Association Of Tea Consumption Research Articles

Associations of tea consumption with cognitive function and mental health among older adults in China

Associations of tea consumption with cognitive function and mental health among older adults in China

Tea consumption and risk of incident dementia: A prospective cohort study of 377 592 UK Biobank participants

As a widely consumed beverage, tea boasts diverse health benefits. Herein, we aimed to investigate the association between tea consumption and dementia risk. We conducted a prospective cohort study with 377 592 UK Biobank participants during a 9-year follow-up. Cox regression models adjusted for age, sex, ethnicity, Townsend deprivation index, education, body mass index, lifestyle factors, dietary factors and apolipoprotein E4 status were used to examine the association of tea consumption with dementia risk. Subgroup analyses stratified by age, sex and forms of dementia (Alzheimer’s disease [AD] and vascular dementia [VD]) were performed. Moreover, the restricted cubic splines were used to calculate the nonlinear relationship between daily dosage of tea and dementia risk. After adjustment for all covariates, tea drinkers were 16% (95% confidence interval: 8–23) less likely to develop dementia compared with non-drinkers. Moderate consumption (1–6 cups/day) of tea exerted significant protective effects. Subgroup analyses showed that mid-aged participants or males benefited more from tea consumption. Moreover, moderate drinkers had a 16–19% lower hazard of AD and a 25–29% lower hazard of VD. Furthermore, a U-shaped association between tea consumption and dementia risk was shown (Pnon-linearity = 7E−04), and the consumption of around three cups per day showed the strongest protective effect. Within 3 cups/day, drinking one extra cup of tea per day brought a 6% reduction of incidence. In conclusion, moderate consumption of tea was significantly associated with a reduced risk of dementia, suggesting that tea consumption could be a modifiable lifestyle factor for dementia.

Association between tea consumption and all-cause mortality in Chinese adults

Objective: To investigate the association between tea consumption and the risk of all-cause and cause-specific mortality among Chinese adults. Methods: This study was based on China Kadoorie Biobank (CKB). Tea consumption information was self-reported by participants at baseline. Death was mainly identified by linkage to the death registry system. Cox proportional hazard regression models estimated HR and 95%CI. Results: With a median follow-up of 11.1 years, there were 34 661 deaths in 438 443 participants. Compared with those who never drink tea, all-cause mortality HR(95%CI) were 0.89(0.86-0.91) and 0.92(0.88-0.95) for non-daily tea drinkers and daily tea drinkers, respectively. A statistically significant difference was found in the association of tea consumption and the risk of all-cause mortality between men and women(interaction P<0.05). The protective effect was mainly seen in men. Compared with those who never drink tea, daily tea drinkers had a reduced risk of death from ischemic heart disease, ischemic stroke, hemorrhagic stroke, cancer, respiration diseases and other causes of death, and the corresponding HR(95%CI) were 0.83(0.76-0.92), 0.82(0.69-0.97), 0.86(0.78-0.94), 1.03(0.97-1.09), 1.00(0.87-1.16), 0.84(0.78-0.90). Among never smokers and non-excessive drinkers, there was no statistically significant association between daily tea drinking and the risk of death from cancer. While smokers and excessive drinkers had an increased risk of death from cancer (interaction P<0.001). Conclusions: Tea consumers had reduced risks of all-cause mortality and partial cause-specific mortality, but not for the risk of death from cancer. On the contrary, daily tea drinkers with smoking habits and excessive alcohol drinking had an increased risk of death from cancer.

Associations of tea consumption with blood pressure progression and hypertension incidence.

BACKGROUNDAssociation between tea consumption and incident hypertension remains uncertain. This study conducted to examine the health effects of tea consumption on blood pressure progression and hypertension incidence.METHODSA population-based cohort of 38,913 Chinese participants without hypertension at baseline were included in the current study. Information on tea consumption was collected through standardized questionnaires. Associations of tea consumption with blood pressure progression and incident hypertension were analyzed using logistic regression models and Cox proportional hazards regression models, respectively.RESULTSDuring a median follow-up of 5.9 years, 17,657 individuals had experienced progression to a higher blood pressure stage and 5,935 individuals had developed hypertension. In multivariate analyses, habitual tea drinkers (≥ 3 times/week for at least six months) had a 17% lower risk for blood pressure progression [odds ratio (OR) = 0.83, 95% CI: 0.79–0.88] and a 14% decreased risk for incident hypertension [hazard ratio (HR) = 0.86, 95% CI: 0.80–0.91] compared with non-habitual tea drinkers. Individuals in different baseline blood pressure groups could obtain similar benefit from habitual tea drinking. In terms of tea consumption amount, an inverse, linear dose-response relation between monthly consumption of tea leaves and risk of blood pressure progression was observed, while the risk of incident hypertension did not reduce further after consuming around 100 g of tea leaves per month.CONCLUSIONSOur study demonstrated that habitual tea consumption could provide preventive effect against blood pressure progression and hypertension incidence.

Association of tea consumption and the risk of gastric cancer in Japanese adults: the Japan Collaborative Cohort Study

ObjectiveTo examine the possible relationship between tea consumption and risk of gastric cancer (GC) among Japanese men and women included in a large Japanese population-based study titled the Japan Collaborative...

Tea Consumption Is Associated with Decreased Disease Activity of Rheumatoid Arthritis in a Real-World, Large-Scale Study

Introduction: The role of tea consumption on rheumatoid arthritis (RA) has been studied in recent years, but no clear conclusion has been drawn as a result of small sample size of the studies or the fact that only in vitro studies have been performed. Objectives: The aim of this study was to explore the possible association of tea consumption with RA through a large-scale, real-world study. Methods: A total of 733 RA patients were investigated from June to December, 2016. The disease activity of RA was assessed according to disease activity score 28-erythrocyte sedimentation rate. The amount and types of tea consumption were recorded by on-site self-administered questionnaires. Logistic regression models were applied to analyze the correlation between tea consumption and disease activity, adjusting for demographics, clinical and laboratory factors. Results: There was an inverse association between tea consumption and disease activity in RA patients (OR 0.66, 95% CI 0.46–0.94). Compared with non-tea drinkers, a higher-intake of tea (>750 mL/day) was associated with lower disease activity of RA (OR 0.39, 95% CI 0.19–0.79), but not low-intake (≤750 mL/day; OR 0.83, 95% CI 0.42–1.63). A significant dose-response association was found between the amount of tea consumption and disease activity (p for trend <0.01). Further hierarchical regression analysis showed that such inverse associations were mainly present in female patients (p = 0.004), non-smokers (p = 0.01) or elders (≥60 years; p = 0.01). Conclusion: Tea consumption is associated with decreased disease activity of RA, suggesting the potential beneficial effect of tea in the disease.

Tea consumption is associated with decreased risk of oral cancer: A comprehensive and dose-response meta-analysis based on 14 case-control studies (MOOSE compliant).

The associations of tea consumption with risk of oral cancer remain not clear. The present meta-analysis aims to clarify the real relationship between tea intake and the risk of oral cancer and quantifies the potential dose-response relationship between them.A Web search was performed within Pubmed, Embase, and Web of Science databases to identify potential studies that evaluated the relationship between tea consumption and the risk of oral cancer on Mar 21th, 2018 without language restriction. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were extracted and combined to evaluate the strength of associations. Dose-response analysis was performed to quantitate the relationship between tea intake and risk of oral cancer.Total 14 articles were included in the final analysis. The pooled OR for evaluating the risk of oral cancer and tea intake was 0.700 (95% CI = 0.609–0.805, P <.001). The linearity model of dose-response analysis indicated that with increased 1 cup daily, the risk of oral cancer decreased by 6.2% degree (OR = 0.938, 95% CI = 0.922–0.955, P <.001). Subgroup analysis indicated an inverse association between tea intake and the risk of oral cancer except subgroup analysis of black tea and American people.These results suggest tea intake provides protection against oral cancer carcinogenesis. Additionally, more large-scale pooling and high-quality studies are necessary for detecting the precise relationship between tea intake and oral cancer risk in the future.

Association of Tea Consumption with Risk of Alzheimer's Disease and Anti-Beta-Amyloid Effects of Tea.

Neurodegenerative disease Alzheimer’s disease (AD) is attracting growing concern because of an increasing patient population among the elderly. Tea consumption is considered a natural complementary therapy for neurodegenerative diseases. In this paper, epidemiological studies on the association between tea consumption and the reduced risk of AD are reviewed and the anti-amyloid effects of related bioactivities in tea are summarized. Future challenges regarding the role of tea in preventing AD are also discussed.

Blood Pressure Is Associated with Tea Consumption: A Cross-sectional Study in a Rural, Elderly Population of Jiangsu China.

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). Community-based, cross-sectional study of Suzhou City, Jiangsu Province, China. Tea consumption has protective influence on BP and presence of hypertension. 4579 older adults aged 60 years or older from the Weitang Geriatric Diseases study. 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. 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. 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). 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.

Black tea, green tea and risk of breast cancer: an update

Previous meta-analysis indicated conflicting results in case–control versus cohort studies on the association of green tea with breast cancer risk, and conflicting results were also found in case–control versus cohort studies in another meta-analysis on the association of black tea with breast cancer risk. Many studies were published after the previous meta-analysis. Besides, the dose-response relationship of tea consumption with breast cancer risk is unclear. Thus the association of tea consumption with breast cancer risk was assessed incorporating new publications. Summary relative risk (RR) for highest versus lowest level of tea consumption was calculated based on fixed or random effect models. Dose-response relationship was assessed by restricted cubic spline model and multivariate random-effect meta-regression. The combined results from 9 studies suggested no significant association between green tea consumption and breast cancer risk (RR = 0.82, 95% CI = 0.64-1.04). No significant association was found among cohort studies and case-control studies after sensitivity analysis, respectively. A linear but not significant dose-response association was found between green tea consumption and breast cancer risk. The combined results from 25 studies demonstrated no significant association between black tea consumption and breast cancer risk (RR = 0.98, 95% CI = 0.93-1.03), and no significant association was found in subgroup analysis. A linear but not significant dose-response association was found between black tea consumption and breast cancer risk. Based on the current evidence, black tea and green tea might not contribute significantly to breast cancer risk, respectively.Electronic supplementary materialThe online version of this article (doi:10.1186/2193-1801-2-240) contains supplementary material, which is available to authorized users.

The association of tea consumption with bladder cancer risk: a meta-analysis.

The association between tea consumption and bladder cancer has been confirmed in several animal studies, but one epidemiological study in 2001 showed no association between them. In order to provide an accurate assessment of this, we conducted a meta-analysis on tea consumption and bladder cancer risk. Studies were identified by a literature search in PubMed from January 1980 to March 2012 and the reference lists of relevant studies. Random effect models were used to calculate summary relative risk estimates (RR) and their corresponding 95% confidence intervals (CI) based on high contrast to low intake values. Twenty-four publications (6 cohort studies and 18 case-control studies) based on consumption of overall tea, black tea, and green tea to bladder cancer risk were included in this analysis. For overall tea, the summary RR indicated no association between tea consumption and bladder cancer (RR= 1.09, 95%CI: 0.85-1.40). In subgroup analyses, we found a moderate increase of bladder cancer risk in smoking group (RR= 1.77, 95%CI: 1.04-3.01). In the black tea group, no statistically significant association was observed (RR= 0.84, 95%CI: 0.70-1.01). Interestingly, in the subgroup of sex, a protective effect was observed between tea consumption and bladder cancer risk in female (RR= 0.61, 95%CI: 0.38- 0.98). For green tea group, there was no relationship associated with bladder cancer risk (RR= 1.03, 95%CI: 0.82- 1.31). In conclusion, our data suggest that high overall tea intake in smokers increased the risk of bladder cancer, and high black tea intake in female may reduce the risk of bladder cancer.

Tea consumption and risk of bladder cancer: a meta-analysis

BackgroundTea consumption has been reported to be associated with an decreased risk of several types of cancers. However, the results based on epidemiological studies on the association of tea consumption with bladder cancer were inconsistent. This meta-analysis was undertaken to evaluate the relationship between tea consumption and bladder cancer risk.MethodsEligible studies were retrieved via both computer searches and review of references. The summary relative risk (RR) with 95% confidence interval (CI) was calculated.ResultsTwenty three studies met the inclusion criteria of the meta-analysis. No association with bladder cancer was observed in either overall tea consumption group (OR =0.94, 95% CI 0.85-1.04) or subgroups stratified by sex, study design, geographical region or tea types.ConclusionsOur findings did not support that tea consumption was related to the decreased risk of bladder cancer.

Association of Tea Consumption and Cutaneous Squamous Cell Carcinoma

Laboratory and epidemiologic studies suggest a protective effect of tea consumption on risk of cutaneous squamous cell carcinoma (SCC). We designed a case-control study to examine the association between putative protective exposures, including tea consumption, and SCC risk using a large health maintenance organization population. Cases (n = 415) were defined as Kaiser Permanente Northern California (KPNC) members with a pathology-verified SCC in 2004 and controls (n = 415) were age-, gender-, and race-matched members with no previous history of skin cancer. Tea consumption and SCC risk factors were ascertained by questionnaire. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using conditional logistic regression to estimate the association of SCC with regular use, as well as dose and duration of tea consumption. Risk factor adjusted models included education, smoking, hair and eye color, skin type, family history of skin cancer, and history of freckling, sunburns, sun exposure, and tanning bed use. Adjusted analyses showed no reduction in SCC risk with regular consumption of tea (OR = 1.11, 95% CI: 0.81–1.54). Examining duration, dose, and combined duration and dose exposure variables did not alter findings. We found no evidence that tea consumption was associated with cutaneous SCC risk.

Tea Consumption Is Inversely Associated With Carotid Plaques in Women

The aim of this study was to assess the relationship of tea consumption with common carotid artery intima-media thickness (CCA-IMT) and carotid plaques. The study was performed on 6597 subjects aged > or = 65 years, recruited in the French population for the Three-City Study. Atherosclerotic plaques in the extracranial carotid arteries and CCA-IMT were measured using a standardized protocol. Results were tested for replication in another, younger, French population sample (EVA-Study, 1123 subjects). In the Three-City Study, increasing daily tea consumption was associated with a lower prevalence of carotid plaques in women: 44.0%, 42.5%, and 33.7% in women drinking no tea, 1 to 2 cups/d, and > or = 3 cups/d (P=0.0001). This association was independent of age, center, major vascular risk factors, educational level, and dietary habits (adjOR=0.68[95%CI:0.54 to 0.86] for women drinking > or = 3 cups/d compared with none). There was no association of tea consumption with carotid plaques in men, or CCA-IMT in both genders. In the EVA-Study, carotid plaque frequency was 18.8%, 18.5%, and 8.9% in women drinking no tea, 1 to 2 cups/d, and > or = 3 cups/d (P=0.08). In a large sample of elderly community subjects we showed for the first time that carotid plaques were less frequent with increasing tea consumption in women.

The association of tea consumption with ovarian cancer risk: A metaanalysis

This metaanalysis was undertaken to evaluate the relationship between tea intake and ovarian cancer risk. A systematic literature search up to September 2006 was performed in Medline, Embase, CANCERLIT, and the Cochrane Database. The summary relative risk was calculated. A sensitivity analysis was conducted to test the influence of each single study. Heterogeneity and publication bias were also evaluated. Two cohort and 7 case-control studies were included. The combined relative risk did not show that tea consumption was associated with a reduced ovarian cancer risk (relative risk, 0.84; 95% confidence interval, 0.66-1.07). When the analyses were stratified into subgroups, there was no evidence that study design substantially influenced the estimate of effects. The sensitivity analysis which means removing one study at a time confirmed the stability of our results. Our findings did not support that tea consumption was related to the decreased risk of ovarian cancer.