Instruct: Given a question, retrieve relevant passages that answer the question.
Query: Better Than Green Tea?
OBJECTIVE: Hyperglycemia, oxidative stress, and the onset and progression of diabetic complications are strongly linked. Reduction of oxidative stress could be of utmost importance in the long-term treatment of diabetic patients. The chronic nature of the disease calls for a mode of antioxidant intake that can be sustained easily, e.g., by the diet. Erythritol, a simple polyol, could be such a compound. It is orally available, well tolerated, and its chemical structure resembles that of mannitol, a well-known hydroxyl radical (HO*) scavenger. METHODS: We studied the antioxidant properties of erythritol in vitro and subsequently determined its antioxidant activity and its vasoprotective effect in the streptozotocin diabetic rat. RESULTS: Erythritol was shown to be an excellent HO* radical scavenger and an inhibitor of 2,2'-azobis-2-amidinopropane dihydrochloride-induced hemolysis but inert toward superoxide radicals. High-performance liquid chromatographic and electron spin resonance spectroscopy studies showed that the reaction of erythritol with hydroxyl radicals resulted in the formation of erythrose and erythrulose by abstraction of a carbon-bound hydrogen atom. In the streptozotocin diabetic rat, erythritol displayed an endothelium-protective effect and, in accordance with the in vitro experiments, erythrose was found in the urine of erythritol-consuming rats. CONCLUSION: Erythritol acts as an antioxidant in vivo and may help protect against hyperglycemia-induced vascular damage. Copyright 2010 Elsevier Inc. All rights reserved.
INTRODUCTION: Kombucha "mushroom'' tea is touted to have medicinal properties. Here, we present a case of hyperthermia, lactic acidosis, and acute renal failure within 15 hours of Kombucha tea ingestion. CASE PRESENTATION: A 22 year old male, newly diagnosed with HIV, became short of breath and febrile to 103.0F, within twelve hours of Kombucha tea ingestion. He subsequently became combative and confused, requiring sedation and intubation for airway control. Laboratories revealed a lactate of 12.9 mmol/L, and serum creatinine of 2.1 mg/dL. DISCUSSION: Kombucha tea is black tea fermented in a yeast-bacteria medium. Several case reports exist of serious, and sometimes fatal, hepatic dysfunction and lactic acidosis within close proximity to ingestion. CONCLUSION: While Kombucha tea is considered a healthy elixir, the limited evidence currently available raises considerable concern that it may pose serious health risks. Consumption of this tea should be discouraged, as it may be associated with life-threatening lactic acidosis.
The identification of modifiable lifestyle factors that could reduce the risk of breast cancer is a research priority. Despite the enormous chemo preventive potential of green tea and compelling evidence from animal studies, its role in breast cancer development in humans is still unclear. Part of the uncertainty is related to the relatively small number of epidemiological studies on green tea and breast cancer and that the overall results from case-control studies and prospective cohort studies are discordant. In addition, the mechanisms by which green tea intake may influence risk of breast cancer in humans remains not well studied. We review the human studies that have evaluated the relationship between green tea intake and four biomarkers (sex steroid hormones, mammographic density, insulin-like growth factor, adiponectin) that are believed to be important in breast cancer development. Results from these biomarker studies are also inconclusive. Limitations of human studies and areas of further investigations are discussed.
OBJECTIVE: To evaluate the hypolipemic and antioxidant effects of soy and green tea alone and/or in association in dyslipidemic subjects. METHODS: One hundred dyslipidemic individuals were allocated into four groups. The soy group ingested 50 g of soy (kinako) daily, and the green tea group ingested 3 g of green tea in 500 mL of water per day. A third group ingested 50 g of soy and 3 g of green tea daily, and the control group had a hypocholesterolemic diet. Evaluations were performed at baseline and after 45 and 90 d. Plasma levels of total cholesterol, high-density lipoprotein, and triacylglycerols were evaluated by automated methods. Low-density lipoprotein (LDL) cholesterol was calculated using the Friedewald equation. LDL was isolated by ultracentrifugation. Total plasma antioxidant capacity and plasma levels of total lipid hydroperoxides and those linked to LDL were evaluated by chemiluminescence. The results were expressed as median values and their 25th to 75th percentiles, with a 5% level of significance. RESULTS: No significant difference occurred in LDL, high-density lipoprotein cholesterol, and triacylglycerol levels across groups. However, a statistically significant difference in total cholesterol occurred within the soy/green tea group 45 and 90 d after intervention. No statistically significant difference occurred in plasma levels of lipid hydroperoxides or those linked to LDL in any of the groups studied. All the groups that used soy and/or green tea presented increased total plasma antioxidant potential. CONCLUSION: Soy and green tea, alone or in combination, increased the total antioxidant potential of hypercholesterolemic patients, whereas only the combination decreased total cholesterol levels.
OBJECTIVE: To investigate the efficacy and cost effectiveness of an herbal tea, Smooth Move, in nursing home residents with chronic constipation. DESIGN: Double-blind, placebo-controlled, 2-armed, parallel-group clinical trial. SETTING: A 483-bed nursing home in Allentown, Pennsylvania, operated by Lehigh County Government. PARTICIPANTS: A total of 86 nursing home residents with chronic constipation. INTERVENTIONS: Participants (n = 86) were randomly assigned to receive Smooth Move (n = 42) or a placebo (n = 44), once daily, in addition to standard treatment for chronic constipation. The study period was 28 days. MEASUREMENTS: The primary efficacy parameter was the difference in total number of bowel movements. Secondary parameters included the difference in average number of standard treatment doses dispensed, and the difference in total medication costs. RESULTS: Compared to placebo, in the intention to treat (ITT analysis) there was a statistically significant increase in the number of bowel movements in the Smooth Move group. The Smooth Move group (n = 42) compared with the placebo group (n = 44) experienced an average of 4.14 more bowel movements during the 28-day study period versus the 28-day pre-study period (P = .017). CONCLUSION: Smooth Move herbal tea, when added to the standard treatment regimen for nursing home residents with chronic constipation, increased the average number of bowel movements compared to the addition of a placebo tea.
To compare the antihypertensive effectiveness of sour tea (ST; Hibiscus sabdariffa) with black tea (BT) infusion in diabetic patients, this double-blind randomized controlled trial was carried out. Sixty diabetic patients with mild hypertension, without taking antihypertensive or antihyperlipidaemic medicines, were recruited in the study. The patients were randomly allocated to the ST and BT groups and instructed to drink ST and BT infusions two times a day for 1 month. Their blood pressure (BP) was measured on days 0, 15 and 30 of the study. The mean of systolic BP (SBP) in the ST group decreased from 134.4+/-11.8 mm Hg at the beginning of the study to 112.7+/-5.7 mm Hg after 1 month (P-value <0.001), whereas this measure changed from 118.6+/-14.9 to 127.3+/-8.7 mm Hg (P-value=0.002) in the BT group during the same period. The intervention had no statistically significant effect on the mean of diastolic BP (DBP) in either the ST or BT group. The mean pulse pressure (PP) of the patients in the ST group decreased from 52.2+/-12.2 to 34.5+/-9.3 mm Hg (P-value <0.001) during the study, whereas in the BT group, it increased from 41.9+/-11.7 to 47.3+/-9.6 mm Hg (P-value=0.01). In conclusion, consuming ST infusion had positive effects on BP in type II diabetic patients with mild hypertension. This study supports the results of similar studies in which antihypertensive effects have been shown for ST.
There is a belief that caffeinated drinks, such as tea, may adversely affect hydration. This was investigated in a randomised controlled trial. Healthy resting males (n 21) were recruited from the general population. Following 24 h of abstention from caffeine, alcohol and vigorous physical activity, including a 10 h overnight fast, all men underwent four separate test days in a counter-balanced order with a 5 d washout in between. The test beverages, provided at regular intervals, were 4 × 240 ml black (i.e. regular) tea and 6 × 240 ml black tea, providing 168 or 252 mg of caffeine. The controls were identical amounts of boiled water. The tea was prepared in a standardised way from tea bags and included 20 ml of semi-skimmed milk. All food taken during the 12 h intervention period was controlled, and subjects remained at rest. No other beverages were offered. Blood was sampled at 0, 1, 2, 4, 8 and 12 h, and a 24 h urine sample was collected. Outcome variables were whole blood cell count, Na, K, bicarbonate, total protein, urea, creatinine and osmolality for blood; and total volume, colour, Na, K, creatinine and osmolality for urine. Although data for all twenty-one participants were included in the analysis (mean age 36 years and mean BMI 25·8 kg/m(2)), nineteen men completed all conditions. Statistical analysis, using a factorial ANOVA approach within PROC MIXED, revealed no significant differences between tea and water for any of the mean blood or urine measurements. It was concluded that black tea, in the amounts studied, offered similar hydrating properties to water.
BACKGROUND: The aim of this study was to evaluate and compare the effectiveness of 0.5% tea, 2% neem, and 0.2% chlorhexidine mouthwashes on oral health. MATERIALS AND METHODS: A randomized blinded controlled trial with 30 healthy human volunteers of age group 18-25 years was carried out. The subjects were randomly assigned to 3 groups i.e., group A - 0.2% chlorhexidine gluconate (bench mark control), Group B - 2% neem, and group C - 0.5% tea of 10 subjects per group. Plaque accumulation and gingival condition were recorded using plaque index and gingival index. Oral hygiene was assessed by simplified oral hygiene index (OHIS). Salivary pH was assessed by indikrom pH strips. Plaque, gingival, and simplified OHI scores as well as salivary pH were recorded at baseline, immediately after 1 st rinse, after 1 week, 2 nd week, and 3 rd week. The 3 rd week was skipped for group A. RESULTS: Mean plaque and gingival scores were reduced over the 3 week trial period for experimental and control groups. Anti-plaque effectiveness was observed in all groups and the highest being in group C (P < 0.05). Neem and tea showed comparative effectiveness on gingiva better than chlorhexidine (P < 0.05). The salivary pH rise was sustained and significant in Group B and C compared to Group A. Oral hygiene improvement was better appreciated in Group B and Group C. CONCLUSION: The effectiveness of 0.5% tea was more compared to 2% neem and 0.2% chlorhexidine mouth rinse.
Despite its antioxidant capacity and well-known health benefits, yerba mate tea (Ilex paraguariensis) has been shown to possess some genotoxic and mutagenic activities and to increase incidence of some types of cancer. The aim of this study was to estimate the cyto- and genotoxicity of mate tea in human peripheral lymphocytes in vitro. We found that yerba mate extract induced a concentration-dependent, statistically significant increase in the level of apoptotic and necrotic cells and a decrease in the nuclear division index (NDI). Mate-exposed lymphocytes had a reduced transcriptional rDNA activity, which may be due to the stress conditions, and showed an elevated production of micronuclei. The FISH technique revealed the appearance of an acrocentric signal in mate-induced micronuclei, which suggests that under these conditions yerba mate extract may display aneugenic activity. Since caffeine is one of the most abundant compounds found in the dry mass of mate, we conducted additional experiments with caffeine alone. We showed that caffeine used at the same concentrations manifests a more potent cyto- and genotoxic effect that may account, at least in part, for the disadvantageous effects observed for yerba mate extract.
OBJECTIVES: There is increasing evidence that intake of sour tea (Hibiscus sabdariffa) has hypoglycemic and hypolipidemic effects and may benefit patients suffering from metabolic disorders such as diabetes. The objective of the present study was to investigate the hypolipidemic effects of sour tea in patients with diabetes and compare them with those of black tea. DESIGN: In this sequential randomized controlled clinical trial, 60 patients with diabetes were recruited and randomly assigned into two groups: sour tea (ST) and black tea (BT). They were instructed to consume sour tea or black tea two times a day for 1 month. OUTCOME MEASURES: Fasting blood samples were taken at the beginning and at the end of the study for evaluation of lipids, lipoproteins, and apoproteins. RESULTS: Fifty-three (53) patients concluded the study. In the ST group, mean of high-density lipoprotein-cholesterol (HDLc) increased significantly (p = 0.002) at the end of the study, whereas changes in apolipoprotein-A1, and lipoprotein (a) were not significant. Also, a significant decrease in the mean of total cholesterol, low density lipoprotein-cholesterol, triglycerides, and Apo-B100 were seen in this group. In the BT group, only HDLc showed significant change (p = 0.002) at the end of the study and changes in the other measures were not statistically significant. CONCLUSIONS: The results of the present study showed that ST has a significant effect on blood lipid profile in patients with diabetes.
BACKGROUND: Epidemiological studies suggest that tea consumption decreases cardiovascular risk, but the mechanisms of benefit remain undefined. Endothelial dysfunction has been associated with coronary artery disease and increased oxidative stress. Some antioxidants have been shown to reverse endothelial dysfunction, and tea contains antioxidant flavonoids. Methods and Results-- To test the hypothesis that tea consumption will reverse endothelial dysfunction, we randomized 66 patients with proven coronary artery disease to consume black tea and water in a crossover design. Short-term effects were examined 2 hours after consumption of 450 mL tea or water. Long-term effects were examined after consumption of 900 mL tea or water daily for 4 weeks. Vasomotor function of the brachial artery was examined at baseline and after each intervention with vascular ultrasound. Fifty patients completed the protocol and had technically suitable ultrasound measurements. Both short- and long-term tea consumption improved endothelium- dependent flow-mediated dilation of the brachial artery, whereas consumption of water had no effect (P<0.001 by repeated-measures ANOVA). Tea consumption had no effect on endothelium-independent nitroglycerin-induced dilation. An equivalent oral dose of caffeine (200 mg) had no short-term effect on flow-mediated dilation. Plasma flavonoids increased after short- and long-term tea consumption. CONCLUSIONS: Short- and long-term black tea consumption reverses endothelial vasomotor dysfunction in patients with coronary artery disease. This finding may partly explain the association between tea intake and decreased cardiovascular disease events.
Evidence supports a trial period of eliminating colourings and preservatives from the diet
Tea is the most widely consumed beverage in the world after water. Tea is known to be a rich source of flavonoid antioxidants. However tea also contains a unique amino acid, L-theanine that may modulate aspects of brain function in humans. Evidence from human electroencephalograph (EEG) studies show that it has a direct effect on the brain (Juneja et al. Trends in Food Science & Tech 1999;10;199-204). L-theanine significantly increases activity in the alpha frequency band which indicates that it relaxes the mind without inducing drowsiness. However, this effect has only been established at higher doses than that typically found in a cup of black tea (approximately 20mg). The aim of the current research was to establish this effect at more realistic dietary levels. EEG was measured in healthy, young participants at baseline and 45, 60, 75, 90 and 105 minutes after ingestion of 50mg L-theanine (n=16) or placebo (n=19). Participants were resting with their eyes closed during EEG recording. There was a greater increase in alpha activity across time in the L-theanine condition (relative to placebo (p+0.05). A second study replicated this effect in participants engaged in passive activity. These data indicate that L-theanine, at realistic dietary levels, has a significant effect on the general state of mental alertness or arousal. Furthermore, alpha activity is known to play an important role in critical aspects of attention, and further research is therefore focussed on understanding the effect of L-theanine on attentional processes.
To investigate effects of dietary mushrooms and joint effects of mushrooms and green tea on breast cancer, a case-control study was conducted in southeast China in 2004-2005. The incident cases were 1,009 female patients aged 20-87 years with histologically confirmed breast cancer. The 1,009 age-matched controls were healthy women randomly recruited from outpatient breast clinics. Information on frequency and quantity of dietary intake of mushrooms and tea consumption, usual diet, and lifestyle were collected by face-to-face interview using a validated and reliable questionnaire. Compared with nonconsumers, the Odds ratios (Ors) were 0.36 (95% CI = 0.25-0.51) and 0.53 (0.38-0.73) for daily intake of >or=10 g fresh mushrooms and >or=4 g dried mushrooms, based on multivariate logistic regression analysis adjusting for established and potential confounders. There were dose-response relationships with significant tests for trend (p < 0.001). The inverse association was found in both pre- and postmenopausal women. Compared with those who consumed neither mushrooms nor green tea, the ORs were 0.11 (0.06-0.20) and 0.18 (0.11-0.29) for daily high intake of fresh and dried mushrooms combined with consuming beverages made from >or=1.05 g dried green tea leaves per day. The corresponding linear trends were statistically significant for joint effect (p < 0.001). We conclude that higher dietary intake of mushrooms decreased breast cancer risk in pre- and postmenopausal Chinese women and an additional decreased risk of breast cancer from joint effect of mushrooms and green tea was observed. More research is warranted to examine the effects of dietary mushrooms and mechanism of joint effects of phytochemicals on breast cancer.
Among the many known health benefits of tea catechins count anti-inflammatory and neuroprotective activities, as well as effects on the regulation of food intake. Here we address cannabimimetic bioactivity of catechin derivatives occurring in tea leaves as a possible cellular effector of these functionalities. Competitive radioligand binding assays using recombinant human cannabinoid receptors expressed in Chem-1 and CHO cells identified (-)-epigallocatechin-3-O-gallate, EGCG (K(i)=33.6 microM), (-)-epigallocatechin, EGC (K(i)=35.7 microM), and (-)-epicatechin-3-O-gallate, ECG (K(i)=47.3 microM) as ligands with moderate affinity for type 1 cannabinoid receptors, CB1. Binding to CB2 was weaker with inhibition constants exceeding 50 microM for EGC and ECG. The epimers (+)-catechin and (-)-epicatechin exhibited negligible affinities for both CB1 and CB2. It can be concluded that central nervous cannabinoid receptors may be targeted by selected tea catechins but signaling via peripheral type receptors is less likely to play a major role in vivo.
Background Tea consumption is associated with a lower risk of cardiovascular disease including stroke. Direct effects of tea components on the vasculature, particularly the endothelium, may partly explain this association. Objective We performed a meta-analysis of controlled human intervention studies on the effect of tea on flow-mediated dilation (FMD) of the brachial artery, a measurement of endothelial function, which is suggested to be associated with cardiovascular risk. Methods Human intervention studies were identified by systematic search of the databases Medline, Embase, Chemical s and Biosis through March 2009 and by hand-searching related articles. Studies were selected based on predefined criteria: intervention with tea as the sole experimental variable, placebo-controlled design, and no missing data on FMD outcome or its variability. A random effects model was used to calculate the pooled overall effect on FMD due to the intake of tea. The impact of various subject and treatment characteristics was investigated in the presence of heterogeneity. Results In total, 9 studies from different research groups were included with 15 relevant study arms. The overall absolute increase in FMD of tea vs. placebo was 2.6% of the arterial diameter (95% CI: 1.8-3.3%; P-value <0.001) for a median daily dose of 500 mL of tea (2–3 cups). This is a relative increase of approximately 40% compared to the average FMD of 6.3% measured under placebo or baseline conditions. There was significant heterogeneity between studies (P-value <0.001) that might partly be explained by the cuff position either distal or proximal to the area of FMD measurement. No indication for publication bias was found. Conclusion Moderate consumption of tea substantially enhances endothelial-dependent vasodilation. This may provide a mechanistic explanation for the reduced risk of cardiovascular events and stroke observed among tea drinkers.
BACKGROUND: The present analysis was conducted in response to inconsistent epidemiologic studies on the relation between consumption of tea and cardiovascular diseases. OBJECTIVE: We undertook a literature review of the consistency and strength of the associations between tea and cardiovascular diseases on the basis of published observational studies and meta-analyses addressing tea or tea flavonoids and cardiovascular disease risk. DESIGN: We performed a search in 3 databases for meta-analyses and compared them with studies they subsumed. We performed an additional search for subsequent studies to determine whether the conclusions were consistent. RESULTS: Many epidemiologic studies have been conducted and summarized in 5 meta-analyses on either tea consumption or flavonoid consumption and cardiovascular disease or the subset of stroke. Heterogeneity of effect was seen when the outcome included all cardiovascular diseases. In the case of stroke, a consistent, dose-response association with tea consumption on both incidence and mortality was noted with RRs of 0.80 (95% CI: 0.65, 0.98) for flavonoids and 0.79 (95% CI: 0.73, 0.85) for tea when high and low intakes were compared or the addition of 3 cups/d was estimated. CONCLUSION: Thus, the strength of this evidence supports the hypothesis that tea consumption might lower the risk of stroke.
Mentha spicata Labiatae, known as spearmint and Mentha piperita Labiatae, known as peppermint can be used for various kinds of illnesses in herbal medicine and flavoring in industry. M. spicata Labiatae grows on the Anamas plateau of Yenithornarbademli town of Isparta, located in southwest part of Turkey. In this town, clinicians thought that consumption of tea steeped with M. spicata or M. piperita caused a diminished libido. Because antiandrogenic effects of spearmint and peppermint were found previously in rats, it was decided to observe the effect of this herbal tea on the androgen levels in hirsute women.Twenty-one female hirsute patients, 12 with polycystic ovary syndrome and 9 with idiopathic hirsutism were included to the study. They were took a cup of herbal tea which was steeped with M. spicata for 5 days twice a day in the follicular phase of their menstrual cycles. After treatment with spearmint teas, there was a significant decrease in free testosterone and increase in luteinizing hormone, follicle-stimulating hormone and estradiol. There were no significant decreases in total testosterone or dehydroepiandrostenedione sulphate levels. Spearmint can be an alternative to antiandrogenic treatment for mild hirsutism. Further studies are needed to test the reliability of these results and the availability of spearmint as a drug for hirsutism. Copyright 2007 John Wiley & Sons, Ltd.
Bile acid binding capacity has been related to the cholesterol-lowering potential of foods and food fractions. Lowered recirculation of bile acids results in utilization of cholesterol to synthesize bile acid and reduced fat absorption. Secondary bile acids have been associated with increased risk of cancer. Bile acid binding potential has been related to lowering the risk of heart disease and that of cancer. Previously, we have reported bile acid binding by several uncooked vegetables. However, most vegetables are consumed after cooking. How cooking would influence in vitro bile acid binding of various vegetables was investigated using a mixture of bile acids secreted in human bile under physiological conditions. Eight replicate incubations were conducted for each treatment simulating gastric and intestinal digestion, which included a substrate only, a bile acid mixture only, and 6 with substrate and bile acid mixture. Cholestyramine (a cholesterol-lowering, bile acid binding drug) was the positive control treatment and cellulose was the negative control. Relative to cholestyramine, in vitro bile acid binding on dry matter basis was for the collard greens, kale, and mustard greens, 13%; broccoli, 10%; Brussels sprouts and spinach, 8%; green bell pepper, 7%; and cabbage, 5%. These results point to the significantly different (P < or = .05) health-promoting potential of collard greens = kale = mustard greens > broccoli > Brussels sprouts = spinach = green bell pepper > cabbage as indicated by their bile acid binding on dry matter basis. Steam cooking significantly improved the in vitro bile acid binding of collard greens, kale, mustard greens, broccoli, green bell pepper, and cabbage compared with previously observed bile acid binding values for these vegetables raw (uncooked). Inclusion of steam-cooked collard greens, kale, mustard greens, broccoli, green bell pepper, and cabbage in our daily diet as health-promoting vegetables should be emphasized. These green/leafy vegetables, when consumed regularly after steam cooking, would lower the risk of cardiovascular disease and cancer, advance human nutrition research, and improve public health.
There are over 750 species of bacteria that inhabit the human oral cavity, but only a small fraction of those are attributed to causing plaque-related diseases such as caries. Streptococcus mutans is accepted as the main cariogenic agent and there is substantial knowledge regarding the specific virulence factors that render the organism a pathogen. There has been rising interest in alternative, target-specific treatment options as opposed to nonspecific mechanical plaque removal or application of broad-spectrum antibacterials that are currently in use. The impact of diet on oral health is undeniable, and this is directly observable in populations that consume high quantities of polyphenol-rich foods or beverages. Such populations have low caries incidence and better overall oral health. Camellia sinensis, the plant from which various forms of tea are derived, and Vaccinium macrocarpon (American cranberry fruit) have received notable attention both for their prevalence in the human diet as well as for their unique composition of polyphenols. The biologically active constituents of these plants have demonstrated potent enzyme-inhibitory properties without being bactericidal, a key quality that is important in developing therapies that will not cause microorganisms to develop resistance. The aim of this review is to consider studies that have investigated the feasibility of tea, cranberry, and other select plant derivatives as a potential basis for alternative therapeutic agents against Streptococcus mutans and to evaluate their current and future clinical relevance.
In vitro studies show Hibiscus sabdariffa L., an ingredient found in many herbal tea blends and other beverages, has antioxidant properties, and, in animal models, extracts of its calyces have demonstrated hypocholesterolemic and antihypertensive properties. Our objective in this study was to examine the antihypertensive effects of H. sabdariffa tisane (hibiscus tea) consumption in humans. A randomized, double-blind, placebo-controlled clinical trial was conducted in 65 pre- and mildly hypertensive adults, age 30-70 y, not taking blood pressure (BP)-lowering medications, with either 3 240-mL servings/d of brewed hibiscus tea or placebo beverage for 6 wk. A standardized method was used to measure BP at baseline and weekly intervals. At 6 wk, hibiscus tea lowered systolic BP (SBP) compared with placebo (-7.2 +/- 11.4 vs. -1.3 +/- 10.0 mm Hg; P = 0.030). Diastolic BP was also lower, although this change did not differ from placebo (-3.1 +/- 7.0 vs. -0.5 +/- 7.5 mm Hg; P = 0.160). The change in mean arterial pressure was of borderline significance compared with placebo (-4.5 +/- 7.7 vs. -0.8 +/- 7.4 mm Hg; P = 0.054). Participants with higher SBP at baseline showed a greater response to hibiscus treatment (r = -0.421 for SBP change; P = 0.010). No effects were observed with regard to age, gender, or dietary supplement use. These results suggest daily consumption of hibiscus tea, in an amount readily incorporated into the diet, lowers BP in pre- and mildly hypertensive adults and may prove an effective component of the dietary changes recommended for people with these conditions.
Except for conflicting evidence about coffee and risk of coronary disease, coffee and tea are not linked to major causes of death. Because of widespread use of both beverages and limitations of prior studies, concern persists. Using Cox models (ten covariates) we studied relations in 128,934 persons to 4501 subsequent deaths. Except for slightly increased risk from acute myocardial infarction among heavier (> or = 4 cups/d) coffee users (relative risk versus nondrinkers = 1.4, 95% confidence interval = 1.0 to 1.9, P = 0.07), there was no increased risk of mortality for all deaths (relative risk per cup of coffee per day = 0.99, 95% confidence interval = 0.97 to 1.01; relative risk per cup of tea per day = 0.98, 95% confidence interval = 0.96 to 1.00) or major causes in adjusted analyses. Coffee was related to lower risk of liver cirrhosis death (relative risk per cup of coffee per day = 0.77, 95% confidence interval = 0.67 to 0.89). Use of both beverages was related to a lower risk of suicide, progressively lower at higher coffee intake (relative risk per cup of coffee per day = 0.87, 95% confidence interval = 0.77 to 0.98). We conclude that coffee and tea have no overall relation to mortality risk. If coffee increases coronary risk, this is balanced by an unexplained lower risk of other conditions, notably cirrhosis and suicide.
The effect of beverages prepared from the dried calyx of the flowers of Hibiscus sabdariffa on the excretion of diclofenac was investigated using a controlled study in healthy human volunteers. A high pressure liquid chromatographic method was used to analyse the 8 h urine samples collected after the administration of diclofenac with 300 mL (equivalent to 8.18 mg anthocyanins) of the beverage administered daily for 3 days. An unpaired two-tailed t-test was used to analyse for significant difference observed in the amount of diclofenac excreted before and after administration of the beverage. There was a reduction in the amount of diclofenac excreted and the wide variability observed in the control with the water beverage of Hibiscus sabdariffa (p < 0.05). There is an increasing need to counsel patients against the use of plant beverages with drugs.
A polyphenol-rich (P-R) juice drink was developed as a potential approach to increase intake of dietary polyphenols. Analysis of the beverage by HPLC with PDA, fluorescence, and MS detection facilitated the identification/partial identification of 40 flavonoids and related phenolic compounds. The main constituents were (-)-epigallocatechin and other green tea flavan-3-ols, phloretin-2'-O-glucoside, gallic acid, hesperetin-7-O-rutinoside, 5-O-caffeoylquinic acid, and procyanidins, with trace levels of several flavonols and purple grape juice anthocyanins also being present. Healthy human subjects (n = 10) consumed 350 mL of the P-R juice drink, after which plasma and urine samples were collected over a 0-24 h period. HPLC-MS analysis identified 13 metabolites in plasma and a further 20 in urine. Qualitatively, the profiles of the glucuronide, sulfated, and methylated metabolites were very similar to those detected in earlier investigations when the main components in the juice drink were consumed separately in feeding studies with coffee, green tea, orange juice, and apple cider.
Human gammadeltaT lymphocytes are a subset of T cells and are a first line of defense against microbes and tumors. These gammadeltaT cells can be primed by nitrogen-containing bisphosphonates, and certain short-chain alkylamines. These primed gammadeltaT cells have an enhanced capacity to proliferate and to secrete cytokines upon ex vivo exposure to a wide variety of microbes and tumor cells. The largest dietary source of alkylamines is L-theanine, an amino acid unique to tea beverages that is catabolized to ethylamine. Supplementation of subjects with capsules containing L-theanine and catechins has recently been shown to decrease the incidence of cold and flu symptoms, while enhancing gammadeltaT cell function.