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PubMed1996

Maternal caffeine consumption and spontaneous abortion: a prospective cohort study.

We investigated the relation between caffeine beverage consumption and spontaneous abortion in 2,967 pregnant women planning to deliver at Yale-New Haven Hospital in 1988-1992. We evaluated coffee, tea, and soda drinking in the first month of pregnancy in interviews before the end of the sixteenth week of gestation. We obtained information on 98.2% of the pregnancies (including 2,714 singleton livebirths and 135 spontaneous abortions). As compared with abstention from caffeine beverages (coffee, tea, and soda), the adjusted odds ratios for spontaneous abortion associated with consumption of 1-150, 151-300, and > 300 mg caffeine daily were 0.81 [95% confidence interval (CI)) = 0.54-1.20], 0.89 (95% CI = 0.48-1.64), and 1.75 (95% CI = 0.88-3.47), respectively. Drinking > or = 3 cups of tea or coffee was associated with elevated risks of spontaneous abortion (adjusted odds ratio = 2.33, 95% CI = 0.92-5.85; and adjusted odds ratio = 2.63, 95% CI = 1.29-5.34, respectively). These results, if replicated, suggest that some ingredient (or correlate) of tea or coffee may account for some of the observed association of caffeine with spontaneous abortion. In this study, caffeine consumption is more strongly related to spontaneous abortion than alcohol or cigarette use in early pregnancy.

Abortion, Spontaneous↗
PubMed2004

Epidemiological studies of tooth wear and dental erosion in 14-year old children in North West England. Part 2: The association of diet and habits.

OBJECTIVE: To determine the strength of association (expressed as Odds Ratios) of potential risk factors with erosion and tooth wear in 14-year-old schoolchildren. DESIGN: A random sample of 2,385 children were selected by a stratified two-stage technique based on schools and children. SETTING: Schools in NW England. METHODS: Tooth wear was assessed by one examiner on three surfaces of all 12 anterior teeth (labial, incisal and palatal) and the occlusal surface of all four first molars using a four-point scale. Enamel wear was scored 0, dentine exposure <1/3 scored 1, >1/3 scored 2 and secondary dentine or pulpal exposure, scored 3. A questionnaire enquired about general health, dental health, habits and the frequency of intake of a wide range of foods and drinks. RESULTS: The Odds Ratios for tooth wear on any surface for habits, reflux and certain foods were: bruxism, 1.10; stomach upset, 1.45; pickles 1.86; vinegar 1.36; salt and vinegar crisps 1.33; brown/other sauces 1.57. Similarly, the odds ratios for potentially erosive drinks were: fizzy drinks 1.32; sport drinks 1.58; herbal/lemon tea 3.97. The frequency of intake was bi-modal with 397 children drinking a can per day and 207 drinking two cans per day. A significant number drank acidic beverages at bedtime but this was not associated with dental erosion. CONCLUSION: Although odds ratios greater than unity indicate an association, this was not high for carbonated beverages and many other acidic foods or drinks. Examining at fourteen years may not be ideal, as the determinants of erosion/tooth wear have not acted for long, the indices do not discriminate sufficiently and proportionately few subjects have dentine exposed on smooth surfaces.

Adolescent↗
PubMed1991

[Preventive effects of green tea extract on lipid abnormalities in serum, liver and aorta of mice fed a atherogenic diet].

This study examined the preventive effects of green tea extract on hyperlipidemia and lipid accumulation in the liver and aorta of mice fed an atherogenic diet enriched with 1.5% cholesterol, 0.5% cholic acid and 5% linoleic acid for a period of 14 weeks. The animals were given green tea extract in drinking water at doses of 50, 100 and 200 mg/kg/day. Treatment with green tea extract prevented the increase of serum cholesterol induced by the atherogenic diet 6 weeks after the start of the experiment. The increase of serum lipid peroxides was markedly prevented in a dose-related manner. The green tea extract also tended to prevent the increase of serum phospholipid and the decline of lecithin: cholesterol acyltransferase, but could not prevent decreases in serum triglycerides and high-density lipoprotein cholesterol. As for liver cholesterol, its content, particularly free cholesterol, in mice fed the atherogenic diet could be prevented from increasing by treatment with the extract at 50 and 100 mg/kg/day. In addition, the increase of aortic cholesterol, particularly esterified cholesterol, could be prevented in a dose-related manner. These results suggest that green tea has anti-atherosclerotic activity.

Animals↗
PubMed1989

Effect of consumption of green and black tea on the level of various enzymes in rats.

Drinking of both green and black tea as the only liquid ingested resulted in significant decreases in the activity of transketolase in whole blood of rats both before and after the in vitro addition of thiamin diphosphate. Liver transketolase activity was decreased only by green tea. Mucosal transketolase activity was not affected by either type of tea. The activity of lactate dehydrogenase (LDH) was not affected by either type of tea, while whole blood LDH was decreased by both green and black tea. Neither tea had any affect on mucosal alkaline phosphatase, but thiamin diphosphatase activity was decreased by both teas. An increase in liver total thiamin resulted from the drinking of both types of tea.

Alkaline Phosphatase↗
PubMed2003

Aluminium and fluoride contents of tea, with emphasis on brick tea and their health implications.

Tea plant takes up a large quantity of aluminium (Al) and fluoride (F) from acidic soils. It has been known that fluorosis can be developed for people who consume a large quantity of tea made from brick tea, a low quality tea consisting mainly of old tea leaves in China. In addition, it has been claimed that Alzheimer's disease (AD) is linked with the Al content in the human brain. Therefore, the high Al content in tea, especially brick tea is also a concern. This article reviews the basis background on tea including classification, growth conditions, types of tea leaves and their production, and processing of tea. Special emphasis is made on the transfer of Al and F from soil to tea plant and then to tea liquor. Health implications of drinking a large quantity of tea liquor especially those made from brick tea are discussed. Recommendations are suggested to reduce the uptake of these two elements by tea plant, and lower their contents in tea products.

Aluminum↗
PubMed2002

Inhibition of 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral carcinogenesis in hamsters by tea and curcumin.

Tea is one of the most popular beverages consumed in the world. Curcumin, the major yellow pigment in turmeric, is used widely as a spice and food-coloring agent. In this study, we studied the effects of tea and curcumin on 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral carcinogenesis in hamsters. DMBA solution (0.5% in mineral oil, 0.1 ml) was applied topically to the left cheek pouch of male Syrian golden hamsters 3 times/week for 6 weeks. Two days after the last treatment of DMBA, the animals received green tea (6 mg tea solids/ml) as drinking fluid, or 10 mmol curcumin applied topically 3 times/week, or the combination of green tea and curcumin treatment, or no treatment for 18 weeks. The combination of tea and curcumin significantly decreased the oral visible tumor incidence from 92.3% (24/26) to 69.2% (18/26) and the squamous cell carcinoma (SCC) incidence from 76.9% (20/26) to 42.3% (11/26). The combination of tea and curcumin also decreased the number of visible tumors and the tumor volume by 52.4 and 69.8%, as well as the numbers of SCC, dysplasic lesions and papillomas by 62.0, 37.5 and 48.7%, respectively. Green tea or curcumin treatment decreased the number of visible tumors by 35.1 or 39.6%, the tumor volume by 41.6 or 61.3% and the number of SCC by 53.3 or 51.3%, respectively. Green tea also decreased the number of dysplasic lesions. Curcumin also significantly decreased the SCC incidence. Tea and curcumin, singly or in combination, decreased the proliferation index in hyperplasia, dysplasia and papillomas. Only the combination treatment decreased the proliferation index in SCC. Tea alone and in combination with curcumin significantly increased the apoptotic index in dysplasia and SCC. Curcumin, alone and in combination with tea, significantly inhibited the angiogenesis in papilloma and SCC. The results suggested that green tea and curcumin had inhibitory effects against oral carcinogenesis at the post-initiation stage and such inhibition may be related to the suppression of cell proliferation, induction of apoptosis and inhibition of angiogenesis.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2004

Green tea modulation of the biochemical and electric properties of rat liver cells that were affected by ethanol and aging.

The oxidative stress induced by chronic ethanol consumption, particularly in concert with the aging process, has been implicated in changes in the structure and functions of liver cell components including membrane phospholipids. To counteract such changes, particularly those resulting from lipid peroxidation, antioxidants may be applied. Green tea contains large amounts of polyphenols, mainly catechins, which possess antioxidant properties. The aim of this study was to estimate the efficacy of green tea's influence on the physicochemical and biochemical properties of the rat liver as affected by the aging process and/or chronic ethanol intoxication. Several methods were used to evaluate this effect. Antioxidant properties were evaluated by vitamin E and antioxidant status determination. The liver trigliceride and cholesterol levels were also estimated. The extent of lipid peroxidation was determined by measuring the level of lipid peroxidation products as thiobarbituric reactive substances (TBARS). The surface charge density of the rat liver cells was measured using electrophoresis. The concentration of the marker enzymes of liver damage (alanine aminotransferase and aspartate aminotransferase) in the blood serum was also evaluated. Relative to the controls, aging was found to cause a decrease in the liver's antioxidant abilities and provoke an increase in the level of lipid peroxidation; it also increased the surface charge density of the rat liver cell membrane. Ethanol significantly aggravated these changes. This might have resulted in the liver cell membrane damage visible as a leak of alanine aminotransferase and aspartate aminotransferase into the blood. The ingestion of green tea with ethanol partially prevented these aging and/or ethanol-induced changes. Long-term drinking of green tea partially prevents the changes in the structure and function of the cell membrane caused by chronic ethanol intoxication.

Aging↗
PubMed2005

Food sources and intakes of caffeine in the diets of persons in the United States.

This study provides information on the caffeine intakes of a representative sample of the US population using the US Department of Agriculture 1994 to 1996 and 1998 Continuing Survey of Food Intakes by Individuals. The percentage of caffeine consumers of the total sample (N=18,081) and by age and sex groups and for pregnant women were determined. Among caffeine consumers (n=15,716), the following were determined: mean intakes of caffeine (milligrams per day and milligrams per kilogram per day) for all caffeine consumers, as well as for each age and sex group and pregnant women; mean intakes (milligrams per day) of caffeine by food and beverage sources; and the percent contribution of each food and beverage category to total caffeine intake for all caffeine consumers, as well as each age and sex group and pregnant women. Eight-seven percent of the sample consumed food and beverages containing caffeine. On average, caffeine consumers' intakes were 193 mg caffeine per day and 1.2 mg caffeine per kilogram of body weight per day. As age increased, caffeine consumption increased among people aged 2 to 54 years. Men and women aged 35 to 64 years were among the highest consumers of caffeine. Major sources of caffeine were coffee (71%), soft drinks (16%), and tea (12%). Coffee was the major source of caffeine in the diets of adults, whereas soft drinks were the primary source for children and teens.

Adolescent↗
PubMed1995

Stability of ondansetron hydrochloride injection in various beverages.

The stability of ondansetron hydrochloride injection in beverages likely to be acceptable to patients was studied. Ondansetron hydrochloride injection (containing ondansetron 2 mg/mL) was added to apple juice, fruit punch, cherry-flavored drink, carbonated soft drinks, and hot tea to provide a nominal ondansetron concentration of 32.8, 64.5, or 95.2 micrograms/mL. Samples were stored at -3 to 28 degrees C (noncarbonated-beverage mixtures except tea), 2 to 28 degrees C (carbonated-beverage mixtures), and 25 degrees C (tea) and assayed for ondansetron concentration by high-performance liquid chromatography at 6, 24, 48, and 72 hours (noncarbonated-beverage mixtures except tea); 6, 24, and 48 hours (carbonated-beverage mixtures); and 1 hour (tea). More than 95% of the initial ondansetron concentration was retained in apple juice, fruit punch, cherry-flavored drink, Sprite, and Diet Coke throughout the periods studied. A precipitate formed immediately after ondansetron was added to hot tea, but the drug was chemically stable for at least one hour in this preparation. Ondansetron hydrochloride injection 32.7, 64.5, and 95.2 micrograms/mL (expressed as free base) was stable in various beverages when stored at -3 to 28 degrees C for up to 72 hours. Ondansetron at these same concentrations precipitated in hot tea preparations but was chemically stable for at least one hour.

Anti-Anxiety Agents↗
PubMed2003

Fluoride and aluminium concentrations of tea plants and tea products from Sichuan Province, PR China.

Some Tibetans in Sichuan Province in southwestern China have been suffering from fluorosis, due to drinking and eating tea with high fluoride (F) and aluminium (Al) contents. Tea plants, soils of tea plantations and tea products from Yaan, Gaoxian and Yibin Cities in Sichuan Province were investigated to evaluate the factors affecting F and Al contents in tea products. The F and Al concentrations of four commercial brands of brick teas were significantly higher than those of 11 brands of green teas. Chemical analysis indicated that total and available F and Al concentrations in tea plantation soils in Yaan and Gaoxian were within the normal range compared with acid soils in South China and tea soils in Fujian Province. Edaphic conditions did not contribute to the high F and Al concentrations in brick tea. Analysis of raw materials of brick tea indicated that old leaves were the major contributors to the high F and Al contents contained in brick tea. There were also great variations among different tea varieties in accumulating F and Al, and concentrations of F and Al in tea variety of Qianmei 303 were about 2-3-fold higher than the other three varieties. Selection of appropriate varieties would be important to lower F and Al contents in tea products.

Aluminum↗
PubMed1980

[Atropine poisoning from "health tea"].

A description of the case of a 57 year old woman is given who showed the symptoms of an atropine poisoning after drinking stinging nettle tea. The analyses of the tea specimen proved bad defilements among other things with elements of the "belladonna" (Atropa belladonna). Several similar reports became known recently and it seems to be necessary to discuss checking the purity of the tea species.

Atropine↗
PubMed2002

[Chemopreventive effect of tea and curcumin on DMBA-induced oral carcinogenesis in hamsters].

0.5% DMBA solution (in mineral oil) was applied topically to the left cheek pouch of male Syrian golden hamsters 3 times per week for 6 weeks. After the last treatment of DMBA, the animals received 0.6% green tea powder as drinking fluid, or 10 mumol curcumin applied topically 3 times per week, or the combination of green tea and curcumin treatment, or no treatment for 18 weeks. The combination of tea and curcumin significantly decreased the oral visible tumor incidence and the squamous cell carcinoma (SCC) incidence. The combination of tea and curcumin also decreased the number of visible tumors and the tumor volume as well as the numbers of SCC, dysplasic lesions, and papillomas respectively. Green tea or curcumin treatment decreased the number of visible tumor, the tumor volume and the number of SCC respectively. Green tea also decreased the number of dysplasic lesions. Curcumin also significantly decreased the SCC incidence. Tea and curcumin, singly or in combination decreased bromodeoxyuridine (BrdU)-labeling index in hyperplasia, dysplasia, and papillomas. Tea alone and in combination with curcumin significantly increased the apoptotic index in dysplasia and SCC. Curcumin alone and in combination with tea inhibited the angiogenesis in papilloma and SCC. The results suggested that green tea and curcumin had inhibitory effects against oral carcinogenesis at the post-initiation stage and such inhibition may be related to the suppression of cell proliferation, induction of apoptosis, and inhibition of angiogenesis.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2005

Protective effect of green tea on erythrocyte membrane of different age rats intoxicated with ethanol.

It is known that aging is characterized by changes in cell metabolism resulting in modification of the structure and function of cell membrane components which is mainly the consequence of reactive oxygen species action. These disturbances are also enhanced by different xenobiotics, e.g. ethanol. Therefore, the aim of this paper is to examine green tea influence on total antioxidant status (TAS) and on composition and electric charge of erythrocyte membrane phospholipids in ethanol intoxicated rats of various ages. Antioxidant abilities of erythrocytes were estimated by measuring TAS. Qualitative and quantitative composition of phospholipids in the membrane was determined by HPLC, while the extent of erythrocytes lipid peroxidation was estimated by HPLC measurement of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) levels. Electrophoresis was used to determine the surface charge density of the rat erythrocyte membrane. It was shown that the process of aging was accompanied by a decrease in TAS and in the total amount of phospholipids as well as by enhancement of lipid peroxidation and increase in surface charge density of erythrocyte membrane. Ethanol administration caused, in term, decrease in TAS and increase in the level of all phospholipids and lipid peroxidation products. Ethanol as well significantly enhanced changes in surface charge density of erythrocyte membrane. The ingestion of green tea partially prevented decrease in erythrocyte antioxidant abilities observed during aging and ethanol intoxication. Moreover, long-term drinking of green tea protects the structure of the erythrocytes membrane disturbed during aging process and/or chronic ethanol intoxication.

Aging↗
PubMed2001

Effects of green tea on colonic aberrant crypt foci and proliferative indexes in rats.

The present study was designed to investigate the effect of green tea on 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) formation in Wistar rats. Forty-five male weanling Wistar rats were randomly divided into three groups. Rats in Group 1 were injected with DMH (20 mg/kg s.c.) once a week for 10 weeks. Animals in Group 2 received 2% green tea water extract as the sole source of drinking fluid in addition to the same treatment used for Group 1. Group 3 was the negative control group. Animals were killed at the end of Week 16 after the first DMH treatment. ACF were formed in animals in their DMH-treated groups at the end of Week 16. Group 2 had fewer ACF than Group 1. Compared with the positive control group, proliferating cell nuclear antigen labeling index, silver-stained nucleolar organizer regions, and ras-p21 expression were significantly reduced in Group 2. It was concluded that green tea drinking inhibited ACF formation in rats, and such effects may be related to the suppression of cell proliferation in the intestinal crypts.

1,2-Dimethylhydrazine↗
PubMed1997

Probable gastrointestinal toxicity of Kombucha tea: is this beverage healthy or harmful?

Kombucha tea is a health beverage made by incubating the Kombucha "mushroom" in tea and sugar. Although therapeutic benefits have been attributed to the drink, neither its beneficial effects nor adverse side effects have been reported widely in the scientific literature. Side effects probably related to consumption of Kombucha tea are reported in four patients. Two presented with symptoms of allergic reaction, the third with jaundice, and the fourth with nausea, vomiting, and head and neck pain. In all four, use of Kombucha tea in proximity to onset of symptoms and symptom resolution on cessation of tea drinking suggest a probable etiologic association.

Basidiomycota↗
PubMed2003

Lack of association between tea and cardiovascular disease in college alumni.

BACKGROUND: Epidemiological studies suggest that tea intake, a major dietary source of flavonoids, may be associated with a decreased risk of cardiovascular disease (CVD). METHODS: We prospectively followed 17 228 subjects (mean age, 59.5 years) initially free of CVD and cancer from the College Alumni Health Study. Participants provided baseline self-reports of tea consumption (cups/day) and coronary risk factors. During a median follow-up of 15 years, there were 3372, 2615, and 757 cases of CVD, coronary heart disease (CHD), and stroke, respectively, ascertained from either self-reports or death certificates. RESULTS: Overall, the median level of tea consumption was 1 cup/day. Compared with participants consuming no tea, the multivariate relative risks (RR) of CVD for those drinking <1, 1, 2, 3, and >/=4 cups/day were 0.99, 0.96, 0.95, 0.91, and 0.95, respectively (P, trend = 0.19). The multivariate RR were 0.97, 0.98, 0.93, 0.85, and 0.98 for CHD (P, trend = 0.25), and 1.05, 0.89, 1.00, 1.09, and 0.83 for stroke (P, trend = 0.53). There was no evidence of effect modification. Changes in tea intake were assessed in a subgroup of 7730 men, with those continuing to drink tea having a non-significant 33% reduction in the risk of stroke. CONCLUSIONS: Tea intake, likely consumed as black tea, was not strongly associated with a reduced risk of CVD in this population of US college alumni.

Cardiovascular Diseases↗
PubMed2006

Beverage intake, diabetes, and glucose control of adults in America.

PURPOSE: Beverages are important components of diet and a route for the intake of caffeine, ethanol, and other bioactive substances. The aim of the study is to examine the association between type of beverages consumed and glucose control in American adults with and without diabetes. METHODS: Diabetes status, glycosylated hemoglobin (hemoglobin A1c [HbA1c]) level, and 1-month recall food frequency questionnaires were all collected in the Third National Health and Nutrition Examination Survey (1988 to 1994), based on a nationally representative sample of the noninstitutionalized civilian US population. We used regression and other methods for clustered data to examine the association of HbA1c levels with self-reported intake of carbonated drinks, alcohol, coffee, tea, juices, and milk in participants aged 18 to 75 years with and without diabetes. RESULTS: Adults with diabetes reported drinking half the amount of alcohol as adults without diabetes. Compared with nondrinkers, subjects who had 30 or more drinks per month of alcohol had mean HbA1c levels 1.2 units less (p < 0.001) in persons with diabetes and 0.2% less (p < 0.001) in persons without diabetes. Adults with diabetes reported drinking three times as much diet soda as adults without diabetes. However, in adults with diabetes who had one or more drinks of diet soda per day, HbA1c level was 0.7 units greater (p < 0.001) compared with those who drank none. CONCLUSIONS: Alcohol consumption, at least in moderate amounts, correlates with better glucose control. There is a correlation between drinking diet soda and glucose control in adults with diabetes.

Adult↗
PubMed2004

Pharmacological effects of green tea on the gastrointestinal system.

Green tea is rich in polyphenolic compounds, with catechins as its major component. Studies have shown that catechins possess diverse pharmacological properties that include anti-oxidative, anti-inflammatory, anti-carcinogenic, anti-arteriosclerotic and anti-bacterial effects. In the gastrointestinal tract, green tea was found to activate intracellular antioxidants, inhibit procarcinogen formation, suppress angiogenesis and cancer cell proliferation. Studies on the preventive effect of green tea in esophageal cancer have produced inconsistent results; however, inverse relationships of tea consumption with cancers of the stomach and colon have been widely reported. Green tea is effective to prevent dental caries and reduce cholesterols and lipids absorption in the gastrointestinal tract, thus benefits subjects with cardiovascular disorders. As tea catechins are well absorbed in the gastrointestinal tract and they interact synergistically in their disease-modifying actions, thus drinking unfractionated green tea is the most simple and beneficial way to prevent gastrointestinal disorders.

Anticarcinogenic Agents↗