Black Tea Intake Research Articles

Is There a Relationship Between the Dietary Inflammatory Index and Clinical Attachment Loss in Patients with Periodontitis?

Objective The pathogenesis of periodontal diseases is partially driven by oxidative stress. However, studies on the relationship between periodontitis and the inflammatory load of diet are still insufficient. Therefore, this study aimed to examine the relationship between the diet’s inflammatory load and periodontitis and clinical attachment loss (CAL). Methods This cross-sectional study included 119 participants diagnosed with periodontitis according to the 1999 classification. The dietary inflammatory index (DII) was calculated using three-day food consumption records and divided into quartiles (Q1, Q2, and Q3). Body mass index (BMI) was calculated as weight and height (kg/m2). Clinical attachment loss (CAL) score was determined, and the patients were grouped with those CAL scores as 7 < CAL and ≥7 CAL. Results Of the 119 patients with periodontitis, aged 46.24 ± 12.84 years, 45.3% were found to have an anti-inflammatory diet profile (n = 54). When the daily energy and nutrient intake of individuals were examined, it was found that the intake of omega-3 fatty acids (p = 0.004), black tea (p = 0.021), and green pepper (p = 0.029) was higher in those with CAL < 7 compared to those with CAL ≥ 7. There was no relationship between the patients’ DII and CAL values. Daily energy, protein, fiber, vitamin A, vitamin E, folic acid, Fe, Zn, and Mg intake in patients with an anti-inflammatory diet in Q1 were higher than in Q2 and Q3 (p < 0.001). Conclusion This study found no relationship between DII levels and CAL scores. However, it was observed that periodontitis patients following an anti-inflammatory diet had higher intakes of omega-3 fatty acids, vitamins A, E, and C, as well as zinc and magnesium which are nutrients known to be effective against inflammation. These patients also had CAL scores below 7. Therefore, reducing the inflammatory load of the diet may prevent the development of periodontitis, and further research in this regard would be beneficial.

Tea intake and lung diseases: a Mendelian randomization study.

Existing studies on the relationship between tea intake and lung diseases have yielded inconsistent results, leading to an ongoing dispute on this issue. The impact of tea consumption on the respiratory system remained elucidating. We conducted a two-sample Mendelian randomization (MR) study to evaluate the associations between five distinct tea intake phenotypes and 15 different respiratory outcomes using open Genome-wide association study (GWAS) data. The inverse variance weighted (IVW) was used for preliminary screening and a variety of complementary methods were used as sensitivity analysis to validate the robustness of MR estimates. Pathway enrichment analysis was used to explore possible mechanisms. IVW found evidence for a causal effect of standard tea intake on an increased risk of lung squamous cell cancer (LSCC) (OR = 1.004; 95% CI = 1.001-1.007; P = 0.00299). No heterogeneity or pleiotropy was detected. After adjustment for potential mediators, including smoking, educational attainment, and time spent watching television, the association was still robust in multivariable MR. KEGG and GO enrichment predicted proliferation and activation of B lymphocytes may play a role in this causal relation. No causalities were observed when evaluating the effect of other kinds of tea intake on various pulmonary diseases. Our MR estimates provide causal evidence of the independent effect of standard tea intake (black tea intake) on LSCC, which may be mediated by B lymphocytes. The results implied that the population preferring black tea intake should be wary of a higher risk of LSCC.

In Vitro Model to Evaluate the Development of Discolorations on Human Enamel Caused by Treatment with Mouth Rinses and Black Tea Considering Brushing.

The study aimed to develop and test an in vitro model to investigate the staining potential of mouth rinses on human enamel, considering alternating intake of black tea and tooth brushing, thus mimicking the situation in the oral cavity more realistically. Eight mouth rinses with six different active ingredients (benzydamine hydrochloride [BNZ], polyhexamethylene biguanide hydrochloride [PHMB], chlorhexidine digluconate [CHX], hexetidine gluconate [HEX], octenidine dihydrochloride [OCT] and octenidine dihydrochloride + 2-phenoxyethanol [OCTP]) and concentrations were tested. Sets of six halved human molar crowns were initially pretreated by soaking in artificial saliva (30 min). Afterward, the cyclic treatment was started by soaking in artificial saliva (2 min), staining with black tea (1 min), brushing with toothpaste (5 s), and soaking in the mouth rinse (30 s). Samples were rinsed with distilled water after each treatment step. The cyclic treatment was repeated 30 times, mimicking the consumer behavior after 15 days. Photographic images were taken after 0, 10, 20, and 30 cycles. Color measurements were conducted after each staining and brushing step using a VITA-Easyshade spectrophotometer to determine the difference in lightness ∆L and the total color difference ∆E. Analysis of variance and post-hoc Tukey test (α = 0.05) were applied. The new testing model with included brushing sequences allowed to assess the staining behavior on human teeth and provided a clear differentiation between the different investigated products. In detail, up to cycle 10, ΔE values increased for all mouth rinses with each additional cycle number. However, while ΔE values continued to increase for 0.15% BNZ, 0.1% PHMB, and 0.2% CHX between treatment cycle 10 and 30, ΔE values only slightly increased after treatment with 0.08% OCTP, 0.1% OCTP, 0.1% OCT, and 0.1% HEX. After 20 and 30 cycles, significantly less staining was found for 0.08% OCTP, 0.1% OCT, 0.1% HEX as compared to 0.2% CHX, 0.15% BNZ, and 0.1% PHMB (p < 0.05). ΔE-values were significantly lower after treatment with 0.1% OCTP as compared to 0.2% CHX1 and 0.2% CHX2 (p < 0.05). The proposed new methodology was found to be appropriate for assessing the staining progression of mouth rinses over a simulated application period of 15 days. The model allows differentiation of products with different active ingredients and concentrations.

Tea intake or consumption and the risk of dementia: a meta-analysis of prospective cohort studies.

Dementia affects as many as 130 million people, which presents a significant and growing medical burden globally. This meta-analysis aims to assess whether tea intake, tea consumption can reduce the risk of dementia, Alzheimer's disease (AD) and Vascular dementia (VD). Cochrane Library, PubMed and Embase were searched for cohort studies from inception to November 1, 2022. The Newcastle Ottawa Quality Assessment Scale (NOS) was applied to evaluate the risk of bias of the included studies. We extracted the data as the relative risks (RRs) for the outcome of the interest, and conducted the meta-analysis utilizing the random effect model due to the certain heterogeneity. Sensitivity analysis were performed by moving one study at a time, Subgroup-analysis was carried out according to different ages and dementia types. And the funnel plots based on Egger's and Begger's regression tests were used to evaluate publication bias. All statistical analyses were performed using Stata statistical software version 14.0 and R studio version 4.2.0. Seven prospective cohort studies covering 410,951 individuals, which were published from 2009 and 2022 were included in this meta-analysis. The methodological quality of these studies was relatively with five out of seven being of high quality and the remaining being of moderate. The pooling analysis shows that the relationship between tea intake or consumption is associated with a reduced risk of all-cause dementia (RR = 0.71, 95% CI [0.57-0.88], I2 = 79.0%, p < 0.01). Further, the subgroup-analysis revealed that tea intake or consumption is associated with a reduced risk of AD (RR = 0.88, 95% CI [0.79-0.99], I2 = 52.6%, p = 0.024) and VD (RR = 0.75, 95% CI [0.66-0.85], I = 0.00%, p < 0.001). Lastly, tea intake or consumption could reduce the risk of all-cause dementia to a greater degree among populations with less physical activity, older age, APOE carriers, and smokers. Our meta-analysis demonstrated that tea (green tea or black tea) intake or consumption is associated with a significant reduction in the risk of dementia, AD or VD. These findings provide evidence that tea intake or consumption should be recognized as an independent protective factor against the onset of dementia, AD or VD.

The effect of coffee and black tea consumption on sleep bruxism intensity based on polysomnographic examination

BackgroundSleep bruxism (SB) is a common behavior that can result in various clinical consequences on human health. Risk factors for SB include among others emotional stress, anxiety, tobacco smoking, and excessive alcohol consumption. Coffee and black tea are among the most commonly consumed beverages worldwide. This study explores the influence of coffee and black tea consumption on bruxism intensity, as observed in polysomnographic examination. MethodsPolysomnographic examination with simultaneous camera recording was conducted in 106 adult subjects. The results were evaluated according to guidelines set out by the American Academy of Sleep Medicine (AASM). The study group was divided according to habitual stimulant usage, as declared by the participants in a self-reported questionnaire. Four groups were identified: coffee drinkers versus non-drinkers and black tea drinkers versus non-drinkers. ResultsThe bruxism episode index (BEI) was increased in coffee-drinkers as opposed to non-drinkers (4.59 ± 3.44 vs. 2.87 ± 1.50, p = 0.011). Sleep fragmentation, measured according to the arousal index, was comparable in coffee drinkers and non-drinkers. Electrolyte and lipid levels were similar in coffee drinkers and non-drinkers. Habitual black tea intake did not affect sleep architecture or bruxism intensity. ConclusionsThe study showed that habitual coffee consumption is a risk factor for the increased intensity of sleep bruxism. Neither coffee nor tea consumption is related to sleep fragmentation in habitual drinkers. Coffee and tea intake does not affect electrolyte and lipid concentrations. Caution should therefore be recommended in drinking coffee in people with sleep bruxism.

Relation of Tea Ingestion to Salivary Redox and Flow Rate in Healthy Subjects

The biochemistry of human saliva can be altered by food intake. The benefits of tea drinking were extensively studied but the influence of tea ingestion on human saliva has not been revealed. The work aimed to investigate the immediate and delayed effect of vine tea, oolong tea and black tea intake on certain salivary biochemistry and flow rate. The saliva samples of healthy subjects were collected before, after and 30 min after tea ingestion. The chemical compositions and antioxidant capacity of tea samples were analyzed to correlate with salivary parameters. Principal component analysis indicated that the effects of vine tea consumption were dominated by increasing salivary flow rate (SFR), production rate of total protein (TPC), thiol (SH), malondialdehyde, catalase activity and antioxidant capacity (FRAP) in saliva. The antioxidant profile of studied tea samples (FRAP, polyphenols, flavonoids) was positively correlated with salivary SFR, TPC, SH and FRAP but negatively correlated with salivary uric acid concentration in saliva.

Higher Habitual Dietary Flavonoid Intake Associates With Less Extensive Abdominal Aortic Calcification in a Cohort of Older Women.

The extent of abdominal aortic calcification (AAC) is a major predictor of vascular disease events. We have previously found regular apple intake, a major source of dietary flavonoids, associates with lower AAC. Whether total dietary flavonoid intake impacts AAC remains unknown. Here, we extend our observations to habitual intakes of total flavonoids, flavonoid subclasses, and specific flavonoid-containing foods, with the odds of extensive AAC. We conducted cross-sectional analyses on 881 females (median [interquartile range] age, 80 [78-82] years; body mass index, 27 [24-30] kg/m2) from the PLSAW (Perth Longitudinal Study of Ageing Women). Flavonoid intake was calculated from food-frequency questionnaires. Calcifications of the abdominal aorta were assessed on lateral lumbar spine images and categorized as less extensive or extensive. Logistic regression was used to investigate associations. After adjusting for demographic, lifestyle and dietary confounders, participants with higher (Q4), compared with lower (Q1) intakes, of total flavonoids, flavan-3-ols, and flavonols had 36% (odds ratio [95% CI], 0.64 [0.43-0.95]), 39% (0.61 [0.40-0.93]) and 38% (0.62 [0.42-0.92]) lower odds of extensive AAC, respectively. In food-based analyses, higher black tea intake, the main source of total flavonoids (75.9%), associated with significantly lower odds of extensive AAC (2-6 cups/d had 16%-42% lower odds compared with 0 daily intake). In a subset of nonconsumers of black tea, the association of total flavonoid intake with AAC remained (Q4 versus Q1 odds ratio [95% CI], 0.11 [0.02-0.54]). In older women, greater habitual dietary flavonoid intake associates with less extensive AAC.

Consumption of Food Components of the Mediterranean Diet Decreases the Risk of Breast Cancer in the Makkah Region, Saudi Arabia: A Case-Control Study.

BackgroundBreast cancer is one of the leading causes of death worldwide, it affects both men and women. In Saudi Arabia, breast cancer has been the most prevalent type of cancer in women, for the past few years. Dietary habits and cultural beliefs vary according to region, and further studies are required to demonstrate the relationship between these dietary habits and cultural beliefs and the risk of developing breast cancer. This study is aimed to discover the relationship between preventive dietary factors of the Mediterranean diet and rates of breast cancer among postmenopausal women in the Makkah region of Saudi Arabia.MethodsA case-control study was conducted in King Abdulla Medical City Hospital, Makkah, Saudi Arabia and included 432 Saudi female participants: 218 in the control group and 214 breast cancer patients. All participants were postmenopausal, around the same age, and all were ethnically Arab Saudis. Data were obtained using a self-administered validated questionnaire.ResultsStudy results showed that a diet that includes 1–2 servings of legumes weekly, 1–5 servings of fish weekly, 1–5 servings of dairy products daily, 3–5 servings of fruits and vegetables daily, and more than one cup of black tea and coffee per day significantly (p < 0.05) reduces the risk of breast cancer.ConclusionThis study demonstrates that consuming a Mediterranean diet, which includes legumes, fish, fruits and vegetables, black tea, coffee, and low intake of dairy products, works as a preventive factor against breast cancer in postmenopausal females from the Makkah region.

Renal stone prevalence and risk factors in Jeddah and Riyadh.

ABSTRACTIntroduction:Nephrolithiasis is a common problem worldwide, especially in hot areas like Saudi Arabia. This retrospective study investigated the current prevalence and risk factors of renal stones in Jeddah and Riyadh, Saudi Arabia.Methods:A non-interventional cross-sectional study was conducted from November 2018 to June 2019 at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. This study included 1031 participants (age ≥18 years) from Jeddah (n = 652, 63.30%) and Riyadh (n = 379, 36.80%). Of them, 169 (16.40%) had renal stones while 862 (83.60%) had no renal stones. All participants filled out a questionnaire distributed via social media, which contained questions regarding eating and drinking habits.Results:Significant differences were found between the groups regarding frequencies of intake of black tea and orange/lemon juice. The number of patients who consumed cow meat was significantly higher among those without renal stones than among those with renal stones. Significant high risk for renal stones was found in those who consumed energy drink >1 can/day, black tea >1 cup/day, and orange/lemon juice >1 glass/day.Conclusion:This study revealed that some eating habits play a major role in the development of urinary stones in the Saudi population. Therefore, a dietary intervention on a large scale and health, education in this regard may be helpful in preventing the 25 related to renal stones.

Black Tea Alleviates Particulate Matter-Induced Lung Injury via the Gut-Lung Axis in Mice.

Black tea, as the most consumed kind of tea, is shown to have beneficial effects on human health. However, its impact on particulate matter (PM) induced lung injury and the mechanisms involved have been sparsely addressed. Here, we show that PM-exposed mice exhibited oxidative stress and inflammation in the lungs, which was significantly alleviated by a daily intake of black tea infusion (TI) in a concentration-dependent manner. Interestingly, both the ethanol-soluble fraction (ES) and the ethanol precipitate fraction (EP) exhibited better effects than those of TI; moreover, EP tended to have stronger protection than ES in some indicators, implying that EP played a dominant role in the prevention effects. Furthermore, fecal microbiota transplantation (FMT) revealed that the gut microbiota was differentially reshaped by TI and its fractions were able to directly alleviate the injury induced by PMs. These results indicate that daily intake of black tea and its fractions, especially EP, may alleviate particulate matter-induced lung injury via the gut-lung axis in mice. In addition, the Lachnospiraceae_NK4A136_group could be the core gut microbe contributing to the protection of EP and thus should be further studied in the future.

Effect of Black Tea Consumption on Urinary Risk Factors for Kidney Stone Formation.

Copious fluid intake is the most essential nutritional measure in the treatment of urolithiasis, and is suggested to be a protective factor in the primary prevention of urinary stone formation. Although the intake of black tea contributes to daily fluid intake, the high oxalate content could outweigh the beneficial effect of urine dilution. The present study investigated the effect of black tea consumption on urinary risk factors for kidney stone formation. Ten healthy men received a standardized diet for a period of ten days. Subjects consumed 1.5 L/day of fruit tea (0 mg/day oxalate) during the 5-day control phase, which was replaced by 1.5 L/day of black tea (86 mg/day oxalate) during the 5-day test phase. Fractional and 24-h urines were obtained. The intake of black tea did not significantly alter 24-h urinary oxalate excretion. Urinary citrate, an important inhibitor of calcium stone formation, increased significantly, while the relative supersaturation of calcium oxalate, uric acid, and struvite remained unchanged. No significantly increased risk for kidney stone formation could be derived from the ingestion of black tea in normal subjects. Further research is needed to evaluate the impact of black tea consumption in kidney stone patients with intestinal hyperabsorption of oxalate.

Effect of Black and Green Tea on Salivary pH: a Double Blinded Cross-Over Study

Background: Some herbal products could affect on salivary pH and prevention of dental caries. Tea consumption has inhibition effects on some oral bacteria. Objective: The aim of this study was to evaluate the effect of green and black tea on salivary pH. Material and Methods: In this double blinded cross-over trial, salivary samples of 50 healthy male students of Zahedan Faculty of Dentistry, aged 20-22 years old were collected for evaluation of salivary pH. All volunteers were asked to consume commercially black tea on the first day and then saliva samples were collected before drinking tea and immediately after drinking tea and 5 and 10 minutes after tea consumption. With replacing consumption of green tea, at the second day, saliva samples were collected again. Then the salivary pH was estimated with a digital pH-meter. Data were analyzed through independent t-test and paired samples t-test. Results: Mean salivary pH before and after green tea consumption were 7.15±0.05 and 7.56±0.09, respectively, which showed a remarkable difference (p&lt;0.001). It was 7.14±0.05 and 7.51 ± 0.10, respectively, for black tea, with significant difference (p&lt;0.0001). Mean salivary pH after green tea consumption was significantly higher than black tea (p= 0.006). Conclusion: Both green and black tea intake led to a significant rise in salivary pH, which was higher after green tea consumption compared to black tea. This study suggests the beneficial effects of drinking tea in providing an alkaline environment in oral cavity. KEYWORDS Black tea; Green tea; Saliva; pH.

Comprehensive Understanding of the Relationship between Bioactive Compounds of Black Tea and its Angiotensin Converting Enzyme (ACE) Inhibition and Antioxidant Activity

Long term regular intake of black tea (BT) can lower blood pressure, which is probably due to its antioxidant activity and angiotensin converting enzymes (ACE) inhibitory activity. This study achieves a comprehensive understanding of the relationship between bioactive compounds of BT and its ACE inhibitory activity and antioxidant activity. Phenolic compounds are closely related to antioxidant activity and ACE inhibitory activity. Catechin (C) exhibits stronger inhibitory activity on ACE enzyme than that of other compounds. Molecular docking demonstrates that C could directly bind to ACE active site pockets and Zn(II). Other bioactive compounds are involved in antioxidant and ACE inhibitory activity in varying degrees but no obvious trend is established. Our study proposes a conjecture that some bioactive compounds of BT regulate antioxidant defenses through mechanisms that involve ACE. The mixed mode of in vitro inhibition of ACE and oxidant of BT bioactive compounds needs to be further investigated.

The interindividual variation of salivary flow rate and biochemistry in healthy adults: Influence of black tea consumption

Saliva is firstly interacted with food or drink during ingestion. Alteration of salivary biochemistry by black tea consumption is unclear and rarely discussed in literature. The current work highlighted the immediate and delayed effect of black tea drinking on the change of several salivary parameters, including flow rate, α-amylase and catalase activity, malondialdehyde, thiol, nitric oxide, hydrogen peroxide and total protein content. Twelve healthy subjects aged between 22 and 31 years old were recruited in the study. The saliva was collected before, after and 30 min after black tea consumption. The black tea intake generally caused an increase of salivary flow rate, total protein content, catalase, H2O2 and MDA but reduction in thiol and nitric oxide for majority of the subjects. Principal component analysis showed that the salivary flow rate, production rate of total protein content, nitric oxide, thiol and malondialdehyde of saliva were primarily significant for black tea consumption.

Tea Flavonoids and Risk of Cardiovascular and All-Cause Mortality: A Systematic Review and Meta-Analysis

AbstractThere is increasing evidence that both black and green tea are beneficial for prevention of cardiovascular disease (CVD). We conducted a systematic review and meta-analysis evaluating the effects of tea flavonoids on cardiovascular (CVD) and all-cause mortality outcomes.Searches across five databases including PubMed and Embase were conducted through November 2018 to identify randomized controlled trials (RCTs) and prospective cohort studies reporting cardiovascular and all-cause mortality outcomes. Two investigators independently conducted abstract and full-text screenings, data extractions, and risk of bias (ROB) assessments using the Nutrition Evidence Library Bias Assessment Tool (NEL BAT). Mixed-effects dose-response meta-regression and standard random-effects meta-analyses for outcomes with ≥ 4 studies were performed. 0 RCTs and 38 prospective cohort studies were included in the systematic review. NEL BAT scores ranged from 0–15 (0 being the lowest risk). Our linear meta-regression model showed that each cup increase in daily tea consumption (about 280 mg and 338 mg of total flavonoids for black and green tea, respectively) was associated with 3–4% lower risk of CVD mortality (predicted adjusted RR = 0.96; CI 0.93–0.99 for green tea and RR = 0.97; CI 0.94–0.99 for black tea). Furthermore, eachcup increase in daily tea consumption was associated a 2% lower risk of all-cause mortality (predicted adjusted relative risk (RR) = 0.98; 95% CI 0.97–0.99 for black tea and RR = 0.98; CI 0.96–0.99 for green tea, respectively). Two studies reported multivariable Cox regression analysis results for the relationship between black tea intake and risks of all-cause mortality outcomes. The results from these two studies were combined with our linear meta-regression result in a random-effects model meta-analysis and showed that each cup increase in daily black tea consumption was associated with an average of 3% lower risk of all-cause mortality (pooled adjusted RR = 0.97; 95% CI 0.87- 1.00) with large heterogeneity (I2 = 81.4%; p = 0.005). Current evidence indicates that increased tea consumption may reduce cardiovascular and all-cause mortality in a dose-response manner. This systematic review was registered on PROSPERO.

Associations between tea and coffee beverage consumption and the risk of lung cancer in the Singaporean Chinese population.

Tea and coffee are widely consumed beverages. Tea flavonoids have been shown to inhibit lung tumorigenesis using in vitro and in vivo models. Conversely, coffee contains complex mixtures of biochemically active compounds, some of which may have genotoxic and mutagenic properties. However, previous epidemiologic studies have shown inconsistent results on tea and coffee in relation to lung cancer risk. The Singapore Chinese Health Study is a population-based prospective cohort of 63,257 Singaporean Chinese men and women, with an average of 17.7years of follow-up. Information on tea and coffee consumption and other lifestyle factors was collected through in-person interviews at baseline. Multivariable Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations with adjustment for potential confounders. There were 1486 incident lung cancer cases. Compared to non-daily coffee drinkers, HRs (95% CIs) of lung cancer riskfor those consuming one, two, and three or more cups of coffee per day were 1.18 (1.02-1.36), 1.21 (1.05-1.40), and 1.32 (1.08-1.62) respectively (P for trend = 0.0034). The highest category of black tea consumption (at least 2 cups per day) was inversely associated with risk of lung cancer [HR (95% CI) = 0.73 (0.53-0.99)], particularly among men [HR (95% CI) = 0.67 (0.47-0.95)], compared to less-than-weekly black tea drinkers, although the interaction by sex was not statistically significant. Coffee beverage consumption was associated with higher risk of developing lung cancer. On the other hand, black tea intake was associated with lower risk of lung cancer among men in our cohort, and further studies are needed to confirm this association.

성인여성의 홍차섭취와 체질량지수 및 우울 정도와의 관련성

성인여성의 홍차섭취와 체질량지수 및 우울 정도와의 관련성

In vivo Effects of Black and Green Tea on Serum Lipid Profile and Cardiac Function in Hyperlipidemic Rats

Objective: The study was designed to investigate the in vivo effects of black and green tea consumption on serum lipid profile and cardiac function in hyperlipidemic rats. Methods: 24 male Wistar rats, average weight 125 g were sorted into four groups: A, B, C and D. Normal control group (A) were fed standard rat chow; the remaining three groups (B, C and D) received rat chow supplemented with 2% (w/w) cholesterol to induce hypercholesterolemia. Group C and D were administered 40 mg/ml of black and green tea respectively while group B (hyperlipidemic control) were not treated. The feeding and tea administration lasted 6 weeks. Results: Significant reduction in body weight and heart weight index was recorded in rats administered black and green tea compared with the untreated group. Black and green tea consumption also caused significant decrease in total cholesterol, LDL-cholesterol, triglycerides and coronary heart disease (CHD) risk ratio accompanied with elevated HDL-cholesterol compared to untreated group. Significant alterations in cardiac marker enzymes: creatine kinase (CK), gamma glutamyl transferase (GGT) and lactate dehydrogenase (LDH) were also observed in serum and heart homogenates of untreated hyperlipidemic rats which were normalized in rats administered the teas. These results are synonymous with decreased risk of atherosclerosis and protective potential on cardiac function by green and black tea. Conclusion: We conclude in this study that regular intake of black and green tea might be useful in treatment of obesity and prevention of cardiovascular complications arising from hyperlipidemia.

Tea Flavonoids and Risk of Cardiovascular and All-Cause Mortality: A Systematic Review and Meta-Analysis (P06-126-19)

ObjectivesTo conduct a systematic review and meta-analysis evaluating the effects of tea flavonoids on cardiovascular (CVD) and all-cause mortality outcomes. MethodsSearches across five databases including PubMed and Embase were conducted through November 2018 to identify randomized controlled trials (RCTs) and prospective cohort studies reporting cardiovascular and all-cause mortality outcomes. Two investigators independently conducted abstract and full-text screenings, data extractions, and risk of bias (ROB) assessments using the Nutrition Evidence Library Bias Assessment Tool (NEL BAT). Mixed-effects dose-response meta-regression and standard random-effects meta-analyses for outcomes with ≥4 studies were performed. Results0 RCTs and 38 prospective cohort studies were included in the systematic review. NEL BAT scores ranged from 0–15 (0 being the lowest risk). Our linear meta-regression model showed that each cup increase in daily tea consumption (about 280 mg and 338 mg of total flavonoids for black and green tea, respectively) was associated with 3–4% lower risk of CVD mortality (predicted adjusted RR = 0.96; CI 0.93–0.99 for green tea and RR = 0.97; CI 0.94–0.99 for black tea). Furthermore, each cup increase in daily tea consumption was associated a 2% lower risk of all-cause mortality (predicted adjusted relative risk (RR) = 0.98; 95% CI 0.97–0.99 for black tea and RR = 0.98; CI 0.96–0.99 for green tea, respectively). Two studies reported multivariable Cox regression analysis results for the relationship between black tea intake and risks of all-cause mortality outcomes. The results from these two studies were combined with our linear meta-regression result in a random-effects model meta-analysis and showed that each cup increase in daily black tea consumption was associated with an average of 3% lower risk of all-cause mortality (pooled adjusted RR = 0.97; 95% CI 0.87–1.00) with large heterogeneity (I2 = 81.4%; p = 0.005). ConclusionsCurrent evidence indicates that increased tea consumption may reduce CVD and all-cause mortality in a dose-response manner. This systematic review was registered on PROSPERO. Funding SourcesFunding for this study was provided through an unrestricted educational grant from Unilever. The funding body had no influence on the study design; the collection, analysis, and interpretation of data; the writing of the report; and the decision to submit the paper for publication.

Comparative effect of black, green, oolong, and white tea intake on weight gain and bile acid metabolism.

The beneficial effects of tea on health, including obesity, are well known. However, the comparative effects of black, green, white, and oolong teas, which are prepared from the same fresh leaves, on weight gain and the potential mechanisms involved are not yet fully understood. Bile acids (BAs) are shown to be powerful regulators of metabolism; however, to our knowledge, no studies have investigated the effect of tea on BA metabolism. The aim of this study was to investigate the modulatory effects that green, black, white, and oolong teas that were prepared from the same raw tea leaves have on the plasma BA profile. Female rats were dosed with the aforementioned tea types as their sole source of drinking fluid for 28 d. We then investigated their weight and effect on BA metabolic profile using advanced ultra-performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS)-based metabolomics. The UPLC-MS/MS analysis of the plasma show that the levels of murocholic acid, glycochenodeoxycholic acid, glycocholic acid, glycodeoxycholic acid, taurochenodeoxycholic acid, tauroursodeoxycholic acid, taurodeoxycholic acid, tauromuricholic acid, and taurocholic acid were increased; whereas levels of taurolithocholic acid and isolithocholic acid were decreased after drinking green, oolong, and white tea types compared with control. Surprisingly, oolong tea significantly influenced reduction in relative weight compared with control, black, and green tea; whereas black, green, and white teas had no effects on weight compared with control. Green, black, oolong, and white teas altered the BA metabolism. This change in BA metabolism could be associated with the health benefit effects of tea. Oolong tea was most effective in reducing weight.