Tea, but not coffee consumption, is associated with components of arterial pressure. The Observation of Cardiovascular Risk Factors study in Luxembourg

A systematic review of tea pigments: Prevention of major diseases, protection of organs, and potential mechanisms and applications

With the growing awareness of a healthy life, tea pigments (TPGs) are in focus for their health benefits. TPGs not only provide specific color to tea liquor but also possess health benefits such as anti-obesity, anti-tumor, anti-inflammatory, anti-viral, anti-oxidative, and bacteriostatic properties. Also, TPGs can benefit bone, liver, kidney, cardiovascular, gut microbiome, and sleep health. Based on previous reports, this review provides a brief introduction to the health benefits of TPGs, focusing on the prevention of human diseases and the protection of organs. Also, the latest research on the functional mechanism(s), practical application, and development strategies of TPGs is discussed.

The association between tea consumption and blood pressure in the adult population in Southwest 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.

Causal relationship between tea intake and cardiovascular diseases: A Mendelian randomization study

Background

Although studies suggest that tea consumption is associated with a reduced risk of cardiovascular disease (CVD). There is no unified conclusion about the potential relationship between tea drinking and CVD. We used a two-sample Mendelian randomized (MR) analysis to systematically explore the causal relationship between tea intake and CVD subtypes for the first time. Furthermore the mediating effect of hypertension was also explored by a two-step MR.

Methods

Genetic instruments for tea intake were identified from a genome-wide association studies (GWAS) involving 447,485 people. Summary data on cardio-vascular disease came from different GWAS meta-analysis studies. In the first step we explored the causal effect of tea intake and CVD. In the second step, we examined the association of hypertension with heart failure and ischemic stroke and estimated the mediating effect of hypertension. Inverse variance weighted MR analysis was used as the primary method for causal analysis. A further sensitivity analysis was performed to ensure robustness of the results.

Results

One standard deviation increase in tea intake was associated with a 25% (OR = 0.75, 95%CI = 0.61–0.91, p = 0.003) lower risk of hypertension, a 28% (OR = 0.72, 95%CI = 0.58–0.89, p = 0.002) lower risk of heart failure, and a 29% (OR = 0.71, 95%CI = 0.55–0.92, p = 0.008) lower risk of ischemic stroke, respectively. And the association between tea drinking and the risk of heart failure and ischemic stroke may be mediated by hypertension. Sensitivity analyses found little evidence of pleiotropy.

Conclusion

Our two-sample MR analysis provided genetic evidence that tea intake was significantly associated with a reduced risk of hypertension, heart failure, and ischemic stroke, and that hypertension may be a potential mediator. Further large randomized controlled trials should be conducted to confirm the causal effect of tea consumption on cardiovascular disease risk.

Associations of tea consumption with blood pressure progression and hypertension incidence

BACKGROUND

Association 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.

METHODS

A 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.

RESULTS

During 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.

CONCLUSIONS

Our study demonstrated that habitual tea consumption could provide preventive effect against blood pressure progression and hypertension incidence.

Associations between habitual tea consumption and 5-year longitudinal changes of systolic blood pressure in older Chinese

BACKGROUND AND OBJECTIVES

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

This community-based prospective study indicated that habitual tea consumption was associated with relatively favorable long-term systolic blood pressure statuses.

The Pharmacological Activity of Camellia sinensis (‎L.‎) ‎Kuntze‎ on Metabolic and Endocrine Disorders: A Systematic Review

Tea made from Camellia sinensis leaves is one of the most consumed beverages worldwide. This systematic review aims to update Camellia sinensis pharmacological activity on metabolic and endocrine disorders. Inclusion criteria were preclinical and clinical studies of tea extracts and isolated compounds on osteoporosis, hypertension, diabetes, metabolic syndrome, hypercholesterolemia, and obesity written in English between 2014 and 2019 and published in Pubmed, Science Direct, and Scopus. From a total of 1384 studies, 80 reports met inclusion criteria. Most papers were published in 2015 (29.3%) and 2017 (20.6%), conducted in China (28.75%), US (12.5%), and South Korea (10%) and carried out with extracts (67.5%, especially green tea) and isolated compounds (41.25%, especially epigallocatechin gallate). Most pharmacological studies were in vitro and in vivo studies focused on diabetes and obesity. Clinical trials, although they have demonstrated promising results, are very limited. Future research should be aimed at providing more clinical evidence on less studied pathologies such as osteoporosis, hypertension, and metabolic syndrome. Given the close relationship among all endocrine disorders, it would be of interest to find a standard dose of tea or their bioactive constituents that would be beneficial for all of them.

Effects and Mechanisms of Tea and Its Bioactive Compounds for the Prevention and Treatment of Cardiovascular Diseases: An Updated Review

Cardiovascular diseases (CVDs) are critical global public health issues with high morbidity and mortality. Epidemiological studies have revealed that regular tea drinking is inversely associated with the risk of CVDs. Additionally, substantial in vitro and in vivo experimental studies have shown that tea and its bioactive compounds are effective in protecting against CVDs. The relevant mechanisms include reducing blood lipid, alleviating ischemia/reperfusion injury, inhibiting oxidative stress, enhancing endothelial function, attenuating inflammation, and protecting cardiomyocyte function. Moreover, some clinical trials also proved the protective role of tea against CVDs. In order to provide a better understanding of the relationship between tea and CVDs, this review summarizes the effects of tea and its bioactive compounds against CVDs and discusses potential mechanisms of action based on evidence from epidemiological, experimental, and clinical studies.

Green Tea Polyphenol Epigallocatechin-3-gallate-Alleviated Coxsackievirus B3-induced Myocarditis Through Inhibiting Viral Replication but Not Through Inhibiting Inflammatory Responses

Viral myocarditis, which is mainly caused by coxsackievirus B3 (CVB3), affects about 5%-20% of the world population and still lacks efficient treatments. Green tea, a tonic and healthful beverage that was originated in ancient China, has been receiving considerable attention for its protective effect on cardiovascular diseases in recent years. In the present investigation, we aimed to explore the effect of green tea polyphenol epigallocatechin-3-gallate (EGCG) on CVB3-induced myocarditis and its underlying mechanism. Our study showed that EGCG could alleviate CVB3-induced myocarditis as evidenced by less cardiac injury and higher survival rate. Furthermore, we found that EGCG failed to downregulate the expression of inflammatory cytokines but could significantly inhibit the replication of CVB3. Furthermore, we found that EGCG treatment could downregulate the protein expression level of coxsackievirus and adenovirus receptor, the major receptor for CVB3 to infect cardiac myocytes. In conclusion, our data indicated that EGCG could ameliorate CVB3-induced myocarditis through inhibiting viral replication, which might provide a potential novel therapeutic strategy for viral myocarditis.

Liver toxicity mechanisms of herbs commonly used in Latin America

Mexico owns approximately 4500 medicinal plants species, a great diversity that position it at the second place after China. According to the Mexican health department, 90% of common population consumes them to treat various diseases. Additionally, herbal remedies in Latin America (LA) are considered a common practice, but the frequency of use and the liver damage related to its consumption is still unknown. Despite the high prevalence and indiscriminate herbal consumption, the exact mechanism of hepatotoxicity and adverse effects is not fully clarified and is still questioned. Some herb products associated with herb induced liver injury (HILI) are characterized by presenting a different chemical composition that may vary from batch to batch, also the biological activity of many medicinal plants and other natural products are directly related to their most active component and its concentration. There are two main biological components that are associated with liver damage, alkaloids, and flavonoids, which are frequent constituents of commonly used herbs. The interaction with the different cytochrome P-450 isoforms, inflammatory, and oxidative activities seem to be the main damage pathway involved in the liver. It is important to know the herbal adverse effects and mechanisms involved; therefore, this article is focused on the beneficial and deleterious effects as well as the possible toxicity mechanisms and interactions of the herbs that are frequently used in LA, since the herb-host interaction may not always be the expected or desired depending on the clinical context in which it is administered.

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

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.

Relationship between dietary caffeine intake and blood pressure in adults

The aim of this study was to determine the consumption frequency of caffeinated foods and beverages and daily caffeine consumption amounts, and examine relation between caffeine and blood pressure (BP). A cross sectional door-to-door interview was conducted with 1329 volunteers between the ages of 20 and 60 (mean ages 29.9 ± 10.8 years) and based in Ankara/Turkey. The rate of individuals whose BPs were above 140/90 mmHg was 13.5%. The median caffeine consumption was 150.0 ± 122.06 mg. Although no significant correlation was found between total caffeine intake and diastolic blood pressure (DBP) of individuals, a positive correlation was observed between daily total caffeine and systolic blood pressure (SBP) (p < .05). Also, when analyzed factors that could be associated with DBP and SBP, BMI had effect in the model formed for both types of BP (p < .05). While smoking status associated with SBP (p = .002), gender and waist circumference related to DBP (p < .05) As a result relationship between caffeine intake and BP was affected other factors.