Low-dose green tea intake reduces incidence of atrial fibrillation in a Chinese population

Unraveling tea and coffee consumption effects on cardiovascular diseases risk factors: A narrative review

Backgrounds and Aims

Daily lifestyle plays a vital role in modifying the risk for cardiovascular diseases (CVDs). Our daily life isn't inseparable from nutrition intake. As such, tea and coffee are often regarded as the most consumed beverages worldwide. There have been a lot of debates on the adverse effects and benefits of consuming these popular beverages. This comprehensive review explores the different types of tea and coffee and their mechanism of action. It delves deeper into their roles in reducing CVD risk, aiding CVD recovery, lowering CVD mortality, and their varying effects across populations and regions.

Methods

An extensive literature search was conducted on PubMed. Relevant articles were identified through cross-referencing and manual searches. Excluded from the study were commentaries, case reports, clinical vignettes, and non-English articles.

Results

Tea and coffee contain varying levels of caffeine and other bioactive compounds with cardioprotective effects against oxidative stress, inflammation, and more. Genetic factors further modulate their effects. Tea flavonoids benefit cholesterol, blood pressure, and endothelial function, while coffee constituents impact oxidative stress, metabolism, insulin sensitivity, and gut flora. Moderate consumption of both beverages may offer cardiovascular benefits, but outcomes vary depending on populations and conditions. Tea and coffee consumption may influence CVD recovery by reducing mortality and improving survival, however, it must be noted that it has the potential to be harmful to some individuals.

Conclusion

Evidence suggests that moderate consumption of these beverages may be linked to reduced cardiovascular mortality, although individual characteristics and pre-existing conditions can influence outcomes. Excessive caffeine consumption, found in both beverages, may pose risks such as arrhythmias, hypertension, and cardiovascular mortality in CVD patients, with a dose-dependent nature. Future research should delve into mechanisms, genetic factors, and diverse cultural impacts of its use. Health care providers should consider individual characteristics when advising on tea and coffee consumption in the context of cardiovascular health.

Evaluating the effect of green tea intake on cardiovascular diseases: A Mendelian randomization study in European and East Asian populations

Previous research shows that more than 70% of cardiovascular diseases (CVDs) are attributed to modifiable risk factors. Here, we investigated relationship between consumption of green tea in European and East Asian populations and risk of CVDs using Mendelian randomization (MR). Instrumental variables for green tea intake were obtained from genome-wide association studies (GWASs) of 64,949 Europeans and 152,653 East Asians. GWASs for CVDs were derived from UK BioBank and BioBank Japan projects. The main method selected for MR analysis was either the inverse variance weighted (IVW) or Wald ratio, depending on the quantity of single nucleotide polymorphisms. Furthermore, we performed sensitivity analyses to confirm the reliability of the findings. Based on the results of IVW, there is no causal relationship between consumption of green tea and risk of 4 CVDs among Europeans (atrial fibrillation: OR = 1.000, 95% CI: 0.995-1.005, P = .910; heart failure: OR = 1.003, 95% CI: 0.994-1.012, P = .542; ischemic stroke: OR = 1.002, 95% CI: 0.993-1.011, P = .690; coronary artery disease: OR = 1.001, 95% CI: 0.996-1.007, P = .677). Sensitivity analyses and supplementary MR analyses also verify the robustness of the findings. Likewise, there was no correlation between the consumption of green tea and the occurrence of CVDs in East Asians. The consumption of green tea is not associated with a reduced risk of CVDs in populations from Europe and East Asia. This means that those who are trying to reduce their risk of CVDs by drinking more green tea may not benefit from doing so.

Atrial fibrillation: primary prevention, secondary prevention, and prevention of thromboembolic complications: part 1

Atrial fibrillation (AF), is the most common sustained cardiac arrhythmia. It was once thought to be benign as long as the ventricular rate was controlled, however, AF is associated with significant cardiac morbidity and mortality. Increasing life expectancy driven by improved health care and decreased fertility rates has, in most of the world, resulted in the population aged ≥65 years growing more rapidly than the overall population. As the population ages, projections suggest that the burden of AF may increase more than 60% by 2050. Although considerable progress has been made in the treatment and management of AF, primary prevention, secondary prevention, and prevention of thromboembolic complications remain a work in progress. This narrative review was facilitated by a MEDLINE search to identify peer-reviewed clinical trials, randomized controlled trials, meta-analyses, and other clinically relevant studies. The search was limited to English-language reports published between 1950 and 2021. Atrial fibrillation was searched via the terms primary prevention, hyperthyroidism, Wolff-Parkinson-White syndrome, catheter ablation, surgical ablation, hybrid ablation, stroke prevention, anticoagulation, left atrial occlusion and atrial excision. Google and Google scholar as well as bibliographies of identified articles were reviewed for additional references. In these two manuscripts, we discuss the current strategies available to prevent AF, then compare noninvasive and invasive treatment strategies to diminish AF recurrence. In addition, we examine the pharmacological, percutaneous device and surgical approaches to prevent stroke as well as other types of thromboembolic events.

Free Radicals and Obesity-Related Chronic Inflammation Contrasted by Antioxidants: A New Perspective in Coronary Artery Disease

We are surrounded by factors called free radicals (FR), which attach to the molecules our body is made of, first among them the endothelium. Even though FR are to a certain extent a normal factor, nowadays we face an escalating increase in these biologically aggressive molecules. The escalating formation of FR is linked to the increased usage of man-made chemicals for personal care (toothpaste, shampoo, bubble bath, etc.), domestic laundry and dish-washer detergents, and also an ever wider usage of drugs (both prescription and over the counter), especially if they are to be used long-term (years). In addition, tobacco smoking, processed foods, pesticides, various chronic infectious microbes, nutritional deficiencies, lack of sun exposure, and, finally, with a markedly increasing impact, electromagnetic pollution (a terribly destructive factor), can increase the risk of cancer, as well as endothelial dysfunction, owing to the increased production of FR that they cause. All these factors create endothelial damage, but the organism may be able to repair such damage thanks to the intervention of the immune system supported by antioxidants. However, one other factor can perpetuate the state of inflammation, namely obesity and metabolic syndrome with associated hyperinsulinemia. In this review, the role of FR, with a special emphasis on their origin, and of antioxidants, is explored from the perspective of their role in causing atherosclerosis, in particular at the coronary level.

No causal association between tea consumption and 7 cardiovascular disorders: A two-sample Mendelian randomization study

Background: Previous studies have reported inconsistent results on the causal association between habitual tea consumption and the risk of cardiovascular disease (CVD). This study is aim to determine the association between habitual tea intake and CVD using two-sample Mendelian randomization (MR) analysis. Methods: The genetically predicted causation between tea consumption and 7 common cardiovascular diseases (atrial fibrillation, hypertension, acute myocardial infarction, coronary atherosclerosis, peripheral vascular disease, angina, and heart failure) was evaluated using MR analysis model. We performed a total of 9 MR analysis methods to analyze the final results. The IVW methods was used as the primary outcome. The other MR analysis method (simple mode, weighted mode, simple median, weighted median, penalized weighted median, MR Egger, and MR-Egger (bootstrap)) were performed as the complement to IVW. Also, the robustness of the MR analysis results was assessed using a leave-one-out analysis. Results: The IVW analysis methods indicated that there is no causal association between tea consumption and risk of CVD (AF: OR, 0.997, 95% CI, 0.992-1.0001, p = 0.142; hypertension: OR, 0.976, 95% CI, 0.937-1.017, p = 0.242; AMI: OR, 0.996, 95% CI, 0.991-1.000, p = 0.077; CA: OR, 1.001, 95% CI, 0.993-1.009, p = 0.854; PVD: OR, 1.002, 95% CI, 1.000-1.005, p = 0.096; angina: OR, 0.999, 95% CI, 0.993-1.006, p = 0.818; HF: OR, 0.999, 95% CI, 0.996-1.002, p = 0.338). The other MR analysis method and further leave-one-out sensitivity analysis suggested the results were robust. Conclusion: This MR study indicated that there was no genetically predicted causal association between habitual tea intake and risk of CVD.

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.

No causal effect of tea consumption on cardiovascular diseases: A two-sample Mendelian randomization study

Background

Numerous studies have been conducted to investigate the relationship between tea consumption and the risk of cardiovascular diseases (CVD); however, no conclusive results have been achieved. We conducted a Mendelian randomization (MR) study to elucidate the causal associations between tea consumption and several CVD outcomes, including coronary artery disease (CAD), myocardial infarction (MI), atrial fibrillation (AF), and heart failure (HF).

Methods

Independent single-nucleotide polymorphisms (SNPs) genome-wide significantly associated with tea consumption were used as instrumental variables (IVs). Summary statistics for CVD outcomes were obtained from the corresponding genetic consortia and the FinnGen consortium. The inverse-variance weighted (IVW) method was the primary analytical method, and MR estimates from different data sources were combined using fixed-effects meta-analysis. Supplementary MR analyses, including the weighted median, MR-Egger, and the MR pleiotropy residual sum and outlier methods, were conducted to evaluate the robustness of the results. Further MR analyses were repeated by including more genetic variants at a higher P-value threshold.

Results

We found that genetically predicted tea consumption was not causally associated with any CVD outcomes in the IVW method using data from large genetic consortia [CAD: odds ratio (OR) = 1.00, 95% confidence interval (CI), 0.91, 1.10, P = 0.997; MI: OR = 0.98, 95% CI, 0.90, 1.08, P = 0.751; AF: OR = 0.97, 95% CI, 0.92, 1.03, P = 0.350; HF: OR = 0.96, 95% CI, 0.88, 1.05, P = 0.401] or the FinnGen consortium (CAD: OR = 1.06, 95% CI, 0.96, 1.17, P = 0.225; MI: OR = 1.01, 95% CI, 0.89, 1.15, P = 0.882; AF: OR = 1.00, 95% CI, 0.88, 1.14, P = 0.994; HF: OR = 0.96, 95% CI, 0.88, 1.04, P = 0.362). The results were robust and consistent across meta-analysis, supplementary MR analyses, and analyses with more IVs included.

Conclusion

This MR study revealed no causal association between tea consumption and four CVD outcomes, suggesting that tea consumption may not be beneficial for the primary prevention of CVD.

Therapeutic Feasibility of the Natural Products in the Heart Complaints: An Overview

Heart pain is the most frequent complaint leading patients to seek medical help. Functional heart symptoms, especially chest pain, are prevalent and, according to the International Classification of Diseases (ICD-10), are described as "somatoform autonomous functional disorders of the cardiovascular system." The problem lies in the fact that pain does not always have a somatic background, that is, it may be related to crucial underlying heart disease. The population does not know how to differentiate somatic pain from significant ischemic symptoms, and based on the patient's complaints, traditional medicine ends up treating other underlying cardiac diseases. Many unsuccessful unconventional therapies have been proposed in recent years, including herbal medicines that seek to disrupt the disease's pathogenesis. The present review summarizes research carried out in the last 5 years on natural products' heart complaints, including myocardial ischemia, arrhythmia, and heart failure. Several herbal medicines may be used as a replacement or complementary treatment strategy. A total of 17 medicinal plants have shown promising results in preclinical studies. However, human clinical trials are scarce; only two have been presented. Generally, the data are bland, and many issues have been raised about herbal therapies' safety, efficacy, and mode of action. Besides, relevant clinical trials, future perspectives, and possible clinical applications are discussed.

Coffee and tea on cardiovascular disease (CVD) prevention

Coffee and tea are amongst the most consumed beverages worldwide, and are the main source of caffeine in adults. In this review we present findings on the effects of habitual coffee and tea consumption on cardiovascular disease (CVD) prevention. Mild-moderate coffee/ caffeine consumption, at 2-3 cups/day, is associated with beneficial effects on metabolic syndrome, including hypertension and diabetes mellitus, although may elevate lipid levels. Furthermore, coffee consumption reduces the risk of coronary heart disease, heart failure, arrhythmia, stroke, CVD and all cause mortality. Higher tea consumption, in particular green tea, confers similar cardiovascular benefits to coffee with 3 cups/day associated with improved survival in population based studies.

A review on plants and herbal components with antiarrhythmic activities and their interaction with current cardiac drugs

This paper aimed to compile information on plants or their compounds which have experimentally shown antiarrhythmic effect and to scrutinize the efficacy and potency of them and their potential interaction with conventional cardiac drugs. Literature searches were accomplished by using numerous electronic databases, and the available knowledge on different parts of herbs and their ingredients with antiarrhythmic effects up to 2019 were identified and collected. The results indicate that 36 herbs or their derivatives can be effective in the treatment of arrhythmias, especially in animal and cellular models. They affect various ionic channels in different action potential phases. The alterations in ionic currents lead to changing in the amplitude and duration of the action potential, effective refractory period, maximum velocity, resting membrane potential, channel trafficking, or intracellular calcium concentration. The agents that prolong action potential duration and effective refractory period such as dauricine and sophocarpine seem to be more beneficial if more comprehensive studies confirm their efficacy and safety. It is noteworthy that the consumption of some herbal agents for cardiovascular (e.g. Hawthorn and Ginseng) or other (e.g. Ginseng and Licorice) therapeutic purposes may boost the pro-arrhythmogenic effect of current cardiovascular drugs such as cardiac glycosides. This study accentuates known plants or their derivatives with anti-arrhythmic effects, potential interaction with other cardiac drugs, and the possible mechanisms involved. It can assist clinicians and scientists in research and therapeutic approaches to the management of cardiac arrhythmias.