after 1 year of green tea consumption were not significantly different compared with that of the placebo group (-0.61 [-2.97, 1.74], least square mean (LSM) difference [95 % CI]; P = 0.59). However, levels of malondialdehyde-modified low-density lipoprotein (U/L), a marker of oxidative stress, was significantly lower in the green tea group (-22.93 [-44.13, -1.73], LSM difference [95 % CI]; P = 0.04).Conclusions: Our results suggest that 12 months green tea consumption may not significantly affect cognitive function assessed by MMSE-J, but prevent an increase of oxidative stress in the elderly population. Additional long-term controlled studies are needed to clarify the effects.Trial Registration: UMIN000011668. [ABSTRACT FROM AUTHOR]

Purpose: Coffee and green tea consumption may be associated with circulating adipokines, but data are inconsistent, scarce or lacking. We examined the association of coffee and green tea consumption with serum adiponectin, leptin, visfatin, resistin and plasminogen activator inhibitor-1 (PAI-1) among a Japanese working population. Methods: The authors analyzed data ( n = 509) from a cross-sectional survey among Japanese workers aged 20-68 years. Serum adipokines were measured using a Luminex suspension bead-based multiplexed array. Coffee and green tea consumption was assessed using a validated diet history questionnaire, and caffeine consumption from these beverages was estimated. Multiple regression analysis was performed with adjustment for potential confounding variables. Results: Coffee consumption was significantly, inversely associated with leptin and PAI-1 ( P for trend = 0.007 and 0.02, respectively); compared with subjects consuming <1 cup per day, those consuming ≥4 cups per day had 13 and 10 % lower means of leptin and PAI-1, respectively. Similar associations were observed for caffeine consumption ( P for trend = 0.02 for both leptin and PAI-1). Additionally, we noted a significant positive association between coffee consumption and adiponectin in men ( P for trend = 0.046), but not in women ( P for trend = 0.43, P for interaction = 0.11). Moreover, there was a positive association between coffee consumption and resistin in current male smokers ( P for trend = 0.01), but not in male non-smokers ( P for trend = 0.35, P for interaction = 0.11). Green tea consumption was not associated with any adipokine. Conclusions: Higher consumption of coffee and caffeine but not green tea was associated with lower serum levels of leptin and PAI-1 in Japanese adults. [ABSTRACT FROM AUTHOR]

In 1950, age-adjusted prostate cancer mortality was 40-fold higher in the US than in Japan. This disparity is not primarily reflective of genetics, as this differential is currently only about 2-fold. The Japanese diet in 1950 was low in protein compared to Western diets, and particularly low in animal protein, a rich source of essential amino acids. Other ecologic epidemiology from 1980 points to prostate cancer mortality being markedly lower in countries with quasi-vegan diets than in those with omnivore diets. Low-protein diets nearly devoid of "high quality" animal protein can be expected to decrease plasma IGF-I, increase plasma levels of adiponectin, and diminish mTORC1 activity – effects that might be expected to lower prostate cancer risk. Hence, the quasi-vegan nature of the Japanese diet ca. 1950 may have contributed importantly to their protection from prostate cancer. But there is reason to suspect that heavy consumption of green tea and regular consumption of soy products rich in isoflavones may have contributed to this protection as well. In any case, it is clearly important to understand why death from what is now the U.S.'s number two cancer killer in males was once extremely rare in Japan. [ABSTRACT FROM AUTHOR]

Background and Objective Keratinization of the oral mucosa, such as the gingiva, has been shown to be important for periodontal health. Caspase-14 is a protease that plays a role in keratinization of the epidermis. The objective of this study was to investigate whether the expression of caspase-14 is intimately linked with keratinization and to examine the effect of the main component of green tea on the improvement of keratinization in rat oral mucosal preparations. Material and Methods Histological and immunohistochemical analyses and quantitative mRNA measurements of caspase-14 and its substrate filaggrin were performed using different types of rat epithelial tissue and organotypic reconstruction culture models derived from epithelial cells and fibroblasts taken from the rat oral mucosa. Results In the skin, palate, buccal mucosa and esophagus, the degree of keratinization appeared to be associated with expression of cytokeratin 10. The relative protein and mRNA expression levels of caspase-14 and filaggrin were consistent with the degree of keratinization in the following order: skin > palate > buccal mucosa > esophagus. The culture models of palatal and buccal mucosa retained a stratified epithelial structure. Expression of caspase-14 appeared to be stronger in the palatal model than in the buccal model. Remarkably, epigallocatechin-3-gallate (EGCG) improved the localization of cytokeratins and increased the expression of caspase-14 and filaggrin. This expression was more intense in the palatal model than in the buccal model, indicating that both models maintain the intrinsic properties of keratinization of the mucosa from where the cultured cells were derived. Conclusions These results suggest that keratinization is closely associated with expression of caspase-14 and filaggrin. Our reconstruction models are promising tools for drug evaluation and show that EGCG is beneficial for improving both keratinization and expression of the linked protease in the oral mucosa. [ABSTRACT FROM AUTHOR]

Elevated postprandial hyperglycaemia and oxidative stress increase the risks of type 2 diabetes and CVD. Green tea catechin possesses antidiabetic properties and antioxidant capacity. In the present study, we examined the acute and continuous effects of ingestion of catechin-rich green tea on postprandial hyperglycaemia and oxidative stress in healthy postmenopausal women. Participants were randomly assigned into the placebo (P, n 11) or green tea (GT, n 11) group. The GT group consumed a catechin-rich green tea (catechins 615 mg/350 ml) beverage per d for 4 weeks. The P group consumed a placebo (catechins 92 mg/350 ml) beverage per d for 4 weeks. At baseline and after 4 weeks, participants of each group consumed their designated beverages with breakfast and consumed lunch 3 h after breakfast. Venous blood samples were collected in the fasted state (0 h) and at 2, 4 and 6 h after breakfast. Postprandial glucose concentrations were 3 % lower in the GT group than in the P group (three-factor ANOVA, group × time interaction, P< 0·05). Serum concentrations of the derivatives of reactive oxygen metabolites increased after meals (P< 0·05), but no effect of catechin-rich green tea intake was observed. Conversely, serum postprandial thioredoxin concentrations were 5 % higher in the GT group than in the P group (three-factor ANOVA, group × time interaction, P< 0·05). These findings indicate that an acute ingestion of catechin-rich green tea has beneficial effects on postprandial glucose and redox homeostasis in postmenopausal women. [ABSTRACT FROM PUBLISHER]

Background and Objective Green tea extract exerts a variety of biological effects, including anti-inflammatory activities. However, there has been no report on the effect of green tea extract on loss of attachment, which is an important characteristic of periodontitis. Here, we examined the inhibitory effects of green tea extract on the onset of periodontitis in a rat model. Material and Methods Rats were immunized intraperitoneally with Escherichia coli lipopolysaccharide ( LPS). The LPS group ( n = 12) received a topical application of LPS onto the palatal gingival sulcus every 24 h. The green tea extract group ( n = 12) received a topical application of LPS mixed with green tea extract, sunphenon BG, every 24 h. The phosphate-buffered saline ( PBS) group ( n = 6) received a topical application of PBS every 24 h. The levels of anti- LPS immunoglobulin G (IgG) in serum were determined using ELISA. Rats in the LPS and green tea extract groups were killed after the 10th and 20th applications. Rats in the PBS group were killed after the 20th application. Loss of attachment, level of alveolar bone and inflammatory cell infiltration were investigated histopathologically and histometrically. RANKL-positive cells and the formation of immune complexes were evaluated immunohistologically. Results There was no significant difference in the serum levels of anti- LPS IgG between the LPS group and the green tea extract group. In contrast, loss of attachment, level of alveolar bone, inflammatory cell infiltration and RANKL expression in the green tea extract group were significantly decreased compared with those in the LPS group. Conclusion These findings demonstrate that green tea extract suppresses the onset of loss of attachment and alveolar bone resorption in a rat model of experimental periodontitis. [ABSTRACT FROM AUTHOR]

ObjectiveTo examine the association between the consumption of green tea, coffee and caffeine and depressive symptoms.DesignCross-sectional study. Consumption of green tea and coffee was ascertained with a validated dietary questionnaire and the amount of caffeine intake was estimated from these beverages. Depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale. Multiple logistic regression analysis was performed to compute odds ratios and 95 % confidence intervals for depressive symptoms with adjustments for potential confounders.SettingTwo workplaces in north-eastern Kyushu, Japan, in 2009.SubjectsA total of 537 men and women aged 20–68 years.ResultsHigher green tea consumption was associated with a lower prevalence of depressive symptoms. Compared with participants consuming ≤1 cup/d, those consuming ≥4 cups green tea/d had a 51 % significantly lower prevalence odds of having depressive symptoms after adjustment for potential confounders, with significant trend association (P for trend = 0·01). Further adjustment for serum folate slightly attenuated the association. Coffee consumption was also inversely associated with depressive symptoms (≥2 cups/d v. <1 cup/d: OR = 0·61; 95 % CI 0·38, 0·98). Multiple-adjusted odds for depressive symptoms comparing the highest with the lowest quartile of caffeine consumption was OR = 0·57 (95 % CI 0·30, 1·05; P for trend = 0·02).ConclusionsResults suggest that higher consumption of green tea, coffee and caffeine may confer protection against depression. [ABSTRACT FROM AUTHOR]

Abstract: Little is known about the relation of modifiable dietary factors to circulating homocysteine concentrations, particularly in young adults and non-Western populations. We investigated the hypothesis that intakes of nutrients and foods are associated with serum homocysteine concentration in a group of young Japanese women. This cross-sectional study included 1050 female Japanese dietetic students aged 18 to 22 years. Dietary intake was assessed using a validated, self-administered, comprehensive diet history questionnaire. Fasting blood samples were collected, and serum homocysteine concentrations were measured. Adjustment was made for survey year, region, municipality level, current smoking, current alcohol drinking, dietary supplement use, physical activity, body mass index, energy intake, and intakes of other nutrients or foods. After adjustment for nondietary confounding factors, intakes of all B vitamins (folate, vitamin B-6, vitamin B-12, and riboflavin) were inversely associated with homocysteine concentration. However, only vitamin B-6 remained significant after further adjustment for other B vitamins. Marine-origin n-3 polyunsaturated fatty acid intake showed an inverse association, but this was not independent of intakes of B vitamins. For foods, pulses, fish and shellfish, and vegetables were independently and inversely associated with homocysteine concentration, but these associations disappeared after adjustment for intakes of other foods. Conversely, an inverse association for dairy products and a positive association for green and oolong tea remained even after adjustment for other foods. To conclude, in a group of young Japanese women, higher intake of vitamin B-6 and dairy products and lower intake of green and oolong tea were independently associated with lower serum homocysteine concentration. [Copyright &y& Elsevier]

Aim: Although previous studies have shown that consumption of green tea catechins (GTC) and walking might prevent development of cardiovascular disease (CVD), the effects of GTC supplementation on CVD risk in active older people are unknown. Methods: A total of 52 older adults (male/female 20/32, mean age 69.1 ± 5.9 years) participating in a pedometer-based walking program were randomly assigned to a GTC group with an intake of 630.9 mg GTC daily ( n = 26) or a control group ( n = 26) for 14 weeks. Cardiovascular risk markers were measured before and after this trial. Results: In the GTC group, values of the following markers were significantly reduced ( P < 0.05) from the beginning to the end of the trial: waist circumference (from 84.2 ± 8.4 to 82.2 ± 8.5 cm), hip circumference (from 95.1 ± 6.9 to 92.2 ± 6.3 cm), total cholesterol (from 233.0 ± 46.3 to 218.8 ± 42.3 mg/dL), low-density lipoprotein cholesterol (from 130.4 ± 36.2 to 119.1 ± 33.4 mg/dL) and low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (from 2.0 ± 1.7 to 1.7 ± 0.5); only hip circumference (from 95.6 ± 8.1 to 94.1 ± 7.6 cm) was significantly reduced ( P < 0.05) in the control group. No significant between-group differences were found for any parameter measured. Conclusions: Although GTC might reduce cholesterol levels, the present randomized control trial suggests that GTC supplementation in active older participants did not significantly affect cardiovascular risk markers. Future studies should identify more effective combinations of GTC supplementation and physical activity. Geriatr Gerontol Int 2013; 13: 622-629. [ABSTRACT FROM AUTHOR]

Abstract: Certain foodstuffs exhibit matrix interference effects on the vitamin B1 analysis prescribed in the official methods of the European Union, AOAC International, and Japan. In this study, we demonstrated that one of the problematic polyphenols in green tea or cocoa was tannin. For these matrices, thiamine was found to interact with tannin in the extraction step and was thus removed by filtration as a residue. To resolve the matrix interference, we proposed lowering the pH of the extraction solution by adding hydrochloric acid after the enzyme reaction. High precision (2–3% RSDr) and good recovery (98.3–103%) were obtained with reference materials using the proposed method. We also confirmed the equivalence of the obtained data from the proposed method and the Japanese official method for nutritional labeling. From these results, the method was found to be effective for vitamin B1 analysis regardless of the presence of interference matrices. [Copyright &y& Elsevier]

Abstract: Green tea is now an acknowledged cancer preventive in Japan. Based on evidence that colorectal adenomas and prostate cancer in humans have been prevented, we review here the concept that the combination of anticancer drugs with green tea catechin synergistically induces apoptosis of human cancer cells, inhibits tumor formation in mice, and enhances inhibition of tumor growth in xenograft mouse models. As a molecular mechanism by the combination, the induction of growth arrest and DNA damage-inducible 153 (GADD153, CHOP) gene expression is discussed in relation to death receptor 5 and TRAIL-apoptotic pathway. The combination of anticancer drugs with green tea could be a new cancer therapeutic strategy in humans. [Copyright &y& Elsevier]

Background: Green tea has shown the role of chemoprevention for cancer. Recently, several studies suggested that green tea intake may have effect on esophageal cancer risk, whereas the results were inconsistent. Methods: We performed a meta-analysis of all English and Chinese language studies of green tea consumption and esophageal cancer risk indexed in Medline, Embase, the Science Citation Index, the Chinese Biomedical Database and Wanfang Data from 1980 to June 2012. After reviewing each study, extracting data, and evaluating heterogeneity (Chi-square-based Q test and I²) and publication bias (Begg and Egger test), a meta-analysis was performed to evaluate the association between high/medium/low green tea consumption and non-drinking esophageal cancer risk. Pooled relative risk (RR) or odds ratio (OR) with 95% confidence intervals (CIs) were calculated using the fixed- or random-effect models. Results: Ten eligible epidemiologic studies including 33731 participants and 3557 cases for esophageal cancer were included. Eight of which were case-control studies, and two were cohort studies. Overall, there were no association between high/medium/low green tea consumption and non-drinking risk of esophageal cancer (High: highest vs non-drinker: RR/OR = 0.76, 95% CI: 0.49 to 1.02. Medium: drinker vs non-drinker: RR/OR = 0.86, 95% CI: 0.70 to 1.03. Low: lowest vs non-drinker: RR/OR = 0.83, 95% CI: 0.58 to 1.08). When stratified analyses according to study design (case-control and cohort studies), country (China and Japan), participates source (population-based and hospital-based case-control), and gender (female and male), there were significant association between high/medium/low green tea consumption and non-drinking risk of esophageal cancer among female (High: RR/OR = 0.32, 95% CI: 0.10 to 0.54. Medium: RR/OR = 0.43, 95% CI: 0.21 to 0.66. Low: RR/OR = 0.45, 95% CI: 0.10 to 0.79), but not the others. Conclusions: We did not found significant association between green tea consumption and non-drinking esophageal cancer risk, but an evidence of protective effect was observed among female. [ABSTRACT FROM AUTHOR]

Background: Previous studies have reported that green tea consumption is associated with a lower risk of diseases that cause functional disability, such as stroke, cognitive impairment, and osteoporosis. Although it is expected that green tea consumption would lower the risk of incident functional disability, this has never been investigated directly. Objective: The objective was to determine the association between green tea consumption and incident functional disability in elderly individuals. Design: We conducted a prospective cohort study in 13,988 Japanese individuals aged ≥65 y. Information on daily green tea consumption and other lifestyle factors was collected via questionnaire in 2006. Data on functional disability were retrieved from the public Long- term Care Insurance database, in which subjects were followed up for 3 y. We used Cox proportional hazards regression analysis to investigate the association between green tea consumption and functional disability. Results: The 3-y incidence of functional disability was 9.4% (1316 cases). The multiple-adjusted HR (95% CI) of incident functional disability was 0.90 (0.77, 1.06) among respondents who consumed 1-2 cups green tea/d, 0.75 (0.64, 0.88) for those who consumed 3-4 cups/d, and 0.67 (0.57, 0.79) for those who consumed ≥5 cups/d in comparison with those who consumed <1 cup/d (P-trend < 0.001). Conclusion: Green tea consumption is significantly associated with a lower risk of incident functional disability, even after adjustment for possible confounding factors. [ABSTRACT FROM AUTHOR]

Green tea is known to contain antiviral components that prevent influenza infection. A limited number of adult clinical studies have been undertaken, but there is a paucity of clinical evidence concerning children. We conducted an observational study to determine the association between green tea consumption and the incidence of influenza infection among schoolchildren. Anonymous questionnaire surveys were undertaken twice during the influenza season from November 2008 to February 2009 (endemic seasonal type A influenza infection); each survey was conducted for 2663 pupils across all elementary schools in Kikugawa City (a tea plantation area), Japan. Each questionnaire was completed and submitted by 2050 pupils (response rate, 77.0%; age range, 6-13 y). The adjusted OR associated with the consumption of green tea for ≥6 d/wk compared with <3 d/wk was 0.60 [(95% Cl = 0.39-0.92); P= 0.021 in cases of influenza confirmed by the antigen test. Meanwhile, the adjusted OR inversely associated with the consumption of 1 cup/d to <3 cups/d (1 cup = 200 mL( and 3-5 cups/d compared with <1 cup/d were 0.62 [(95% Cl = 0.41-0.95); P = 0.031 and 0.54 [(95% Cl = 0.30- 0.94); P = 0.031, respectively. However, there was no significant association with the consumption of >5 cups/d. Our findings thus suggest that the consumption of 1-5 cups/d of green tea may prevent influenza infection in children. [ABSTRACT FROM AUTHOR]

Purpose: Coffee is among the most widely consumed beverages in the world. Numerous epidemiological studies have reported a significant inverse association between coffee consumption and risk of type 2 diabetes mellitus, but the underlying mechanisms are still not fully understood. Therefore, we conducted an epidemiological study to clarify the relationship between coffee consumption and adiponectin levels in Japanese males. We also evaluated whether green tea consumption affected adiponectin levels. Methods: We carried out a cross-sectional study. The subjects were 665 male employees in Japan. Coffee consumption was assessed, using a self-administered questionnaire, as the number of times per week and cups per day respondents drank, and subjects were grouped into four levels (non, 1-5 times/week, 1-2 cups/day and ≥3 cups/day). Results: The means of adiponectin levels were positively associated with coffee consumption. A dose-response relationship was found between coffee consumption and circulating adiponectin levels. The relationship remained significant after adjustment for potential confounding factors ( P for trend <0.05). However, green tea consumption was not significantly associated with adiponectin levels ( P for trend = 0.90). Conclusions: We not only revealed that habitual coffee consumption is associated with higher adiponectin levels in Japanese males but also found a dose-dependent association between coffee consumption and adiponectin levels. Therefore, our study suggested that coffee components might play an important role in the elevation of adiponectin level. [ABSTRACT FROM AUTHOR]

The article focuses on the history and health benefits of tea. According to archaeological evidence, tea was first consumed in the early paleolithic period. It says that tea drinking became part of daily life in Japan and Korea, and the British successfully grew tea in India by the mid-19th century. It also mentions several health benefits of tea as revealed through research including cancer prevention, ultraviolet (UV) protection, and weight loss.

Folate is a vital nutrient during pregnancy for the prevention of neural tube defects, intrauterine fetal growth restriction and preeclampsia. Circulating folate levels might be negatively affected by (-)-epigallocatechin gallate, which is a tea catechin found in green tea and oolong tea. The aim of this study was to determine whether consumption of green tea or oolong tea was associated with circulating folate levels among pregnant women in Japan. Two hundred and fifty-four healthy women with a singleton pregnancy (age: 30.4 ± 4.7, gestational age: 27.5 ± 9.6 weeks) were recruited from a prenatal clinic in metropolitan Tokyo, Japan. The serum folate levels were measured. Nutrient intake was assessed using a self-administered diet history questionnaire. Information on lifestyle variables was obtained from the questionnaire. The high consumption of green tea or oolong tea was defined as consumption more than 57.3 mL per 1,000 kcal, which is the 75th percentile of participants. The serum folate levels of the participants with high consumption of green tea or oolong tea was significantly lower than those of others (p = 0.027). A multiple regression analysis revealed the high consumption of green tea or oolong tea to be associated with a low serum folate level during pregnancy, after adjusting for confounding variables including dietary folate intake and use of folic acid supplements or multivitamins (β = -0.131, p = 0.016). The association between folate and the consumption of green tea or oolong tea may be useful to clarify the mechanism which links adverse perinatal outcomes and tea consumption. [ABSTRACT FROM AUTHOR]

Background: Circulating high-sensitivity C-reactive protein (CRP) is a good marker of chronic low-grade inflammation. The few studies that have addressed the relationship between coffee consumption and CRP concentrations report inconsistent findings. The authors of this study examined the relationship between coffee and green tea consumption and serum concentrations of CRP, and the interaction with alcohol consumption, smoking, and obesity in a large population of free-living Japanese men and women. Methods: Study subjects were 10,325 men and women, 49–76 years of age, living in Fukuoka City who participated in a baseline survey of a cohort study on lifestyle-related diseases. Coffee and green tea consumption and other lifestyle characteristics were assessed using a structured questionnaire. Anthropometric measurements and venous blood samples were also included. Results: CRP concentrations were progressively lower with increasing levels of coffee consumption, after adjustment for smoking and other covariates (p for trend=0.03) in men, but not in women. Stratified analysis indicated that this inverse association was primarily limited to men with a high consumption of alcohol (≥50 g/day). Green tea consumption showed no measurable relationship with CRP concentrations in either men or women. Conclusions: Coffee may be protective specifically against alcohol-induced hepatic inflammation. Further studies are warranted in different populations. Clin Chem Lab Med 2010;48:849–54. [ABSTRACT FROM AUTHOR]

Several biologic studies have reported that green tea constituents have antitumor effects on hematologic malignancies. However, the effects in humans are uncertain. The authors used data from the Ohsaki National Health Insurance Cohort Study in Japan to evaluate the association between green tea consumption and the risk of hematologic malignancies. Study participants were 41,761 Japanese adults aged 40–79 years without a history of cancer at baseline who answered a food frequency questionnaire survey in 1994. During 9 years of follow-up beginning in 1995, the authors documented 157 hematologic malignancies, including 119 cases of lymphoid neoplasms and 36 cases of myeloid neoplasms. Hazard ratios were calculated by using the Cox proportional hazards regression model. Risk of hematologic malignancies was inversely associated with green tea consumption. The multivariate-adjusted hazard ratio of hematologic malignancies for 5 cups/day or more compared with less than 1 cup/day of green tea was 0.58 (95% confidence interval: 0.37, 0.89). The corresponding risk estimate was 0.52 (95% confidence interval: 0.31, 0.87) for lymphoid neoplasms and 0.76 (95% confidence interval: 0.32, 1.78) for myeloid neoplasms. This inverse association was consistent across sex and body mass index strata. In conclusion, green tea consumption was associated with a lower risk of hematologic malignancies. [ABSTRACT FROM PUBLISHER]

This paper describes the application of the common and variation peak ratio dual-index sequence analysis methods to evaluate the quality of several tea samples obtained from different species and different areas based on 1HNMR fingerprint spectra (FPS). The method is able to determine the most similar sample groups and identify accurately the varieties and qualities of Blank tea, Longjing tea, and other green tea samples. Longjing tea is a famous brand of local green tea and has its own distinct characteristics. There were obvious differences between Uji tea from Japanese and Chinese green tea. The results showed that the dual index sequent analytical method provides a good approach to accurately describe the resemblance and differences among tea samples. It also can reflect tea's integrity and individual difference, and is an effective method to evaluate the quality of tea samples. [ABSTRACT FROM AUTHOR]