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PubMed2004

Antioxidants of the beverage tea in promotion of human health.

Tea that contains many antioxidants is a pleasant and safe drink that is enjoyed by people across the globe. Tea leaves are manufactured as black, green, or oolong. Black tea represents approximately 78% of total consumed tea in the world, whereas green tea accounts for approximately 20% of tea consumed. The concept of "use of tea for promotion of human health and prevention and cure of diseases" has become a subject of intense research in the last decade. Diseases for which tea drinkers appear to have lower risk are simple infections, like bacterial and viral, to chronic debilitating diseases, including cancer, coronary heart disease, stroke, and osteoporosis. Initial work on green tea suggested that it possesses human health-promoting effects. In recent years, the research efforts have been expanded to black tea as well. Research conducted in recent years reveals that both black and green tea have very similar beneficial attributes in lowering the risk of many human diseases, including several types of cancer and heart diseases. For cancer prevention, evidence is so overwhelming that the Chemoprevention Branch of the National Cancer Institute has initiated a plan for developing tea compounds as cancer-chemopreventive agents in human trials. Thus, modern medical research is confirming the ancient wisdom that therapy of many diseases may reside in an inexpensive beverage in a "teapot."

Animals↗
PubMed2000

Sources of dietary fluoride intake in 4-year-old children residing in low, medium and high fluoride areas in Iran.

Accurate estimation of fluoride dietary intake is desirable for optimising caries prevention. Little is known about the dietary fluoride intake of children aged 4 years, an age when many permanent teeth are forming. This study was undertaken in Fars Province, Iran, in 1995-1996, where there are big differences in temperature between winter and summer. The aims were to determine: (a) the relative contributions of different components of the diet to fluoride intake, (b) the effect of variation in fluoride concentration in drinking water, and (c) the effect of climate temperature. Temperature varied between +40 degrees C in summer to -5 degrees C in winter. The mean fluoride concentrations in drinking water in the three areas were 0.3, 0.6 and 4.0 mgF/L. Dietary information was obtained by two 3-day diet diaries with interview, validated with reference to international standards. The fluoride content of foods was measured using the silicon-facilitated diffusion method. One hundred and three 4-year-old children completed the study. The mean (and 95% confidence interval) dietary fluoride intakes in each of the three areas, respectively, were 413 (+/- 21), 698 (+/- 89) and 3472 (+/- 557) micrograms/day. Drinks provided 72 to 87% of dietary fluoride--this proportion increased with increasing water fluoride concentration and increasing climate temperature. Tea (infusion) was an important source of dietary fluoride, providing 31 to 38% of total dietary intake. Tap water was a more important source of fluoride than soft drinks. Cooked rice and bread were the most important food source of fluoride and the amount of fluoride they contributed increased as water fluoride concentration increased. The results of this first such survey in the Middle East showed (a) that water (as a drink) and tea were by far the most important contributors to dietary fluoride intake, (b) substantial increases in fluoride intake with increasing water fluoride concentrations, and (c) substantially higher fluoride intakes in summer than in the winter.

Beverages↗
PubMed1991

The effect of tea on iron and aluminium metabolism in the rat.

Weanling male Wistar rats were fed for 28 d on a semi-synthetic diet containing normal (38 micrograms/g) or low (9 micrograms/g) levels of iron. They were given water or tea infusion (20 g leaves/l water) to drink. Two further groups were given a normal- or low-Fe diet containing added tea leaves (20 g/kg diet). At the end of the study period, all rats given the low-Fe diet were severely anaemic, as assessed by haemoglobin, packed cell volume and liver Fe. Those given tea or the diet with added tea leaves showed a greater degree of Fe depletion. The blood and liver aluminium levels were not increased as a result of consuming tea or tea leaves, despite the higher Al intakes. Fe deficiency per se had no effect on Al absorption or retention from tea. It was concluded that the Al in tea was very poorly absorbed but that tea, either in the form of an infusion or as tea leaves, had an adverse effect on Fe status.

Aluminum↗
PubMed2000

A naturalistic investigation of the effects of day-long consumption of tea, coffee and water on alertness, sleep onset and sleep quality.

RATIONALE: The effects of caffeine, especially caffeinated coffee, on human performance have been extensively studied. However, few studies have been naturalistic representations of how tea/coffee is normally consumed in terms of dose and time of consumption. OBJECTIVES: This study investigated the effects of day-long consumption of tea, coffee and water on cognitive and psychomotor performance, and sleep quality at night. METHODS: Thirty healthy volunteers received equal volume drinks equivalent to either 1 or 2 cups of tea (containing 37.5 mg or 75 mg caffeine), or coffee (75 mg or 150 mg caffeine), or water, in a randomised five-way crossover design. Drinks were administered on four occasions during the day (0900, 1300, 1700 and 2300 hours). A psychometric battery consisting of critical flicker fusion (CFF), choice reaction time (CRT) and subjective sedation (LARS) tests, was administered pre-dose and at frequent time points post-dose. The Leeds Sleep Evaluation Questionnaire (LSEQ) was completed each morning and a wrist actigraph was worn for the duration of the study. RESULTS: Caffeinated beverages maintained CFF threshold over the whole day (P<0.05), independent of caffeine dose or beverage type. During the acute phase of beverage ingestion, caffeine significantly sustained performance compared to water after the first beverage for CFF and subjective sedation (P<0.05), and after the second beverage for the Recognition component of the CRT task (P<0.05). Additionally, there were significant differences between tea and coffee at 75 mg caffeine after the first drink. Compared to coffee, tea produced a significant increase in CFF threshold between 30 and 90 min post-consumption (P<0.01). However, following the second beverage caffeinated coffee at 75 mg significantly improved reaction time (P<0.05), compared to tea at the same dose, for the Recognition component of the CRT task. Caffeinated beverages had a dose dependent negative effect on sleep onset (P<0.001), sleep time (P<0.001) and sleep quality (P<0.001). CONCLUSIONS: These results indicate that ingestion of caffeinated beverages may maintain aspects of cognitive and psychomotor performance throughout the day and evening when caffeinated beverages are administered repeatedly. This study also demonstrates that day-long tea consumption produces similar alerting effects to coffee, despite lower caffeine levels, but is less likely to disrupt sleep. Other differences between tea and coffee were more subtle, and require further investigation.

Adult↗
PubMed1998

[Development of antiviral therapeutic agents from traditional medicines].

Traditional medicines contain various metabolites derived from nucleic acid, protein, and lipid metabolism. Some of these specific metabolites may recognize the differences between viral and host metabolism resulting in anti-viral activity; hence traditional medicines may be useful sources for new antiviral agents. Traditional medicines can be cheaply obtained and have been orally administered as hot-water extracts. Therefore, they may be used for the prophylactic and therapeutic treatment of viral infection by drinking them, such as coffee or tea. Here we describe how the antiviral activity of traditional medicines was screened in vitro and how their therapeutic antiviral activities were verified in vivo, to obtain traditional antiviral medicines that can be clinically used. Therefore, we have selected 12 herbal extracts, from more than 250 herbal medicines, that exhibit therapeutic activities against cutaneous herpes simplex virus (HSV) type 1 (HSV-1) infection in mice. Four of the 12 augmented the therapeutic efficacy of acyclovir (ACV) in mice and showed potent anti-HSV activity against infection with ACV-resistant HSV-1 mutants in mice. These herbal extracts selectively inhibited viral DNA synthesis and showed a different mode of anti-HSV-1 action from that of ACV. They were also effective against both recurrent HSV and cytomegalovirus infections, without toxicity. Such prophylactic and therapeutic antiviral activities of the traditional medicines were verified by the purification of major active compounds. We could show new indications of traditional medicines as antiviral agents. Thus, the drinking of the extracts, in a daily tea or coffee, may be used for prophylaxis and therapy of diseases caused by herpes virus infection and improve the quality of life.

Animals↗
PubMed1984

Impairment of acetylcholine synthesis in thiamine deficient rats developed by prolonged tea consumption.

The synthesis of whole brain acetylcholine is reduced in thiamine deficient rats produced by prolonged administration of tea. In those rats fed a normal diet and given tea (1:50, w/v) instead of drinking water for 20 weeks, the conversion of [14C] pyruvate to [14C]acetylcholine decreased by 35%. However, no neurological symptoms were observed. Administration of tea to rats fed a thiamine half-deficient diet for 7-8 weeks caused not only 60% decrease in acetylcholine synthesis but also neurological symptoms. This decreased synthesis of acetylcholine is related to a decline in pyruvate dehydrogenase activity. The results suggest that prolonged administration of tea to rats cause an impairment of acetyl CoA production resulting in a deficit in acetylcholine synthesizing capacity.

Acetylcholine↗
PubMed1999

Proliferation of hepatic peroxisomes in rats following the intake of green or black tea.

Rats maintained on green, black or decaffeinated black tea (2.5%, w/v) as their sole drinking fluid displayed higher hepatic CN- insensitive palmitoyl CoA oxidase activity than controls; the extent of increase was similar with the three types of tea. Morphological examination of the liver using electron microscopy revealed an increase in the number of peroxisomes in the tea-treated animals. The same treatment of the animals with green and black tea resulted in a similar rise in hepatic microsomal lauric acid hydroxylation. Analysis by HPLC of the aqueous tea extracts employed in the current study showed that the total flavanol content of the green variety was much higher than the black varieties, and confirmed the absence of caffeine in the decaffeinated black tea. It may be concluded from the present studies that neither caffeine nor flavanoids are likely to be responsible for the proliferation of peroxisomes observed in rats treated with tea.

Animals↗
PubMed1997

Characterization of early pulmonary hyperproliferation and tumor progression and their inhibition by black tea in a 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced lung tumorigenesis model with A/J mice.

The pathogenesis of pulmonary tumors induced by a tobacco carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and its inhibition by black tea have been characterized. Female A/J mice (6 weeks old) were treated with a single dose of NNK (103 mg/kg of body weight, i.p.) on day 0, and the cell proliferation index was measured by the incorporation of bromodeoxyuridine (BrdUrd) immunohistochemically. The number of BrdUrd-labeled cells increased in the bronchiolar epithelium from day 2 to day 14, with the highest proliferation rate observed on day 5. By day 35, the BrdUrd-labeling index returned to the level of the control group. Further examination of the day 35 samples revealed the presence of foci of hyperproliferative cells in the bronchiolar epithelium, particularly in the bronchiolalveolar regions. These proliferating bronchiolar epithelial cells (Clara cells) may be the initiated sites for pulmonary tumorigenesis. In this short-term model, administration of black tea polyphenols (0.3%) through the drinking water starting 24 h after NNK treatment significantly inhibited NNK-induced early bronchiolar cell proliferation on day 5. In long-term studies, adenomas were observed in 100% (15 of 15) of the mice at week 16, with 7.8 +/- 0.8 tumors per mouse. At week 52, a malignant tumor incidence of 80% (41 of 51 mice) and a malignant tumor multiplicity of 2.39 +/- 0.19 were observed. The growth patterns of the malignant tumors, which included solid, papillary, and mixed types, may be associated with the cellular origin of the tumor. The cell proliferation indices, as measured by proliferating cell nuclear antigen immunohistochemistry, were significantly higher in dysplasia within adenoma than in adenoma, and significantly higher in adenoma at week 52 than in adenoma at week 16. Administration of black tea, starting 16 weeks after a single dose of NNK, inhibited the progression of adenoma to adenocarcinoma as determined by both malignant tumor incidence and multiplicity. The cell proliferation rate in adenomas was also suppressed by black tea treatment. The present work demonstrates the antiproliferative activities of black tea and its polyphenols. Such activities, at the early and late stages of lung tumorigenesis, may be important for the cancer-chemopreventive activities of black tea.

Animals↗
PubMed2006

Metabolic effects of spices, teas, and caffeine.

Consumption of spiced foods or herbal drinks leads to greater thermogenesis and in some cases to greater satiety. In this regard, capsaicin, black pepper, ginger, mixed spices, green tea, black tea and caffeine are relevant examples. These functional ingredients have the potential to produce significant effects on metabolic targets such as satiety, thermogenesis, and fat oxidation. A significant clinical outcome sometimes may appear straightforwardly but also depends too strongly on full compliance of subjects. Nevertheless, thermogenic ingredients may be considered as functional agents that could help in preventing a positive energy balance and obesity.

Animals↗
PubMed1996

Relation of green tea consumption to serum lipids and lipoproteins in Japanese men.

Animal experiments have shown a hypocholesterolemic effect of green tea extracts. Only few epidemiological studies have addressed the relation between green tea consumption and serum total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C). This paper examined the relation of green tea consumption to serum lipids and lipoproteins in 2,062 male self-defense officials in Japan, aged 49-55 years, who received a preretirement health examination at three hospitals of the Self-Defense Forces in 1991-1992. A self-administered questionnaire queried the consumption of green tea and a limited number of other dietary items as well as lifestyle characteristics. After adjustment for body mass index, waist-hip ratio, smoking, alcohol use, exercise, rank, and hospital, green tea consumption was inversely associated with serum levels of TC and LDL-C, but not with either high density lipoprotein cholesterol or triglycerides. Rice consumption was positively correlated with green tea consumption, and also was associated independently with lower levels of TC and LDL-C. Additional adjustment for rice, however, did not change the results. Daily drinking of 10 cups of green tea was associated with differences of 6.2 mg/dl in TC (95% confidence interval [CI] 0.4-12.1) and 6.2 mg/dl in LDL-C (95% CI 0.7-11.7). These findings of association of green tea with blood cholesterol hint at a possible causal relationship, which requires confirmation by further studies in humans using different methods.

Anthropometry↗
PubMed2004

Oral Kohki Tea and its protective effect against in vitro ischemic damage to the bladder.

AIMS: Results of several studies indicate that ischemia/reperfusion (I/R) is an etiological factor in the contractile dysfunctions induced by partial bladder outlet obstruction in animal models. In support of this hypothesis, pretreatment of rabbits with Kohki Tea (Engelhardtia chrysolepis), a Japanese herbal drink very high in antioxidant activity, significantly reduced the contractile dysfunctions induced by partial outlet obstruction. The current study was designed to determine if pretreating rabbits with Kohki Tea could protect the bladder against the contractile damage induced by in vitro ischemia followed by re-oxygenation. METHODS: Forty-eight New Zealand White rabbits were separated into two groups of 24; Group 1 was pretreated by oral gavage for 3 weeks with Kohki Tea and Group 2 received vehicle (water). Each rabbit was anesthetized with pentobarbital. The urinary bladder was rapidly removed and eight longitudinal muscle strips were cut from the bladder body. Each strip was mounted in a separate 15-ml bath containing Tyrode's solution with glucose (1 mg/ml) and maintained at 37 degrees C. All strips were equilibrated for 30 min with a gas mixture of 95% O2 and 5% CO2. At the end of this period of time, all strips were stimulated with field stimulation (FS) carbachol and KCl. After the last wash, the aeration was changed to hypoxic mixture (nitrogen-CO2) without glucose. At the end of 2 hr, the aeration was changed back to the normal 95% O2 and 5% CO2, and glucose was added to the buffer. After 1 hr of re-oxygenation, a second set of stimulations was performed. In order to represent hyperreflexia, the strips were stimulated at 32-Hz FS at 5-min intervals during the hypoxic period in half of the in vitro experiments. RESULTS: The results showed that Kohki Tea pretreatment protected the bladder's response to FS from the detrimental effects of repetitive stimulation and the detrimental effects of both in vitro ischemia and repetitive stimulation on the contractile responses to carbachol and KCl. CONCLUSIONS: These data are consistent with the concept that Kohki Tea acts by protecting the bladder from cellular damage caused by hypoxia and the generation of free radicals.

Administration, Oral↗
PubMed1992

Inhibition of tobacco-specific nitrosamine-induced lung tumorigenesis in A/J mice by green tea and its major polyphenol as antioxidants.

In this study we examined the effects of green tea and its major components, (-)-epigallocatechin gallate (EGCG) and caffeine, on the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis in A/J mice. We also studied the effects of green tea and EGCG on O6-methylguanine and 8-hydroxydeoxyguanosine (8-OH-dGuo) formation in lung tissues caused by NNK treatment. Mice were given 2% tea, 560 ppm EGCG, or 1120 ppm caffeine in drinking water for 13 weeks. During this time, NNK (11.65 mg/kg body weight) was administered by gavage three times weekly for 10 weeks from weeks 3 to 12. The bioassay was terminated 6 weeks after the last NNK treatment. Mice treated with NNK developed 22.5 lung adenomas per mouse, whereas NNK-treated mice that drank green tea or EGCG as drinking water developed only 12.2 (P less than 0.01) and 16.1 (P less than 0.05) tumors per mouse, respectively. Mice that drank green tea or caffeine solution showed lower body weight gains, although little difference in water and diet consumption was noted in these groups. While green tea and EGCG exerted little effect on the formation of O6-methylguanine, a critical DNA lesion in NNK lung tumorigenesis, both treatments suppressed the increase of 8-OH-dGuo levels in mouse lung DNA. The inhibition of 8-OH-dGuo formation in lung DNA by green tea and EGCG is consistent with their ability to inhibit lung tumorigenesis by NNK. Because 8-OH-dGuo is a DNA lesion caused by oxidative damage, these results suggest that the mechanism of inhibition by green tea and EGCG in NNK-induced lung tumorigenesis is due at least partly to their antioxidant properties.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1997

A frequency survey of sugary foods and drinks consumption in school children and adolescents in a West Indian island--Antigua.

In 1991, the pattern of sugar consumption in samples of 172 12-year-old children and 231 15-19-year-old adolescents was studied. Twenty-four hour dietary records of five consecutive days were obtained from each subject. The frequency of total sugary food and drink episodes for children was 3.16 and 3.71 for adolescents. This was mainly accounted for by the consumption of sugary items at meals for both age groups. Students mostly consumed sweetened drinks at meals, especially at breakfast and ate sugary foods between meal times, particularly between lunch and dinner. Sweetened tea and juice were the most popular drinks and confectionery was the most popular snack food.

Adolescent↗
PubMed1992

Food and health at the time of Rubens A lecture given at the ESPEN Congress, Antwerp 1991.

The Renaissance period in Europe saw many dietary changes due to imports of new ingredients from the Far East as well as from newly discovered Central and South America. Maize and potatoes rapidly conquered European markets and because of their easier cultivation and higher calorie content, displaced grains such as wheat and rye. Drinking habits too changed, when tea, coffee and chocolate were introduced, first as strengthening medicines, later as 'délicatesses' in the aristocratic British and French cafés. These new foods and beverages may have helped diminish the periods of famine typical of Medieval and Early Renaissance times. In the 16th and 17th century, new diseases were described that were directly related to dietary intake. Ergotism and scurvy, particularly, sometimes decimated whole populations in rural areas or at sea. It was not until the 18th century that scientific research elucidated the cause of such diseases and helped us to understand the importance of a balanced diet.

Journal Article↗
PubMed2000

Antioxidant actions of du-zhong (Eucommia ulmoides Oliv.) toward oxidative damage in biomolecules.

This study aimed to investigate the antioxidant effect of water extracts of Du-zhong (WEDZ) on oxidative damage in biomolecules such as deoxyribose, DNA, and 2'-deoxyguanosine (2'-dG) as induced by Fenton reaction. The WEDZ used included leaves, raw cortex, and roasted cortex. All of the WEDZ inhibited the oxidation of deoxyribose induced by Fe(3+)-EDTA/H2O2/ascorbic acid in a concentration dependent manner. At a concentration of 1.14 mg/mL, the inhibitory effect of the extracts of leaves, roasted cortex, and raw cortex was 85.2%, 68.0% and 49.3%, respectively. The extract of leaves inhibited the strand-breaking of DNA induced by the Fenton reaction at concentrations of 5 and 10 micrograms/microL. This inhibitory effect was similar to mannitol whereas the extracts of raw cortex and roasted cortex had no inhibitory effect at all. WEDZ also inhibited the oxidation of 2'-dG to 8-OH-2'-dG induced by Fe(3+)-EDTA/H2O2/ascorbic acid. Gallic acid had a prooxidant effect, but trolox and mannitol had an antioxidant effect. The leaf extract had a marked inhibitory effect on Fenton reaction induced oxidative damage in biomolecules. The extract of roasted cortex exhibited modest inhibition while the extract of raw cortex had the least inhibitory effect on oxidative damage in biomolecules. This is in contrast to gallic acid in the same reaction system, whose higher reducing power and weaker chelating ability may contribute to its prooxidant effect. In the present study, leaf extract of Du-zhong had inhibitory effect on oxidative damage in biomolecules. Therefore, drinking of Du-zhong tea (leaf extract) over a long period of time may have anticancer potential.

Antibiotics, Antineoplastic↗
PubMed2004

Commercial and laboratory extracts from artichoke leaves: estimation of caffeoyl esters and flavonoidic compounds content.

Artichoke leaf extracts are widely used alone or in association with other herbs for embittering alcoholic and soft drinks and to prepare herbal teas or herbal medicinal products. Despite this wide diffusion, the European Pharmacopoeia does not report an official method for the determination of the active principles of artichoke leaf extracts. This work reports a quali-quantitative determination by HPLC/DAD and HPLC/MS techniques of both cynnamic acids and flavonoids present in some artichoke leaf commercial extracts (Com) compared with two different laboratory extracts (Lab). Most of the commercial extracts showed a similar quali-quantitative pattern with a single exception having five-six times higher value. The quantitative data from the Italian Pharmacopoeia(IP) official method does not evaluate the flavonoidic fraction and showed an overestimation of the caffeoyl esters with respect to the HPLC/DAD results. The proposed HPLC/DAD method was able to completely characterize and quantify this matrix and represents a contribution to better quality control of these herbal extracts.

Caffeic Acids↗
PubMed2002

Nutrition transition in Morocco.

OBJECTIVE: To analyse the nutritional transition in Morocco. DESIGN: Examination of Moroccan national survey data. RESULTS: Morocco is undergoing a demographic, epidemiological and social transition. The urban population increased from 29% in 1960 to 53% in 1997. Per capita gross domestic product increased steadily from 1972 to 1999. Life expectancy at birth increased to 70 years in 1999 from 47 years in 1962. Both infant and juvenile mortalities have decreased, from 92/1000 and 69/1000 in 1982-87 to 46/1000 and 37/1000 in 1992-97, respectively. In parallel, the diet changed considerably: the intake of animal products increased while that of cereals and sugar remained relatively high, reflecting the specificity of Moroccan dietary habits. The rise in the consumption of meats and vegetables was accompanied by a steady consumption of bread, used to eat the sauce in which the meat and vegetables are cooked. Sugar is mainly used in tea, the very sweet, national drink consumed throughout the day. Under-nourishment persists among children under five (23% stunting and 10% underweight in 1997) while overweight is rising (9% in 1997 compared with 3% in 1987 for children under three). Among adults, overweight (body mass index (BMI) > 25 kg m(-2)) increased from 26% in 1984 to 36% in 1998. It is higher among women (32% in 1984 and 45% in 1998) than among males (19% in 1984 and 25% in 1998). It is also higher among urban populations (30% in 1984 and 40% in 1998) than rural populations (20% in 1984 and 29% in 1998). Obesity (BMI > 30kg m(-2)) increased from 4% in 1984 to 10% in 1998. Overweight seems to be positively associated with economic status but negatively with education level. CONCLUSION: Overweight and obesity constitute major health problems in Morocco.

Adolescent↗