Search

Cognitive disorders have emerged as an important public health problem among older adults in China. Cohort studies investigating the relationship between tea consumption, various cognitive functions, and mental health have exhibited limited evidence and inconsistent findings. The present study aimed to explore the associations between these variables among community-dwelling Chinese older adults. Analysis of covariance (ANCOVA) was used to compare scores on cognitive functions among green tea-consumers (GTC), other types of tea consumers (OTC), and non-tea-consumers (NTC), after adjusting for gender, education, residence, drinking, smoking, and hobbies. Thereafter, binary logistic regression analysis was applied to evaluate the role of tea consumption in differentiating between patients with mild cognitive impairments (MCI) and the controls without impairment. Among 972 participants, green tea consumption was significantly associated with improved performance on global cognitive function except for mental health assessments. In contrast to NTC, reduced risk of cognitive impairment was observed for both GTC and OTC after adjusting for demographic, lifestyle, and body health indicators. Furthermore, a significant correlation was found between tea consumption and improved cognitive performance. Thus, tea consumption played an important role in distinguishing older adults with mild cognitive impairment from older adults without cognitive impairment. [ABSTRACT FROM AUTHOR]

aimed to explore the interaction between harmful alcohol use and tea consumption on hyperuricemia. Methods: This study recruited 22,449 Han residents based on the data from the China Multi-Ethnic Cohort (CMEC) study, Chongqing province, to have a face-to-face electronic questionnaire, physical examination, and clinical laboratory tests. The difference in hyperuricemia between the different populations was compared by the Chi-square test. The interaction between harmful alcohol use and tea consumption was analyzed by the multivariate logistic regression model. Results: Amongst 22,449 participants, the mean age was 51.5± 11.8 years, and 46.83% of them were males. The proportion of harmful alcohol use, tea consumption, and harmful alcohol use and tea consumption were 14.01%, 21.01%, and 6.54%, respectively. Multivariate logistic regression showed that the odds ratio (OR) of harmful alcohol use and tea consumption (OR=2.21, 95% CI: 1.58– 3.10) was greater than that of harmful alcohol use (OR=1.63, 95% CI:1.17– 2.27) and tea consumption (OR=1.34, 95% CI:1.10– 1.63). Among males, the results were similar (harmful alcohol use and tea consumption: OR=2.02, 95% CI: 1.43– 2.84; harmful alcohol use: OR=1.61, 95% CI: 1.14– 2.27; tea consumption: OR=1.28, 95% CI: 1.05– 1.57). However, among females, the odds ratio of harmful alcohol use and tea consumption (OR=15.50, 95% CI: 1.36– 176.50) was more than 10 times than that of only harmful alcohol use (OR=1.55, 95% CI: 0.42– 5.69) or tea consumption (OR=1.22, 95% CI: 0.52– 2.82). Conclusion: The interaction of harmful alcohol use and tea consumption was a positive risk for hyperuricemia in Han residents aged 30– 79 years in China. [ABSTRACT FROM AUTHOR]

Background: Existing limited evidence suggests that smoking and tea consumption may be associated with a lower risk of Parkinson's disease (PD). However, less is known about the independent and joint roles of these two habits, which are often clustered among Chinese, on PD risk. Objective: To prospectively examine the independent and joint association of tea consumption and smoking with the risk of PD. Methods: The China Kadoorie Biobank (CKB) study recruited 512,725 participants aged 30 to 79 years from ten areas across China since 2004. Information on smoking and tea consumption was collected at baseline, and PD cases were ascertained by linkage to the national health insurance system and death registry. Cox proportional hazards models were used to estimate the multivariable-adjusted hazard ratios (HRs) and corresponding 95%confidence intervals (CIs). Results: During a median of 10.8 years of follow-up, 922 PD cases were recorded. Compared with participants who never consumed tea, the HR (95%CI) for daily consumers was 0.68 (0.55, 0.84). Compared with participants who never or occasionally smoked, the HR (95%CI) for current smokers was 0.66 (0.53, 0.82). Those who had a clustering habit of smoking and tea consumption had a 38%(HR = 0.62; 95%CI: 0.49, 0.79) lower PD risk than those who consumed none. However, there were no statistically significant multiplicative or additive interaction for tea consumption and smoking on PD risk. Conclusion: We found that smoking and daily tea consumption were independently inversely associated with the risk of PD. [ABSTRACT FROM AUTHOR]

Background: The effect of tea consumption on metabolic syndrome (MetS) remains controversial. The objective of this study is to examine the prospective association of tea consumption with 5-year incident MetS among aged population in China. Methods: This analysis included 3005 Chinese adults aged 60 years or older who were free of MetS at baseline examination. MetS was defined according to the National Cholesterol Education Program-Adult Treatment Panel III. Information regarding tea consumption was collected via an interviewer-administrated questionnaire. The prospective associations between tea consumption at baseline and 5-year incident MetS, as well as its individual components, were assessed by multiple logistic regression models. Results: Of the 3005 participants free of MetS at baseline, 406 participants (cumulative incidence: 13.5%) developed MetS at the 5-year follow-up examination. In multiple logistic regressions, 5-year cumulative incidence of MetS was found to be higher in those who drank tea more than 5 times per week as compared with non-habitual drinkers (OR = 1.38, 95% CI: 1.05-1.82; P = 0.02). This relationship still existed in men (OR = 1.43, 95%CI: 1.00-2.01; P = 0.05) when stratified by gender. Among the five major components of MetS, low high-density lipoprotein cholesterol was observed in men, while high body mass index, elevated blood pressure and the presence of diabetes mellitus were significant in women. Conclusions: High-frequent tea consumption increased the risk of MetS among older Chinese adults. These findings may add novel knowledge to the current studies regarding the controversial effect of tea consumption on cardiovascular and metabolic health among the aged population. [ABSTRACT FROM AUTHOR]

Background Evidence from epidemiological studies remains inconsistent or limited about the associations of tea consumption with incident diabetes and risk of diabetic complications and death among patients with diabetes. Objectives We aimed to investigate the associations of tea consumption with long-term risk of developing type 2 diabetes (T2D) and risks of diabetic complications and death among patients with diabetes. Methods This study included 482,425 diabetes-free participants and 30,300 patients with diabetes aged 30–79 y at study enrollment from the China Kadoorie Biobank. Tea consumption information was collected at baseline by interviewer-administered questionnaires. Incidences of diabetes, diabetic complications, and death were identified by linkages to the National Health Insurance system, disease registries, and death registries. Cox proportional hazard regression models were used to estimate HRs and 95% CIs. Results The mean ± SD age of participants free of diabetes was 51.2 ± 10.5 y and 41% were male. The mean ± SD age of patients with diabetes was 58.2 ± 9.6 y and 39% were male. Of all daily tea consumers, 85.8% preferred green tea. In the diabetes-free population, 17,434 participants developed incident T2D during 11.1 y of follow-up. Compared with participants who never consumed tea in the past year, the HR (95% CI) of T2D for daily consumers was 0.92 (0.88, 0.97). In patients with diabetes, we identified 6572 deaths, 12,677 diabetic macrovascular cases, and 2441 diabetic microvascular cases during follow-up. Compared with patients who never consumed tea in the past year, the HRs (95% CIs) of all-cause mortality and risk of microvascular complications for daily consumers were 0.90 (0.83, 0.97) and 0.88 (0.78, 1.00), respectively. Tea consumption was not associated with risk of macrovascular complications among patients with diabetes. With regard to tea consumed, the inverse associations between daily tea consumption and risks of T2D and all-cause mortality in patients with diabetes were only observed among daily green tea drinkers. Conclusions In Chinese adults, daily green tea consumption was associated with a lower risk of incident T2D and a lower risk of all-cause mortality in patients with diabetes, but the associations for other types of tea were less clear. In addition, daily tea consumption was associated with a lower risk of diabetic microvascular complications, but not macrovascular complications. [ABSTRACT FROM AUTHOR]

The aim of the present study was to explore the influence of tea consumption on diabetes mellitus in the Chinese population. This multi-centre, cross-sectional study was conducted in eight sites from south, east, north, west and middle regions in China by enrolling 12 017 subjects aged 20–70 years. Socio-demographic and general information was collected by a standardised questionnaire. A standard procedure was used to measure anthropometric characteristics and to obtain blood samples. The diagnosis of diabetes was determined using a standard 75-g oral glucose tolerance test. In the final analysis, 10 825 participants were included and multiple logistic models and interaction effect analysis were applied for assessing the association between tea drinking with diabetes. Compared with non-tea drinkers, the multivariable-adjusted OR for newly diagnosed diabetes were 0·80 (95 % CI 0·67, 0·97), 0·88 (95 % CI 0·71, 1·09) and 0·86 (95 % CI 0·67, 1·11) for daily tea drinkers, occasional tea drinkers and seldom tea drinkers, respectively. Furthermore, drinking tea daily was related to decreased risk of diabetes in females by 32 %, elderly (>45 years) by 24 % and obese (BMI > 30 kg/m2) by 34 %. Moreover, drinking dark tea was associated with reduced risk of diabetes by 45 % (OR 0·55; 95 % CI 0·42, 0·72; P < 0·01). The results imply that drinking tea daily was negatively related to risk of diabetes in female, elderly and obese people. In addition, drinking dark tea was associated with decreased risk of type 2 diabetes mellitus. [ABSTRACT FROM AUTHOR]

Background Many cohort studies have explored the relation between tea consumption and stroke risk; however, the conclusions have been inconsistent. In addition, evidence is lacking in China, where the patterns of tea consumption and main types of tea consumed differ substantially from those in high-income countries. Objective We aimed to systematically assess the association of tea consumption with the risk of stroke based on a Chinese large-scale cohort study. Methods A total of 487,377 participants from the China Kadoorie Biobank were included in the present study. Detailed information about tea consumption (including frequency, duration, amount, and tea type) was self-reported at baseline. After ∼4.3 million person-years of follow-up, 38,727 incident cases of stroke were recorded, mainly through linkage with mortality and morbidity registries and based on the national health insurance system. Results Overall, 128,280 adults (26.3%) reported drinking tea almost daily (41.4% men, 15.9% women), predominantly green tea (86.7%). Tea consumption had an inverse and dose–response relation with the risk of stroke (P trend < 0.001). Compared with nonconsumers, those who consumed tea occasionally, weekly, and daily had adjusted HRs and 95% CIs of 0.96 (0.94, 0.99), 0.94 (0.90, 0.98), and 0.92 (0.89, 0.95) respectively, with little difference by stroke type. Among those who consumed tea daily, the HRs for stroke decreased with the increasing duration and amount of tea consumed (all P  < 0.001). These inverse associations were significant for green tea but not for other types of tea. Among men, but not women, the inverse relations could be detected, and similar inverse associations could be found for male noncurrent alcohol-consumers and noncurrent smokers as well. Conclusions Among Chinese adults, higher consumption of tea, especially green tea, was associated with a lower risk of ischemic and hemorrhagic stroke. [ABSTRACT FROM AUTHOR]

To investigate the association between habitual tea consumption and transitions between frailty states among older adults in China. A prospective cohort study based on the Chinese Longitudinal Healthy Longevity Study. A total of 23,720 older adults aged ≥65 years with complete data regarding frailty status and tea consumption were recruited. The frequency and consistency of tea consumption were introduced to evaluate levels of tea consumption. The frailty index was used to define frailty status (frail and nonfrail). Frailty transition was classified into remaining nonfrail, improvement, worsening, and remaining frail groups. Logistic regression models were applied. The overall frailty prevalence at baseline was 19.1%, being lower among consistent daily tea drinkers (12.5%) and higher among non-tea drinkers (21.9%). Logistic regression analyses showed that the risk of frailty was significantly reduced among consistent daily tea drinkers after adjusting for all confounders [odds ratio (OR), 0.81; 95% CI, 0.67–0.98]. During the 3-year follow-up, improvement in frailty status was more common among consistent daily tea drinkers (50.9%) than non-tea drinkers (40.9%), and this trend was opposite in participants with worsened frailty status (consistent daily tea drinkers: 12.2%) vs non-tea drinkers: 19.2%). Further analysis showed that consistent daily tea drinkers were significantly associated with improvement in frailty status (OR, 3.24; 95% CI, 1.02–10.31) and remaining in a nonfrail state (OR, 1.35; 95% CI, 1.00–1.83). In addition, daily tea consumption was observed to be positively associated with remaining in a nonfrail state and inversely associated with worsened frailty status in men, but not in women. Older people consuming tea daily tend to have an improved frailty status in the future. Men with daily tea consumption were less likely to have a worsened frailty status. Advocating for the traditional lifestyle of drinking tea could be a promising way to advance healthy aging for older adults. [ABSTRACT FROM AUTHOR]

Background: As the global population ages, cognitive impairment (CI) becomes more prevalent. Tea has been one of the most popular drinks in the world. Several studies have demonstrated that tea consumption has an impact on cognitive function., Objective: This study aims to examine the association between tea consumption and cognitive function and explore the potential effect of genetics on the relationship between tea consumption and CI risk in older adults., Design: This is a prospective longitudinal study using data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS)., Setting: Six waves of data from CLHLS containing 76,270 subjects were analyzed. Generalized estimation equations (GEE) with a logit link function were adopted to estimate the effect of tea consumption on CI risk from a cross-sectional and longitudinal perspective., Participants: A population-based cohort of adults aged 65-105 years., Measurements: The frequency and type of tea consumption were obtained by questionnaires. CI was measured based on MMSE. Polygenic risk was measured using the polygenic score approach described by the International Schizophrenia., Results: The results showed that drinking green tea had a better protective effect on cognitive function than other types of tea, the incidence of CI gradually decreased with the increase of tea consumption frequency, and men were more likely to benefit from tea consumption. Additionally, we also found a significant interaction between tea consumption and genetic risk, measured by polygenic risk score (PRS)., Conclusions: Based on current research evidence, tea consumption, may be a simple and important measure for CI prevention., Competing Interests: The authors have no relevant financial or non-financial competing interests to declare with this manuscript.

Objective: To explore the association between tea consumption and cognitive impairment (CoI). Methods: 4579 adults (≥60 years) from the Weitang Geratric Diseases Study were assessed for characteristics of tea consumption and cognitive function by administering questionnaires and the Abbreviated Mental Test (AMT), respectively. We divided the subjects into normal cognitive function group (AMT score ≥8) and CoI group (AMT score ≤7).   The association between tea consumption and risk of CoI was determined by logistic regression models. Results: The least-squared means of the AMT scores for the subjects who seldom consumed tea were less favorable than those who habitually consumed tea. An inverse association was found between tea consumption (of any type) and prevalence of CoI (odds ratio = 0.74, 95% confidence interval = 0.57-0.98, P = 0.032). Interestingly, the protective correlation of tea was more obvious in never smokers (odds ratio = 0.63), but vanished in current/former smokers (odds ratio = 1.10). In never smokers, frequency of tea consumption was significantly associated with CoI (P for trend = 0.010). Conclusion: Habitual tea consumption is suggested to be associated with a decreased risk of CoI among elders in Suzhou, and a higher frequency of tea consumption was associated with a lower prevalence of CoI among never smokers. [ABSTRACT FROM AUTHOR]

Objectives: Previous studies found that tea consumption was related to a reduction in the risks of some chronic diseases, but limited data are available on bone health. This study aimed to examine the associations of tea consumption with hip bone strength in Chinese women.Design: Cross-sectional study.Setting: The participants were from the ongoing Guangzhou Nutrition and Health Study. This was a cohort study started in 2008. The examination data conducted between June 2010 and December 2013 were used.Participants: A total of 1,495 Chinese women aged more than 40 years were included.Measurements: Tea consumption, sociodemographic information and lifestyle habits were collected by a face-to-face questionnaire. Hip bone mineral density (BMD) and geometric parameters, i.e. cross-sectional area (CSA), section modulus (Z) and buckling ratio (BR), were generated by dual-energy X-ray absorptiometry. The associations of tea consumption with bone phenotypes were detected by analysis of covariance and multiple linear regression models after adjusting for age, body mass index, years since menopause, physical activity, dietary-protein intake, dietary-calcium intake, calcium tablet intake, drinking status and smoking status.Results: Tea drinkers (n = 732) had approximately 1.9% higher BMD (p < 0.05) and 3.6% lower BR (p < 0.05) than non-tea drinkers (n = 763). The dose-response relationships of BMD, BR or CSA with total tea consumption were identified (p-trend < 0.05). Tea drinking was found to be a significant and independent predictor of BMD (β = 0.068, p < 0.05) or BR (β = -0.079, p < 0.05).Conclusion: Tea consumption was associated with increased bone strength in middle-aged and elderly Chinese women. [ABSTRACT FROM AUTHOR]

Objectives: Tea has long been hypothesized to possess hypotensive effects. However, there is uncertainty regarding the association of tea consumption with arterial blood pressure (BP). We aimed to examine the association between tea consumption and BP components including systolic BP (SBP) and diastolic BP (DBP). Design: Community-based, cross-sectional study of Suzhou City, Jiangsu Province, China. Setting: Tea consumption has protective influence on BP and presence of hypertension. Participants: 4579 older adults aged 60 years or older from the Weitang Geriatric Diseases study. Measurements: Detailed information regarding tea consumption was collected using a pre-designed questionnaire. BP components were measured at least 3 times with a minimum 5-minute interval, by well-trained research nurses. Methods: Data of 4579 older adults (response rate: 82%) aged 60 years or older from the Weitang Geriatric Diseases study were included in the analysis and we estimated the relationship of tea consumption and BP using linear regression models and the association between tea consumption and risk of hypertension using logistic regression models. Results: In linear regression models, higher tea consumption frequency was found to be associated with lower systolic BP values, after adjusting for the effect of age, sex, education level, lifestyle-related factors, and cardiometabolic confounding factors in overall (coefficient =-1.49, P=0.0003), normotensive (coefficient =-0.91, P=0.017) and participants without anti-hypertensive treatment (coefficient =-1.26, P=0.027). Significant inverse association between diastolic BP and frequency of tea consumption was also observed in the overall subjects (coefficient =-0.74, P=0.003). In multivariate logistic analyses, habitual tea drinking was inversely associated with presence of hypertension [odds ratio (OR)=0.79, P=0.011], and there was a progressive reduction in risk associated with higher frequency of tea consumption (P for trend=0.011). Conclusion: Habitual tea consumption was found to be associated with lower values of components of BP and a reduced likelihood of having hypertension in older adults. Given the widespread consumption of tea throughout China and the world, together with the major cardiovascular disease risk, our findings have important implications for human health. [ABSTRACT FROM AUTHOR]

Background: Although tea consumption has been reported to have various health benefits in humans, its association with health-related quality of life (HRQOL) has not been investigated directly. We aimed to examine the relationship between tea consumption and HRQOL among older Chinese adults. Methods: We analyzed community-based cross-sectional data of 5,557 older Chinese individuals aged 60 years or older who participated in the Weitang Geriatric Diseases study. Information on tea consumption and HRQOL assessed by the European Quality of Life-5 dimensions (EQ-5D) were collected by questionnaires. We estimated the relationship of tea consumption and the EQ-5D index score using linear regression models and the association between tea consumption and self-reported EQ-5D health problems using logistic regression models. Results: The EQ-5D index score was higher for habitual tea drinkers than their counterparts. In multivariate linear analyses controlling for socio-demographic conditions, health conditions, and lifestyle habits, the differences in ED-5D index score between individuals with and without tea drinking habits was 0.012 (95% confidence interval, 0.006-0.017). In multivariate logistic analyses, habitual tea drinking was inversely associated with reporting of problems in EQ-5D dimensions mobility (odds ration [OR], 0.44; 95% CI: 0.23-0.84); pain/discomfort (OR, 0.74; 95% CI: 0.61-0.90); and anxiety/depression (OR, 0.60; 95% CI: 0.38-0.97). These associations were more evident for black or oolong tea than green tea. Conclusion: Habitual tea consumption was associated with better HRQOL in older adults. [ABSTRACT FROM AUTHOR]

In middle-aged and elderly individuals, the relationship between tea consumption and incident metabolic syndrome (MetS) is still unclear. Therefore, this study intends to figure out the relationship between tea-drinking frequency and MetS in rural middle-aged and older Chinese residents. In the Northeast China Rural Cardiovascular Health Study, 3632 middle-aged or older individuals (mean age 57 ± 8, 55.2% men) without MetS were included at baseline during 2012-2013 and were followed up on between 2015-2017. Participants showing differential tea consumption frequency were divided into the following classes: non-habitual tea drinkers, occasional tea drinkers, 1-2 times/day drinkers, and ≥3 times/day drinkers. Data showed that non-habitual tea drinking was more common among women. The frequency of tea consumption was higher in ethnic groups other than Han and among singles, as well as in concurrent smokers and drinkers and individuals with primary or lower educational status. The increasing tea consumption was in line with baseline elevations in body mass index, systolic and diastolic blood pressure, high-density lipoprotein cholesterol (HDL-C), and AST/ALT ratio. Multivariate logistic regression analysis confirmed that occasional tea drinking increased the incidence of low HDL-C [OR (95% CI): 1.268 (1.015, 1.584)], high waist circumference [OR (95% CI): 1.336 (1.102, 1.621)], and MetS [OR (95% CI): 1.284 (1.050, 1.570)]. In addition, 1-2 times/day tea drinking increased the cumulative incidence of high TG [OR (95% CI): 1.296 (1.040, 1.616)], high waist circumference [OR (95% CI): 1.296 (1.044, 1.609)] and MetS [OR (95% CI): 1.376 (1.030, 1.760)]. We demonstrated that regular tea consumption is correlated with a greater incidence of metabolic disorders and MetS. Our findings may help clarify the contradictory association reported between tea drinking and MetS development in middle-aged and older residents of rural China.

Objectives: Prior research on the effect of tea consumption on blood pressure (BP) generated inconsistent findings. The objective of this study was to explore the effects of different types of tea consumption on BP., Methods: We included 76,673 participants aged 30-79 from the baseline data of the China Multi-Ethnic Cohort (CMEC) study. Binary logistic regression was used to analyze the influences of different types of tea consumption on the risk of hypertensive BP. Moreover, multiple linear regression was used to examine the association between tea drinking and BP., Results: Tea consumption was associated with a reduced risk of hypertensive BP by 10% (AOR: 0.90, 95%CI: 0.86-0.94). While dark tea was related to a 1.79-5.31 mmHg reduction in systolic blood pressure (SBP) and a 0.47-1.02 mmHg reduction in diastolic blood pressure (DBP), sweet tea, regardless of the duration, frequency, or amount of consumption, significantly was associated with a reduced SBP by 3.19-7.18 mmHg. Green tea also was associated with a reduced SBP by 1.21-2.98 mmHg. Although scented tea was related to reduced SBP by 1.26-2.48 mmHg, the greatest effect came from the long duration (> 40 years:β=-2.17 mmHg, 95%CI=-3.47 mmHg --0.87 mmHg), low frequency (1-2 d/w: β = -2.48 mmHg, 95%CI=-3.76 mmHg--1.20 mmHg), and low amount (≤ 2 g/d: β=-2.21 mmHg, 95%CI=-3.01 mmHg--1.40 mmHg). Additionally, scented tea was correlated to a decrease in DBP at the frequency of 1-2 d/w (β=-0.84 mmHg, 95%CI=-1.65 mmHg--0.02 mmHg). Drinking black tea only was associated with lowered SBP. The protective effect of black tea on SBP was characterized by the long-duration (> 15 years, -2.63--5.76 mmHg), high frequency (6-7 d/w, -2.43 mmHg), and medium amount (2.1-4.0 g/d, -3.06 mmHg)., Conclusion: Tea consumption was associated with lower SBP and a reduced risk of hypertensive BP. The antihypertensive effect varies across types of tea consumed., (© 2023. The Author(s).)

Background: Epidemiological studies suggest that higher tea consumption was associated with lower risk of depressive symptoms, but this has not been found consistently. Moreover, the effect of different types of tea on depressive symptoms needs to be further explored. This study aimed to examine the association between tea consumption and depressive symptoms in Chinese elderly.Methods: We analyzed the baseline data from Zhejiang Major Public Health Surveillance Program including 9371 participants. Depressive symptoms was assessed through the application of Patient Health Questionnaire-9 scale (PHQ-9). Logistic regression models, controlled for an extensive range of potential confounders, were generated to evaluate the association between tea consumption and risk of depressive symptoms.Results: The black tea drinkers had a significantly decreased risk of depressive symptoms (p<0.01), whereas no association was found in green tea drinkers. Compared with non-drinkers, the adjusted ORs (95% CIs) were 0.48 (0.23, 0.99) and 0.35 (0.17, 0.72) for participants consuming <3 cups and ≥3 cups of black tea per day, respectively (P for trend: <0.01). A linear association between concentration of black tea and depressive symptoms was also confirmed in our study.Limitations: Cross-sectional data could not make a causation conclusion, and the observed association in our study could not be ascribed to any specific component in tea.Conclusions: Our results indicated that higher black tea consumption was associated with a lower prevalence of depressive symptoms in the elderly. [ABSTRACT FROM AUTHOR]

Caffeine has known effects on the central nervous and cardiovascular systems. An intake up to 400 mg/day does not give rise to health concerns. Tea, a major source of caffeine, is highly consumed in China. However, the potential health risk of caffeine from tea has not been well evaluated. The present study assessed caffeine intake levels from tea for Chinese adult consumers. We collected 1,398 samples of green, black, dark, jasmine, oolong, white, and yellow tea from 17 provinces. The caffeine content was determined by HPLC. The average contents were 27 (oolong tea) – 43 (yellow tea) mg/g. The leaching rate of caffeine into the water was about 100%. Tea consumption data were from the National Beverage Consumption Survey 2013–2014. Monte Carlo simulations were applied to estimate the distribution of caffeine intake. The average caffeine intake from tea was 180 mg/day of all consumers. Green, dark, and black tea were the primary sources. Males (197 mg/day) consumed more caffeine than females (136 mg/day) on average, but females older than 71 years had the highest intake level (259 mg/day) among all subgroups. Over 90% of Chinese adult tea drinkers have caffeine intake under 400 mg/day. [Display omitted] • Caffeine intake up to 400 mg/day is safe for healthy adults. • The average caffeine contents in tea were 27 (oolong tea) – 43 (yellow tea) mg/g. • First national risk assessment on caffeine intake from tea for Chinese adults. • Caffeine contents in tea and consumption data was of national representation. • About 10% of Chinese adult tea drinkers consumed more than 400 mg/day of caffeine. [ABSTRACT FROM AUTHOR]

Information on the association between tea drinking and semen quality is limited. Little is reported on whether tea drinking is benefit to sperm quality. This cross-sectional and longitudinal study was conducted between April 2017 and July 2018. Participants were healthy men who were screened as potential sperm donors recruited at the Hubei Province Human Sperm Bank of China. A structured questionnaires containing sociodemographic information, daily habits, sperm collection-related information was completed for each participant at interview. Repeated semen samples were taken to examine the sperm parameters, including sperm volume, sperm concentration, sperm count, progressive motility, and total motility. A total of 1385 men with 6466 sperm samples were included in this study. Two groups were compared: tea drinking men (389, 28.1%) and non-tea drinking men (996, 71.9%). Compared with subjects who never drink tea, the analyses showed that sperm concentration and total sperm count were higher in tea-consuming subjects. A 10-year period or more duration of tea drinking significantly increased semen concentrations by 16.27% (P < 0.05). Sperm concentration was increased in subjects with a frequency of tea drinking of 3 days or more per week (P < 0.05) or, among men who were occasional alcohol drinkers, when tea concentration was weak (P < 0.05). No evidence of trend effects (P for trend > 0.05) or interaction effects (P for interaction > 0.05) between tea consumption and sperm quality, respectively. Our findings provide evidence that tea drinking may improve male reproductive health. Long-term, frequent, weak tea drinking tends to increase sperm quality among men with low BMI or health-related behaviors like smoking or alcohol intake., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Objectives To examine the association between tea consumption and depressive symptoms in Chinese older people and to explore the mediating role of cerebrovascular disease in the association. Design Population-based cross-sectional study. Setting A rural community near Qufu in Shandong, China. Participants Community-dwelling individuals aged 60 and older (mean 68.6; 59.3% female) from the Confucius Hometown Aging Project (N = 1,368). Measurments Data were collected through interviews, clinical examinations, and psychological testing, following a standard procedure. Presence of high depressive symptoms was defined as a score of 5 or greater on the 15-item Geriatric Depression Scale. Results Of the 1,368 participants, 165 (12.1%) were weekly and 489 (35.7%) were daily tea consumers. Compared with no or irregular tea consumption, controlling for age, sex, education, leisure activities, number of comorbidities, and Mini-Mental State Examination score, the odds ratios of having high depressive symptoms were 0.86 (95% confidence interval ( CI) = 0.56-1.32) for weekly and 0.59 (95% CI = 0.43-0.81) for daily tea consumption ( P for linear trend = .001); the linear trend of the association remained statistically significant when further controlling for history of stroke, transient ischemic attacks, and presence of carotid plaques. Conclusions Daily tea consumption is associated with a lower likelihood of depressive symptoms in Chinese older people living in a rural community. The association appears to be independent of cerebrovascular disease and atherosclerosis. [ABSTRACT FROM AUTHOR]

Summary: Objectives: To evaluate the relation of tea consumption with the risk of oral cancer incidence. Subjects and methods: A multicenter case-control study based on hospitalized population was conducted for evaluating the association of tea consumption with oral cancer risk in China. Black tea and green tea were separately analyzed. 723 cases and 857 controls were included. Unconditional multiple logistic regression model was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) of oral cancer for tea consumption. Results: The ORs for green tea consumption⩾8g/day compared with<4g/day were 0.72 (95% CI 0.54, 0.93) for men, and 0.93 (95% CI 0.74, 1.26) for women. The ORs for black tea consumption⩾6g/day compared with<2g/day were 0.97 (95% CI 0.74, 1.20) for men, and 0.91 (95% CI 0.68, 1.23) for women. Green tea intake was significantly associated with reduced risk of oral cancer in men, but not in women, and the association was stronger in heavily smoking men. There was no indication that black tea consumption was associated with decreased oral cancer risk. Conclusion: The results of this study indicated that green tea consumption may decrease the risk of oral cancer in men especially for those smoking heavily. [Copyright &y& Elsevier]

Background: Tea consumption is widely reported to have beneficial effects on metabolic functions. The current study is to evaluate the association between habitual tea consumption and risk for metabolic syndrome and its components among Chinese adults aged 18~59 years., Methods: 43,757 participants aged 18~59 years from China Nutrition and Health Surveillance 2015-2017 were included and divided into four groups based on the amount of daily tea consumption in the current study. Using multiple-adjustment logistic regression to explore the relationship between habitual tea consumption and metabolic syndrome-related health outcomes., Results: Compared with those who did not consume tea habitually, participants who drank over 5 cups of tea per day showed a significantly lower risk of metabolic syndrome (OR = 0.836, 95% CI = 0.771-0.905), blood pressure elevated (OR = 0.906, 95% CI = 0.845-0.972), triglyceride elevated (OR = 0.797, 95% CI = 0.741-0.857), and fasting plasma glucose elevated (OR = 0.772, 95% CI = 0.715-0.833), but higher risk for central obesity (OR = 1.354, 95% CI = 1.236-1.484). Regardless of gender, higher tea consumption was related to lower risk of triglyceride and fasting blood glucose elevated but higher risk for central obesity. While for protective effect on metabolic syndrome, blood pressure elevated, and HDL-C reduction only showed in females., Conclusions: Results from current study support that habitual tea consumption would benefit metabolic syndrome and its related components, especially among females.

Previous studies showed that some components in tea had potential beneficial effects on depression. However, population-based studies examining the potential benefits of tea on depression are limited. We hypothesized that older Chinese with habitual tea consumption had lower levels of depressive symptoms than those without habitual tea consumption. A cross-sectional analysis of baseline data from the Guangzhou Biobank Cohort Study was conducted. Depressive symptoms were measured by the 15-item Geriatric Depression Scale (GDS) score (continuous), with the presence defined by a GDS ≥ 8. Of 10,014 participants, 421 (4.20%) had depressive symptoms. After adjusting for potential confounders, compared with never-consumers, occasional and regular consumers had lower GDS scores (β [95% confidence interval]: -0.29 [-0.46, -0.11] and -0.60 [-0.78, -0.42], respectively), and regular consumers showed lower odds of depressive symptoms (odds ratio [95% CI]: 0.51 (0.35-0.72). In regular tea consumers, greater frequency, amount per occasion and per week, and higher amount-years showed lower GDS score (all P for trend <0.001) and lower odds of depressive symptoms (all P for trend < .05) than nonconsumers. The results were similar by different types of tea (green tea, black tea, and oolong tea) consumed. Further adjustment for social characteristics of tea consumption attenuated the association slightly but not fully. In conclusion, habitual tea consumption was associated with lower levels of depressive symptoms among older Chinese, which might be partly explained by social interaction during consumption. Further investigation on causation and mechanisms, including mechanistic randomized controlled trials is warranted., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Tea consumption may be associated with reduced risk of morbidity and mortality; however, this association is not conclusive and has rarely been investigated among very old adults. The present study examines how self-reported frequency of tea consumption in daily life is associated with health and mortality among very old adults in China. The data are from a national longitudinal data set that included 32 606 individuals (13 429 men and 19 177 women) aged 65 years and older: 11 807 respondents aged 65 to 84 years and 20 799 respondents aged 85 years and older. A total of four measurements between 1998 and 2005 resulted in 51 668 observations. Hazard regressions showed that men who drink tea almost every day have a 10–20 % lower risk of death compared to their counterparts who seldom drink tea, after adjusting for numerous confounders including baseline health. This relationship was stronger in younger male elders aged 65 to 84 years than in the oldest-old men aged 85 years and older. However, frequency of tea consumption was not significantly associated with mortality in women. Our analyses further show that high frequency of tea consumption is significantly associated with reduced OR of disability in activities of daily living, cognitive impairment, self-rated poor health, cumulative health deficits and CVD in both young elders and the oldest-old, and in both men and women. These results suggest that the health benefit of drinking tea is universal. We conclude that frequent tea consumption probably helps one achieve healthy longevity and that men benefit more from such lifestyles. [ABSTRACT FROM PUBLISHER]

• A latent mixture model for systolic blood pressure is used in this study. • Five trajectories of systolic blood pressure are identified in older Chinese adults. • Habitual tea consumption is associated with favorable systolic blood pressure. Tea consumption may contribute to the management of blood pressure; however, evidence from longitudinal studies is lacking. This study aimed to examine the relationship between habitual tea consumption and trajectories of systolic blood pressure in a community-based sample of Chinese adults aged 60 years or older. A prospective cohort of 3870 participants was investigated from 2014 to 2018. Trajectories of systolic blood pressure were identified using latent mixture modeling with the Proc Traj procedure. Multiple logistic regression models were fitted to explore associations between tea consumption habits and trajectories of systolic blood pressure. In the overall sample, participants were less likely to be habitual tea drinkers if they were in the "moderate-stable" (144.4–149.9 mm Hg), "moderate-increasing" (157.2–180.0 mm Hg), and "elevated-increasing" (184.7–209.8 mm Hg) groups as compared to those in the "low-stable" group (125.3–130.0 mm Hg). The "elevated-decreasing" group (170.7 – 167.2 mmHg) consistently showed no significant difference in the likelihood of habitual tea drinking as compared to the "low-stable" group. This community-based prospective study indicated that habitual tea consumption was associated with relatively favorable long-term systolic blood pressure statuses. [ABSTRACT FROM AUTHOR]

A few prospective studies have suggested that tea, alcohol, and fruit consumption may reduce the risk of kidney stones. However, little is known whether such associations and their combined effect persist in Chinese adults, for whom the popular tea and alcohol drinks are different from those investigated in the aforementioned studies. The present study included 502,621 participants from the China Kadoorie Biobank (CKB). Information about tea, alcohol, and fruit consumption was self-reported at baseline. The first documented cases of kidney stones during follow-up were collected through linkage with the national health insurance system. Cox regression was used to calculate the hazard ratio (HR) and 95% confidence interval (CI). During a median of 11.1 years of follow-up, we collected 12,407 cases of kidney stones. After multivariable adjustment, tea, alcohol, and fruit consumption were found to be negatively associated with kidney stone risk, but the linear trend was only found in tea and fruit consumption. Compared with non-tea consumers, the HR (95% CI) for participants who drank ≥7 cups of tea per day was 0.73 (0.65-0.83). Compared with non-alcohol consumers, the HR (95% CI) was 0.79 (0.72-0.87) for participants who drank pure alcohol of 30.0-59.9 g per day but had no further decrease with a higher intake of alcohol. Compared with less-than-weekly consumers, the HR (95% CI) for daily fruit consumers was 0.81 (0.75-0.87). Even for those who did not drink alcohol excessively, increasing tea and fruit consumption could also independently reduce the stone risk. Among Chinese adults, tea, alcohol, and fruit consumption was associated with a lower risk of kidney stones.

Aims: The role of tea consumption in the primary prevention of atherosclerotic cardiovascular disease remains unclear in cohort studies. This prospective cohort study aimed to investigate the associations of tea consumption with the risk of atherosclerotic cardiovascular disease and all-cause mortality., Methods: We included 100,902 general Chinese adults from the project of Prediction for ASCVD Risk in China (China-PAR) in 15 provinces across China since 1998. Information on tea consumption was collected through standardized questionnaires. Outcomes were identified by interviewing study participants or their proxies, and checking hospital records and/or death certificates. Cox proportional hazard regression models were used to calculate hazard ratios and their corresponding 95% confidence intervals related to tea consumption., Results: During a median follow-up of 7.3 years, 3683 atherosclerotic cardiovascular disease events, 1477 atherosclerotic cardiovascular disease deaths, and 5479 all-cause deaths were recorded. Compared with never or non-habitual tea drinkers, the hazard ratio and 95% confidence interval among habitual tea drinkers was 0.80 (0.75-0.87), 0.78 (0.69-0.88), and 0.85 (0.79-0.90) for atherosclerotic cardiovascular disease incidence, atherosclerotic cardiovascular disease mortality, and all-cause mortality, respectively. Habitual tea drinkers had 1.41 years longer of atherosclerotic cardiovascular disease-free years and 1.26 years longer of life expectancy at the index age of 50 years. The observed inverse associations were strengthened among participants who kept the habit during the follow-up period., Conclusion: Tea consumption was associated with reduced risks of atherosclerotic cardiovascular disease and all-cause mortality, especially among those consistent habitual tea drinkers.

Recently, mycotoxins safety in Chinese post-fermented teas has attracted much attention because it is still controversial whether environmental fungi in the teas are able to produce aflatoxins. In this study, a rapid and selective analytical method based on immunoaffinity column (IAC) cleaning coupled with liquid chromatography-mass spectrometry (LC-MS) was developed to quantify four aflatoxins (B 1 , B 2, G 1 and G 2 ) in post-fermented teas. Recoveries ranged from 80.8 to 92.2% with relative standard deviation less than 3%. The limits of detection and quantification were 0.109-0.348 μg kg -1 and 0.364-1.159 μg kg -1 , respectively. Two out of 158 samples were positive for aflatoxins examination (occurrence rate 1.27%). The deterministic assessment for the maximal aflatoxins exposure under upper bound was 9.19 × 10 -6  μg kg -1 day -1 from heavy exposure consumers (≥50 year age group), but the exposure was lower than the JECFA acceptable value of 1.0 ng kg -1 day -1 on liver risk. Probabilistic assessment showed that the upper bound 95th percentile carcinogenic risk value for the 318 consumers (Yunnan China and Ulan Bator Mongolia) was 1.75 × 10 -7 , and for heavy exposure consumers was 2.4 × 10 -7 , and the values equally below the acceptable carcinogenic risk level., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: Previous studies have reported that tea extract supplementation has potential benefits on the risk factors of non-alcoholic fatty liver disease (NAFLD); however, no study has investigated the direct effect of daily tea consumption on the prevalence of NAFLD in the general population. This cross-sectional study aimed to evaluate the associations between tea consumption and the prevalence of newly diagnosed NAFLD among Chinese adults., Methods: The present cross-sectional study was based on the Tianjin Chronic Low-grade Systemic Inflammation and Health Cohort Study. In total, 19,350 participants were enrolled in the analyses. Tea consumption was assessed via a self-administered food frequency questionnaire. NAFLD was diagnosed via liver ultrasonography and no history of heavy alcohol intake. Logistic regression analysis was used to estimate the associations between tea consumption and the prevalence of NAFLD., Results: Consumption of green tea, oolong tea, and black tea were positively associated with the prevalence of newly diagnosed NAFLD before adjustments. Compared with the participants who never drink tea, the odds ratios (95% confidence interval) of newly diagnosed NAFLD in the highest categories (≥ 1 cup/day) of green tea, oolong tea, black tea, and jasmine tea were 1.48 (1.33, 1.65), 1.50 (1.33, 1.68), and 1.28 (1.13, 1.46), and 1.36 (1.20, 1.54) before adjustments, respectively. However, no significant association was found between tea consumption and the prevalence of NAFLD after adjusting for socio-demographic, behavioural, anthropometric, dietary, and clinical confounding factors., Conclusion: There is no significant association between daily tea drinking and newly-diagnosed NAFLD in general Chinese adults.

Current experimental and epidemiological studies provide inconsistent evidence toward the association between tea consumption and cancer incidence. We investigated whether tea consumption was associated with the incidence of all cancers and six leading types of cancer (lung cancer, stomach cancer, colorectal cancer, liver cancer, female breast cancer and cervix uteri cancer) among 455,981 participants aged 30-79 years in the prospective cohort China Kadoorie Biobank. Tea consumption was assessed at baseline (2004-2008) with an interviewer-administered questionnaire. Cancer cases were identified by linkage to the national health insurance system. Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). In the present population, daily tea consumers were more likely to be current smokers and daily alcohol consumers. 22,652 incident cancers occurred during 10.1 years follow-up (5.04 cases/1000 person-years). When we restricted analyses to non-smokers and non-excessive alcohol consumers to minimize confounding, tea consumption was not associated with all cancers (daily consumers who added tea leaves > 4.0 g/day vs. less-than-weekly consumers: HR, 1.03; 95%CI, 0.93-1.13), lung cancer (HR, 1.08; CI, 0.84-1.40), colorectal cancer (HR, 1.08; CI, 0.81-1.45) and liver cancer (HR, 1.08; CI, 0.75-1.55), yet might be associated with increased risk of stomach cancer (HR, 1.46; CI, 1.07-1.99). In both less-than-daily and daily tea consumers, all cancer risk increased with the amount of tobacco smoked or alcohol consumed. Our findings suggest tea consumption may not provide preventive effect against cancer incidence.

Tea is a worldwide drink with controversial effect on bone health. The sex-specific associations are unrevealed among general population. This study showed that prolonged moderate tea consumption benefited bone health in women, while no additional benefit with stronger tea. However, tea consumption was not associated with bone health in men., Introduction: Tea consumption has been shown a potentially beneficial effect on bone health in postmenopausal women. However, little is known about such association in men, and whether stronger tea instead harms bone health due to elevated urinary excretion of calcium associated with caffeine in the tea. The aim of this study was to examine the association between various metrics of tea consumption and bone health., Methods: The present study included 20,643 participants from the China Kadoorie Biobank (CKB), who have finished both baseline survey (2004-2008) and a re-survey (2013-2014). They were aged 38-86 years at re-survey. Tea consumption was self-reported at both baseline and re-survey. Bone mineral density (BMD) was measured using calcaneal quantitative ultrasound once at re-survey., Results: Compared with non-consumers, prolonged weekly tea consumers in women was associated with higher calcaneus BMD measures, with β (95% CI) of 0.98 (0.22, 1.74) for BUA, 4.68 (1.74, 7.61) for SOS, and 1.95 (0.81, 3.10) for SI. Among prolonged weekly tea consumers, no linear increase in BMD measures with the amount of tea leaves added was observed. The SOS and SI were higher in consumers with tea leaves 3.0-5.9 g/day than in those with < 3.0 g/day, but were reduced to non-significant for those with ≥ 6.0 g/day. Tea consumption was not associated with calcaneus BMD measures in men., Conclusion: Prolonged moderate tea consumption benefited bone health in women but not in men. For stronger tea consumption with more tea leaves added, neither benefit nor harm to bone health was observed.

Objective: Whether tea consumption decreases the risk of depression remains controversial. We performed a meta-analysis of findings from observational studies to evaluate the association between tea consumption and depression risk., Method: Embase, PubMed, and Chinese National Knowledge Infrastructure databases were searched from their inception through August 2014 for observational studies that had reported the association between tea consumption and depression risk. We used a fixed effects model when heterogeneity was negligible and a random effect model when heterogeneity was significant to calculate the summary relative risk estimates (RRs) and 95% confidence intervals (CIs)., Results: Eleven studies with 13 reports were eligible for inclusion in the meta-analysis (22,817 participants with 4,743 cases of depression). Compared to individuals with lower tea consumption, those with higher tea consumption had a pooled RR of depression risk at 0.69 (95% CI: 0.63-0.75). Eight reports were included in the dose-response analysis of tea consumption and depression risk (10,600 participants with 2,107 cases). There was a linear association between tea consumption and the risk of depression, with an increment of 3 cups/day in tea consumption associated with a decrease in the risk of depression of 37% (RR = 0.63, 95% CI: 0.55-0.71)., Conclusion: Tea consumption is associated with a decreased risk of depression., (© The Royal Australian and New Zealand College of Psychiatrists 2015.)