Green Tea Intake Research Articles

The advantage of matcha green tea over other drinks: A comprehensive review

Matcha green tea is a finely ground powder made from specially cultivated and processed leaves of Camellia sinensis. Key components of matcha include catechins, caffeine, theanine, fat-soluble vitamins, insoluble dietary fibers, chlorophylls, and proteins. Studies indicate that matcha green tea may offer various health benefits, such as reducing the effects of aging, alleviating stress, and mitigating cognitive impairment. Furthermore, regular consumption of matcha tea supports gut microbiome health, enhances immune function, and reduces the risk of inflammation as well as certain types of cancer. This review strengthens the connection between regular intake of matcha green tea and overall well-being.

Association between dietary tea consumption and non-alcoholic fatty liver disease: a study based on Mendelian randomisation and National Health and Nutrition Examination Survey (2005-2018) association between tea and non-alcoholic fatty liver disease.

Tea can improve the progression of some metabolic diseases through anti-inflammatory and antioxidant effects, but its impact on non-alcoholic fatty liver disease (NAFLD) is still controversial. The aim of this paper is to identify the relationship between tea and NAFLD by Mendelian randomisation (MR) and complete clinical validation using National Health and Nutrition Examination Survey (NHANES) database. MR used data from Genome Wide Association Study, with inverse-variance weighted (IVW) as principal analytical methods. The reliability of the results was verified by a series of sensitivity and heterogeneity tests. Subsequently, clinical validation was conducted using NHANES (2005-2018), involving 22257 participants, grouped by the type of tea. Green tea drinkers were categorised into four groups (Q1-Q4) by quartiles of green tea intake, from lowest to highest (similar for black tea drinkers and other tea drinkers). Models were constructed by logistic regression to estimate the role of tea consumption (Q1-4) on NAFLD. Finally, using fibrosis-4 index (FIB-4) to evaluate the severity of hepatic fibrosis, the effect of tea consumption (Q1-4) on the degree of hepatic fibrosis was investigated by linear regression. IVW method (OR = 0·43, 95 % CI: 0·21, 0·85, P = 0·01) and weighted median method (OR = 0·35, 95 % CI: 0·14, 0·91, P = 0·03) revealed there was a causal relationship between tea and NAFLD. An array of sensitivity analyses validated the reliability of results. Analysis of NHANES indicated tea drinker present a slightly lower prevalence of NAFLD than non-tea drinker (green tea drinkers: 47·6 %, black tea drinkers: 46·3 %, other tea drinker: 43·2 %, non-tea drinkers: 48·1 %, P < 0·05). After adjusting for confounders, compared with the lowest black tea consumption (Q1), the population with the highest black tea consumption (Q4) was independently related to lower presence of NAFLD (Q4: OR = 0·69, 95 % CI: 0·50, 0·93, P < 0·05), such association remained stable in the overweight subgroup. As further analysed, Q4 also displayed a significant negative correlation with the level of hepatic fibrosis in patients with NAFLD (β = -0·073, 95 % CI: -0·126, -0·020, P < 0·01).Tea reduces the morbidity of NAFLD and ameliorates hepatic fibrosis degree in those already suffering from the disease.

Association of Serum Bile Acid Profile with Diet and Physical Activity Habits in Japanese Middle-Aged Men.

Circulating bile acid (BA) profiles change with lifestyle and are closely related to intestinal BA metabolisms such as deconjugation and conversion to secondary BAs. The composition of BA in the blood is involved in systemic nutrient metabolism and intestinal health. Herein, we explored the associations of lifestyle and physical fitness with the circulating BA profile of middle-aged men. Data of 147 male participants (aged 50-64 years; BMI < 26 kg/m2; no medication for diabetes or dyslipidemia) from the Japan Multi-Institutional Collaborative Cohort study were analyzed. Serum concentrations of 15 types of BAs were examined for associations with variables on dietary habits, physical-activity habits, and physical fitness. Green tea intake was positively associated with the deconjugation ratio of total BAs (p = 0.028) and negatively associated with secondary BA levels (free deoxycholic acid [DCA] (p = 0.078), glyco-DCA (p = 0.048), and tauro-DCA (p = 0.037)). In contrast, physical activity was negatively associated with the deconjugation ratio (p = 0.029) and secondary BA levels (free DCA (p = 0.098), and free lithocholic acid (p = 0.009)). Grip strength was also negatively associated with secondary BA levels (tauro-DCA (p = 0.041)) but was not associated with the deconjugation ratio. Energy and fat intake and skeletal muscle mass were not associated with the deconjugation ratio or secondary BA levels. The study findings suggest that lifestyle-associated changes in serum deconjugated and secondary BAs indicate improvements in nutrient metabolism and the intestinal environment.

Exploring causal associations of antioxidants from supplements and diet with attention deficit/hyperactivity disorder in European populations: a Mendelian randomization analysis.

Antioxidants from both supplements and diet have been suggested to potentially reduce oxidative stress in individuals with ADHD. However, there is a lack of studies utilizing the Mendelian randomization (MR) method to explore the relationship between dietary and supplemental antioxidants with ADHD. This study employed two-sample mendelian randomization. Various specific antioxidant dietary supplements (such as coffee, green tea, herbal tea, standard tea, and red wine intake per week), along with diet-derived circulating antioxidants including Vitamin C (ascorbate), Vitamin E (α-tocopherol), Vitamin E (γ-tocopherol), carotene, Vitamin A (retinol), zinc, and selenium (N = 2,603-428,860), were linked to independent single nucleotide polymorphisms (SNPs). Data on ADHD was gathered from six sources, comprising 246,888 participants. The primary analytical method utilized was inverse variance weighting (IVW), with sensitivity analysis conducted to assess the robustness of the main findings. In different diagnostic periods for ADHD, we found that only green tea intake among the antioxidants was significantly associated with a reduced risk of ADHD in males (OR: 0.977, CI: 0.963-0.990, p < 0.001, FDR = 0.065), with no evidence of pleiotropy or heterogeneity observed in the results. Additionally, a nominal causal association was found between green tea intake and childhood ADHD (OR: 0.989, 95% CI: 0.979-0.998, p = 0.023, FDR = 0.843). No causal relationships were detected between the intake of other antioxidant-rich diets and ADHD. Our study found a significant inverse association between green tea intake and male ADHD, suggesting that higher green tea consumption may reduce ADHD risk in males. Further research is needed to explore optimal doses and underlying mechanisms.

Synergistic Effect of β-Cryptoxanthin and Epigallocatechin Gallate on Obesity Reduction.

Chronic obesity is an alarmingly growing global public health concern, posing substantial challenges for the prevention of chronic diseases, including hyperinsulinemia, type 2 diabetes, hyperlipidemia, hypertension, and coronary artery disease, and there is an urgent need for early mitigation strategies. We previously reported the obesity-reducing effects of green tea and β-cryptoxanthin intake. However, since tea has a complex mixture of compounds, it remained unclear which component contributed the most to this effect. Using high-performance liquid chromatography, we analyzed the components of tea in this study to determine if consumption of any combination of these compounds with β-cryptoxanthin had an obesity-reducing effect. Consuming epigallocatechin gallate (EGCG), a component of green tea, and β-cryptoxanthin for 4 weeks led to a decrease in body weight. Moreover, the weight and size of the white adipose tissues were significantly reduced, and blood biochemistry test results were comparable to normal values, with particular improvement in liver function. This indicated that intake of EGCG and β-cryptoxanthin reduces obesity in both subcutaneous and visceral fat. These findings suggest that simultaneous intake of EGCG and β-cryptoxanthin not only reduces obesity but also has a systemic beneficial effect on the body's normal physiological function.

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.

A two-sample Mendelian randomization study of mutual relations of six types of diets in atopic dermatitis.

In the continuous endeavor to find safe and efficient treatments for Atopic Dermatitis (AD), there remains a considerable focus on dietary adjustments. Nevertheless, the limited availability of research and conflicting findings in the academic literature pose a hurdle in establishing conclusive recommendations. Mendelian randomization (MR) was applied to the most comprehensive genome-wide association studies (GWAS) data on tea intake (447485), green tea intake (n=64949), flavored milk intake (n=64941), never eat eggs, dairy, wheat, sugar: Wheat products(n=461046), never eat eggs, dairy, wheat, sugar: Sugar or foods/drinks containing sugar (n=461046), never eat eggs, dairy, wheat, sugar: I eat all of the above (n=461046) and atopic dermatitis (n=218467). We used the inverse-variance weighted method (IVW) as the primary method. The IVW analyses have demonstrated an increased tea intake was genetically associated with a reduced risk of AD (odds ratio [OR]: 0.646, 95% confidence interval [CI]: 0.430-0.968, p=0.034). Furthermore, green tea intake was significantly negatively associated with AD (IVW OR: 0.986, 95% CI: 0.975-0.998; p=0.024) in the IVW model. AD risk could be reduced by never eating wheat products (IVW OR: 8.243E-04, 95% CI: 7.223E-06-9.408E-02, p=0.003). There was no association between never eating eggs, dairy, wheat, sugar: Sugar, or foods/drinks containing sugar, I eat all of the above and AD. Our MR study suggests a causal relationship between tea intake, green tea intake, and the avoidance of eating wheat products with atopic dermatitis. Our findings recommend that preventing and managing atopic dermatitis may be achieved by never eating wheat products while increasing tea and green tea intake.

Higher habitual intakes of flavonoids and flavonoid-rich foods are associated with a lower incidence of type 2 diabetes in the UK Biobank cohort

AimTo examine the associations of a diet high in flavonoid-rich foods, as reflected by a “Flavodiet Score” (FDS), the major individual food contributors to flavonoid intake, and flavonoid subclasses with type 2 diabetes (T2D) risk in the UK Biobank cohort.Materials and methodsFlavonoid intakes were estimated from ≥2 dietary assessments among 113,097 study participants [age at enrolment: 56 ± 8 years; 57% female] using the U.S Department of Agriculture (USDA) databases. Multivariable Cox proportional hazards models were used to investigate associations between dietary exposures and T2D.ResultsDuring 12 years of follow-up, 2628 incident cases of T2D were identified. A higher FDS (compared to lower [Q4 vs. Q1]), characterised by an average of 6 servings of flavonoid-rich foods per day, was associated with a 26% lower T2D risk [HR: 0.74 (95% CI: 0.66–0.84), ptrend = <0.001]. Mediation analyses showed that lower body fatness and basal inflammation, as well as better kidney and liver function partially explain this association. In food-based analyses, higher intakes of black or green tea, berries, and apples were significantly associated with 21%, 15%, and 12% lower T2D risk. Among individual flavonoid subclasses, 19–28% lower risks of T2D were observed among those with the highest, compared to lowest intakes.ConclusionsA higher consumption of flavonoid-rich foods was associated with lower T2D risk, potentially mediated by benefits to obesity/sugar metabolism, inflammation, kidney and liver function. Achievable increases in intakes of specific flavonoid-rich foods have the potential to reduce T2D risk.

The role of green tea intake in thromboprophylaxis of venous thromboembolism in patients with cancer.

Green tea intake has been reported to improve the clinical outcomes of patients with cardiovascular diseases or cancer. It may have a certain role in the development of venous thromboembolism (VTE) among cancer patients. The current study aimed to address this issue, which has been understudied. We carried out a retrospective study to explore the role of green tea intake in cancer patients. Patients with and without green tea intake were enrolled in a 1:1 ratio by using propensity scoring matching. The primary and secondary outcomes were VTE development and mortality 1 year after cancer diagnosis, respectively. The cancer patients with green tea intake (n = 425) had less VTE development (10 [2.4%] vs. 23 [5.4%], p = 0.021), VTE-related death (7 [1.6%] vs. 18 [4.2%], p = 0.026), and fatal pulmonary embolism (PE) (3 [0.7%] vs. 12 [2.8%], p = 0.019), compared with those without green tea intake (n = 425). No intake of green tea was correlated with an increase in VTE development (multivariate hazard ratio (HR) 1.758 [1.476-2.040], p < 0.001) and VTE-related mortality (HR 1.618 [1.242-1.994], p = 0.001), compared with green tea intake. Patients with green tea intake less than 525 mL per day had increased VTE development (area under the curve (AUC) 0.888 [0.829-0.947], p < 0.001; HR1.737 [1.286-2.188], p = 0.001) and VTE-related mortality (AUC 0.887 [0.819-0.954], p < 0.001; HR 1.561 [1.232-1.890], p = 0.016) than those with green tea intake more than 525 mL per day. Green tea intake caused a decrease in platelet (p < 0.001) instead of D-dimer (p = 0.297). The all-cause mortality rates were similar between green tea (39 [9.2%]) and non-green tea (48 [11.3%]) intake groups (p = 0.308), whereas the VTE-related mortality rate in the green tea intake group (7 [1.6%]) was lower than that of the non-green tea intake group (18 [4.2%]) (p = 0.026). The incidences of adverse events were similar between the green tea and non-green tea intake groups. In conclusion, the current study suggests that green tea intake reduces VTE development and VTE-related mortality in cancer patients, most likely through antiplatelet mechanisms. Drinking green tea provides the efficacy of thromboprophylaxis for cancer patients.

Green Tea Intake: A Protective Factor Against Postsurgical Hypothyroidism and Hypoparathyroidism

PurposeTea and coffee are the most common consumed types of drinks, identified with multiple health benefit. However, the association between tea and coffee intake and postsurgical hypothyroidism and hypoparathyroidism (PHypoTP) is still unclear. Therefore, the objective of this study is to explore the effect of tea and coffee intake on the risk of PHypoTP. DesignTwo-sample Mendelian randomization (MR). MethodsThe primary approach for MR estimates was the inverse-variance weighted (IVW) method. MR-Egger, MR Pleiotropy RESidual Sum and Outlier (PRESSO), weighted median, simple mode and weighted mode were used to detect pleiotropy and heterogeneity. FindingsWe found that green tea intake was causally associated with the decreased risk of PHypoTP (β = -0.019; 95% confidence interval [CI]: -0.038 to -0.001; P = 0.029). However, there was no significant association between coffee intake and risk of PHypoTP. No heterogeneity or pleiotropy in these results was detected. ConclusionsOur findings provide the genetic evidence supporting that green tea intake was a protective factor against PHypoTP. Accordingly, we may suggest the patients after thyroidectomy to add green tea into their habitual diet during nursing education.

Tea intake and total body bone mineral density of all ages: a Mendelian randomization analysis.

There is increasing evidence indicating that tea intake affects bone mineral density levels; however, the causality between tea intake and bone mineral density is inconclusive. This study aimed to assess the causal relationship between tea intake and total body bone mineral density (TB-BMD) through two-sample Mendelian randomization (MR) analysis. We conducted a two-sample MR approach to estimate the potential causal effects of tea intake on TB-BMD at all ages in a European population. The analyses were performed using summary statistics obtained for single-nucleotide polymorphisms (SNPs), identified from a genome-wide association meta-analysis of tea intake (N = up to 447,485 individuals) and from the GEnetic Factors for OSteoporosis (GEFOS) Consortium's genome-wide association meta-analysis (N = up to 56,284 individuals), with baseline data collected in 2018 and populations derived from the European ancestry. The association between each SNP and TB-BMD was weighted by its association with tea intake, and estimates were combined mainly using an inverse-variance weighted meta-analysis. In addition, we explored the potential causal effects between green tea intake, herbal tea intake, and TB-BMD. The MR analysis revealed that genetically determined tea intake exerts a causal impact on TB-BMD, with an odds ratio (OR) of 1.204 (95% CI: 1.062-1.366, p = 0.004), especially in the age group of 45-60 years (OR = 1.360, 95% CI: 1.088-1.700, p = 0.007). No horizontal pleiotropy and heterogeneity were observed. However, there was no causal effect of tea intake on TB-BMD in the age groups of 0-15, 15-30, 30-45, and over 60 years. In the subgroup analysis, when green tea intake was regarded as the exposure factor, no salient associations were found between green tea consumption and TB-BMD (IVW p = 0.368). Similarly, there was also no causal association between herbal tea intake and TB-BMD (IVW p = 0.264). The findings of this study support the evidence that tea consumption increases bone density and reduces the risk of osteoporosis in the age group of 45-60 years within the European population.

Investigating the potential causal association between consumption of green tea and risk of lung cancer: a study utilizing Mendelian randomization.

Lung cancer is the most common global cancer in terms of incidence and mortality. Its main driver is tobacco smoking. The identification of modifiable risk factors isa public health priority. Green tea consumption has been examined in epidemiological studies, with inconsistent findings. Thus, we aimed to apply Mendelian randomization to clarify any causal link between green tea consumption and the risk of lung cancer. We utilized a two-sample Mendelian randomization (MR) approach. Genetic variants served as instrumental variables. The goal was to explore a causal link between green tea consumption and different lung cancer types. Green tea consumption data was sourced from the UK Biobank dataset, and the genetic association data for various types of lung cancer were sourced from multiple databases. Our analysis included primary inverse-variance weighted (IVW) analyses and various sensitivity test. No significant associations were found between green tea intake and any lung cancer subtypes, including non-small cell lung cancer (adenocarcinoma and squamous cell carcinoma) and small cell lung cancer. These findings were consistent when applying multiple Mendelian randomization methods. Green tea does not appear to offer protective benefits against lung cancer at a population level. However, lung cancer's complex etiology and green tea's potential health benefitssuggest more research is needed. Further studies should include diverse populations, improved exposure measurements and randomized controlled trials, are warranted.

Association between green tea intake and digestive system cancer risk in European and East Asian populations: a Mendelian randomization study.

Previous observational studies have shown that green tea consumption is associated with a reduced incidence of digestive system cancers (DSCs). However, the observed association could be due to confounding factors. Therefore, we used a two-sample Mendelian randomization (MR) approach to assess the causal effect of green tea intake on the risk of five common DSCs. Independent genetic variants strongly associated with green tea consumption in European and East Asian populations were selected as instrumental variables in genome-wide association studies involving up to 64,949 European individuals and 152,653 East Asian individuals, respectively. The associations between genetic variants and DSCs were extracted from the FinnGen study and the Japan Biobank. The primary analysis was performed using random-effects inverse variance weighting (IVW). Other MR analyses, including weighted mode-based estimate, weighted-median, MR-Egger regression, Mendelian Randomization-Pleiotropy Residual Sum and Outlier (MR-PRESSO) analysis, were used for sensitivity analyses. In addition, a multivariate MR design was performed to adjust for smoking and alcohol consumption. The IVW results showed no causal relationship between tea intake and DSCs risk in European population (esophagus cancer: odds ratio (OR) = 1.044, 95% confidence interval (CI) 0.992-1.099, p = 0.096; stomach cancer: OR = 0.988, 95% CI 0.963-1.014, p = 0.368; colorectal cancer: OR = 1.003, 95% CI 0.992-1.015, p = 0.588; liver cancer: OR = 0.996, 95% CI 0.960-1.032, p = 0.808; pancreatic cancer: OR = 0.990, 95% CI 0.965-1.015, p = 0.432). The MR-Egger regression, MR-PRESSO analysis and other methods also confirmed the reliability of the conclusion. Similarly, no significant association was found between green tea consumption and the incidence of DSCs among East Asians. This relationship is not significant even after adjusting for smoking and alcohol consumption (P > 0.05). Our study provides evidence that genetically predicted green tea intake is not causally associated with the development of DSCs in the European and East Asian population.

First evidence on the causal association between green tea and gastrointestinal health: a two sample mendelian randomization study

ABSTRACT In light of the persisting ambiguity surrounding the causality between green tea intake and gastrointestinal health, this study endeavors to elucidate it using mendelian randomization. Leveraging data from the UK Biobank and FinnGen database, instrumental variants were selected from single-nucleotide-polymorphisms associated with green tea intake. The inverse-variance-weighted method served as the primary analytical approach. Rigorous scrutiny of the results encompassed the Egger intercept test, Mendelian Randomization Presso, Cochran Q test, leave-one-out test, and funnel plot. The primary findings underscore a significant association between green tea intake and gastrointestinal diseases (p = 0.001), indicating heightened consumption of green tea could lead to a reduced risk of gastrointestinal diseases (odds ratio = 0.994). Robustness assessments across all measures substantiate the credibility of these outcomes (all p > 0.05). In conclusion, this study supports the assertion that green tea confers beneficial effects on gastrointestinal health.

Recent advances in dietary androgen receptor inhibitors.

As a nuclear transcription factor, the androgen receptor (AR) plays a crucial role not only in normal male sexual differentiation and growth of the prostate, but also in benign prostatic hyperplasia, prostatitis, and prostate cancer. Multiple population-based epidemiological studies demonstrated that prostate cancer risk was inversely associated with increased dietary intakes of green tea, soy products, tomato, and so forth. Therefore, this review aimed to summarize the structure and function of AR, and further illustrate the structural basis for antagonistic mechanisms of the currently clinically available antiandrogens. Due to the limitations of these antiandrogens, a series of natural AR inhibitors have been identified from edible plants such as fruits and vegetables, as well as folk medicines, health foods, and nutritional supplements. Hence, this review mainly focused on recent experimental, epidemiological, and clinical studies about natural AR inhibitors, particularly the association between dietary intake of natural antiandrogens and reduced risk of prostatic diseases. Since natural products offer multiple advantages over synthetic antiandrogens, this review may provide a comprehensive and updated overview of dietary-derived AR inhibitors, as well as their potential for the nutritional intervention against prostatic disorders.

Phenolic-rich fraction of green tea attenuates histamine-mediated cardiopulmonary toxicity by inhibiting Cox-2/NF-κB signaling pathway and regulating oxidant/antioxidant balance

BackgroundHistamine (HIS) has a substantial impact on the development of numerous allergic disorders including asthma. Antihistamines mostly target histamine receptor-1 alone, so it is not entirely effective in the treatment of allergic diseases. In the current investigation, we examine the growing evidence for novel therapeutic strategies that aim to treat histamine-mediated cardiopulmonary toxicity with the phenolic-rich fraction of green tea (PRFGT).ResultsOur findings demonstrated that weekly ingestion of HIS to rats induced oxidant/antioxidant imbalance in both lung and heart homogenates. The histopathological examination demonstrated extensive interstitial pneumonia with progressive alveolar and bronchial damage in HIS receiving groups. Heart sections showed severe myocardial necrosis and hemorrhage. All lesions were confirmed by the immunohistochemical staining that demonstrated strong caspase-3, cyclooxygenase-2 (Cox-2), and tumor necrosis factor-α (TNF-α) protein expressions along with upregulation of the pulmonary m-RNA expression of TNF-α, nuclear factor kappa-B (NF-κB), and interleukin-1β (IL-1β) genes and cardiac levels of many apoptotic genes. Otherwise, the pretreatment of rats with PRFGT had the ability to alleviate all the aforementioned toxicological parameters and return the microscopic picture of both lung and heart sections to normal histology.ConclusionsWe concluded that PRFGT’s powerful antioxidant, anti-inflammatory, and anti-apoptotic properties can reduce cardiopulmonary toxicity caused by HIS. We recommended daily intake of green tea as a beverage or adding it to foods containing elevated levels of HIS to prevent its possible toxicity.

The effect of antioxidant dietary supplements and diet-derived circulating antioxidants on vitiligo outcome: evidence from genetic association and comprehensive Mendelian randomization.

Previous studies have indicated that antioxidant diets may have a positive impact on vitiligo by interfering with oxidative stress mechanisms. However, there has been a lack of research utilizing the Mendelian randomization (MR) method to analyze the relationship between antioxidant diet intake and vitiligo. In this study, we employed both univariate Mendelian randomization (UVMR) and multivariate Mendelian randomization (MVMR) approaches. The specific antioxidant dietary supplements (such as coffee intake, green tea intake, herbal tea intake, standard tea intake, and average weekly red wine intake) as well as diet-derived circulating antioxidants, including Vit. C (ascorbate), Vit. E (α-tocopherol), Vit. E (γ-tocopherol), Carotene, Vit. A (retinol), Zinc, and Selenium (N = 2,603-428,860) were significantly associated with independent single-nucleotide polymorphisms (SNPs). We obtained pooled statistics on vitiligo from a meta-analysis of three genome-wide association studies (GWASs) of European ancestry, including 4,680 cases and 39,586 controls. Inverse variance weighted (IVW) was employed as the primary analytical method, and sensitivity analysis was conducted to assess the robustness of the main findings. Genetically, coffee intake [odds ratio (OR) = 0.17, 95% confidence interval (CI) 0.07-0.37, p = 1.57 × 10-5], average weekly red wine intake (OR = 0.28, 95% CI 0.08-1.00, p = 0.049), and standard tea intake (OR = 0.99, 95% CI 0.98-0.99, p = 5.66 × 10-7) were identified as protective factors against vitiligo. However, no causal effect between the intake of other antioxidant diets and vitiligo was found. Moreover, no instances of pleiotropy or heterogeneity were observed in this study. Our study indicates that coffee, standard tea, and red wine consumption can potentially reduce the risk of vitiligo. However, there is insufficient evidence to support that other antioxidant diets have a significant effect on vitiligo.

Causal relationship between green tea intake and gastrointestinal disorders: a two-sample Mendelian randomization study.

The precise association between green tea intake and gastrointestinal disorders remains controversial. This study aimed to investigate the potential causal association between green tea intake and gastrointestinal disorders through a two-sample Mendelian randomization (MR) study. Utilizing publicly accessible data from genome-wide association studies (GWAS), we identified SNPs strongly linked with the study variables from multiple large databases to serve as instrumental variables (IVs). MR analyses were executed utilizing the inverse variance weighting (IVW) method, with the resultant effect estimates serving as the primary outcome measure. In addition, a multivariate MR design was performed to adjust for smoking and alcohol consumption. To ensure the robustness of our findings, a series of sensitivity analyses were conducted to assess reliability. Univariable MR analysis revealed suggestive associations between green tea intake and gastroesophageal reflux (OR = 0.9950, 95% CI 0.9900-1.0000, p IVW = 0.047), diverticulosis (OR = 0.9998, 95% CI 0.9996-1.0000, p IVW = 0.030), Crohn's disease (OR = 1.0001, 95% CI 1.0000-1.0002, p IVW = 0.019), and cholangitis was observed (OR = 1.0440, 95% CI 1.0100-1.0790, p IVW = 0.011). Multivariate MR analysis indicated after controlling for potential confounders, greater green tea consumption was suggestively associated with the decreased risk of oesophagitis (OR = 0.9667, 95% CI: 0.9405-0.9936, p IVW = 0.016) and gastric cancer (OR = 0.9810, 95% CI: 0.9628-0.9996, p IVW = 0.046). Nevertheless, multivariate MR analysis also showed that greater green tea consumption was suggestively associated with the increased risk of Crohn's disease (OR = 1.0001, 95% CI: 1.0000-1.0002, p IVW = 0.007). Sensitivity analyses confirmed that these results were reliable. Our study provides suggestive evidence that genetically predicted green tea intake is causally associated with the risk of oesophagitis, gastric cancer and Crohn's disease, but a larger GWAS database is needed for validation.

Stabilization of hypoxia-inducible factor 1α and regulation of specific gut microbes by EGCG contribute to the alleviation of ileal barrier disorder and obesity.

Tea polyphenols have a regulatory effect on metabolic-related diseases, however, the underlying mechanism remains elusive. Our study aims to explore the dietary intervention effect of Epigallocatechin gallate (EGCG), the major polyphenol in green tea, on obesity and intestinal barrier disorders in mice fed a high-fat diet. By supplementing with 50 mg kg-1 EGCG, we observed a significant amelioration in body weight gain, fat accumulation, and liver dysfunction. Furthermore, EGCG modulated the HFD-induced metabolomic alterations. In particular, EGCG intervention restored the ileal barrier by enhancing the expression of tight junction proteins and antimicrobial peptides. At the mechanistic level, EGCG treatment stabilized hypoxia-inducible factor 1α (HIF1α) both in vitro and in vivo. Meanwhile, EGCG significantly increased the abundance of Dubosiella and Akkermansia, along with the elevated SCFA contents. These findings suggest that the ability of EGCG to stabilize HIF1α and regulate specific gut microbes is pivotal in mitigating ileal barrier dysfunction and obesity. Moreover, serum metabolomics revealed potential biomarkers following EGCG intervention. This study supports the intake of EGCG or green tea in obesity management and offers a novel perspective for investigating the metabolic regulatory mechanism of other dietary polyphenols.

젊은 여성과 중년 여성의 차와 음료 소비 비교에 관한 연구

This study compared the differences in tea and beverage intakes of young and middle-aged women. This study investigated the preference and frequency of consumption of beverages and four teas (green tea, black tea, oolong tea, and Pu'er tea), the reasons for consumption and avoidance, and the recognition of the efficacy of green tea and black tea. The young women enjoyed coffee the most, followed by carbonated beverages. The middle-aged women enjoyed coffee the most, but milk and dairy ranked second, resulting in significant differences (p&lt;0.001, p&lt;0.01). In the frequency of beverage intake over the past year, the percentage of carbonated beverages (p&lt;0.001) was significantly higher in young women, while coffee (p&lt;0.001), milk and dairy products (p&lt;0.05), and traditional tea (p&lt;0.001) were significantly higher in the middle-aged women. The young women preferred black tea over green tea, and the middle-aged women preferred Pu’er tea over green tea. The middle-aged women's green tea intake rate was higher than that of the young women (p&lt;0.05). In the young women, ‘taste’ and ‘scent’ were important in both the reasons for tea consumption and avoidance, and the proportion of health-related reasons, such as ‘health care,’ ‘diet,’ and ‘caffeine,’ was high in the middle-aged women (p&lt;0.001). Recognition of the efficacy of green tea was significantly higher in young women than in middle-aged women in the areas of ‘health promotion,’ ‘adult disease prevention,’ ‘weight control,’ and ‘skin beauty.’ In conclusion, the tea intake rate was significantly lower than coffee in both groups. Although the young women group had a higher awareness of the efficacy of green tea than the middle-aged women group, the frequency of green tea consumption was lower, showing a difference due to age. In addition, differences appeared in the reasons for drinking tea and avoiding it between young women who value preference and middle-aged women who value health.