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Fluoride sources and dental attendance habits among adults in communities with optimal and low water fluoride concentrations.

The aim of this study was to obtain data on local fluoride supply, dental attendance, and dental care habits in two sociologically similar municipalities with optimal, 1.0 ppm, and low, 0.3 ppm, water fluoride concentrations, respectively. The participants in the study were 30- to 40-year-old lifetime residents in the two municipalities: 569 individuals from the 1-ppm fluoride community and 466 from the low-fluoride community. There were no intergroup differences in the fluoride mouthrinse utilization rate of 1%. Fluoride toothpaste was much more common in the low-fluoride area. In the 1-ppm fluoride area more people drank tea, and they went more regularly to the dentist. It is suggested that dental attendance habits and various fluoride sources should be taken into account in studies evaluating the effect of fluoride in drinking water.

Adult↗

[Antibacterial and bactericidal activities of Japanese green tea].

We found that extracts of Japanese green tea leaves inhibited the growth of various bacteria causing diarrheal diseases. All tea samples tested showed antibacterial activity against Staphylococcus aureus, S. epidermidis, Vibrio cholerae O1, V. cholerae non O1. V. parahaemolyticus, V. mimicus, Campylobacter jejuni and Plesiomonas shigelloides. None of the tea samples had any effect on the growth of V. fluvialis, Aeromonas sobria, A. hydrophila, Pseudomonas aeruginosa, Salmonella enteritidis, enteroinvasive Escherichia coli, enterohemorrhagic E. coli, enteropathogenic E. coli, enterotoxigenic E. coli, Enterobacter cloacae or Yersinia enterocolitica. Salmonella and Shigella showed susceptibilities different depending on the kind of Japanese green tea. Japanese green tea showed also bactericidal activity over S. aureus, V. parahaemolyticus and even enteropathogenic E. coli which was not sensitive when tested by cup method. The bactericidal activity was shown even at the drinking concentration in daily life.

Bacteria↗

The in vivo effects of cytokines modulation for BALB/C mice fed with a traditional combined chinese herb-soaked solution, Yi-Fey Ruenn-Hou tea.

An experiment was conducted to investigate the effects of Yi-Fey Ruenn-Hou (YR) Tea, a combination of Chinese herbs, 10% licorice root, 10% American ginseng, 10% Radix Paeoniae alba and 70% green tea-soaked solution, on the cytokine modulation in Balb/C mice. Four groups of mice were administered either 1ml of drinking water (group A) or 2 mg/ml (group B), 8 mg/ml (group C), 40 mg/ml (group D) of a saturated solution of combined Chinese herbs daily for six months. The physiological and pathological characteristics of the mice were observed during the time, and the mice were weighed and at least two mice were sacrificed each month for pathological detection of the brain, heart, liver, spleen and kidney and cytokine analysis. The results revealed neither weight difference nor pathological change among the four groups, however, serum-cytokine assay indicated that the cytokine modulation effects are consistent, and the most obvious cytokine modulation effect was observed in group D, which was the highest dosage employed for treating the mice. TH2-pattern cytokines responded earlier and higher in group D than in groups B and C. Furthermore, the effect of YR Tea on cytokine modulation in vivo is predominantly TH2-pattern and is dependent on its dosage (P < 0.05).

Animals↗

Arsenic-induced micronuclei formation in mammalian cells and its counteraction by tea.

The Gangetic plain of West Bengal, India, has been engulfed by a disastrous environmental calamity of arsenic contamination of the ground water. Chronic arsenic toxicity caused by drinking arsenic-contaminated water has been one of the worst health hazards gradually affecting nine districts of West Bengal since the early 1980s. Over and above hyperpigmentation and keratosis,weakness, burning sensation of the eyes, swelling of the legs, liver fibrosis, chronic lung disease, gangrene of the toes, neuropathy, and skin cancer are other manifestations. Induction of cancer is frequently associated with DNA damage, changes in ploidy of cells, and non-random chromosome aberrations. Counteraction of these genotoxic and cytogenetic abnormalities with natural dietary polyphenols could be a useful strategy to combat arsenic-induced DNA damage and thereby cancer. A review of the literature showed that it is the antioxidant property of tea polyphenols that affords protection against various types of cancer. The present study was conducted to investigate whether the extracts of green tea and black tea (Darjeeling and Assam) as well as their polyphenols could ameliorate this arsenic-induced genotoxicity. The normal mammalian cell culture derived from male Chinese hamster lung fibroblast cells (V79) was used as the test system to assess the genotoxicity by micronucleus assay. The results showed that both green tea and black tea extracts have equal potential in modulating the arsenic-induced genotoxicity. This effect was perhaps induced by the constituent polyphenols present in green and black tea. In addition, the repair activity of the damaged cells was enhanced when treated with these tea extracts and their polyphenols. Thus, tea and its polyphenols may have a promising role in counteracting the devastating effects of arsenic.

Animals↗

Coffee, tea, and caffeine consumption and risk of rheumatoid arthritis: results from the Iowa Women's Health Study.

OBJECTIVE: To evaluate whether coffee, tea, and caffeine consumption are risk factors for rheumatoid arthritis (RA) onset among older women. METHODS: These factors were evaluated in a prospective cohort study that was initiated in 1986 and that included 31,336 women ages 55-69 years without a history of RA. Risk factor data were self-reported using a mailed questionnaire. Through 1997, 158 cases of RA were identified and validated against medical records. The relative risk (RR) and 95% confidence interval (95% CI) were used as the measures of association and were adjusted for age, alcohol use, smoking history, age at menopause, marital status, and the use of hormone replacement therapy. RESULTS: Compared with those reporting no use, subjects drinking > or =4 cups/day of decaffeinated coffee were at increased risk of RA (RR 2.58, 95% CI 1.63-4.06). In contrast, women consuming >3 cups/day of tea displayed a decreased risk of RA (RR 0.39, 95% CI 0.16-0.97) compared with women who never drank tea. Caffeinated coffee and daily caffeine intake were not associated with the development of RA. Multivariable adjustment for a number of potential confounders did not alter these results. The associations of RA onset with the highest categories of decaffeinated coffee consumption (RR 3.10, 95% CI 1.75-5.48) and tea consumption (RR 0.24, 95% CI 0.06-0.98) were stronger in women with seropositive disease compared with those with seronegative disease (RR 1.54, 95% CI 0.62-3.84 and RR 0.93, 95% CI 0.27-3.20, respectively). CONCLUSION: Decaffeinated coffee intake is independently and positively associated with RA onset, while tea consumption shows an inverse association with disease onset. Further investigations of decaffeinated coffee and tea intake as arthritis risk factors are needed to verify these findings and explore their biologic basis.

Aged↗

Long-term acceptability of limited diets.

A food with long-term acceptability can be eaten one or more times a day without the consumer becoming "tired" of eating it. Few foods are eaten as often as once a day, but those that are can give us some clues about the attributes associated with long-term acceptability. Studies by the armed forces in the late 1950s showed that most foods decreased in liking when repeatedly consumed and that the rate of decline depended on the specific food. Current techniques for measuring the liking of foods (typically using a hedonic category scale) do not necessarily indicate long-term acceptability. Our data on repeated consumption of two versions of tea suggests that taste test measurements can be quite misleading. A relatively newer measurement, sensory-specific satiety, may provide a rapid method for measuring long-term acceptability.

Diet↗

Risk factors for squamous cell carcinoma of the oesophagus in women: a case-control study.

Oesophageal cancer rates in women in the UK are more than 3 times higher than in most other European populations. A population-based matched case-control study of histologically confirmed squamous cell carcinoma of the oesophagus in women was carried out in 4 regions in England and Scotland. Interviews were carried out in hospital or at home and topics included: smoking; alcohol; tea and coffee consumption; medical and obstetric history; and diet. Response rates were 62% for cases and 65% for first-chosen controls. There were 159 case-control pairs. Significant results were found for: eating salads (odds ratio (OR) 0.42, 95% CI 0.20-0.92 in the highest quartile of consumption) and a light (as distinct from no) breakfast (OR 0.18, 95% CI 0.07 - 0.48) were protective; quantity of tea was a risk factor and there was a significant positive trend with temperature at which hot drinks were consumed (P = 0.03). Alcohol consumption was unrelated to risk, but there was a significant trend with years of smoking (P = 0.015). A protective effect of aspirin consumption was confined to the English centres (OR 0.08, 95% CI 0.01-0.56). Comparison with a parallel study of adenocarcinoma indicated a common protective effect of a healthy diet but otherwise distinct risk factors.

Aged↗

Effect of eating cheese on Ca and P concentrations of whole mouth saliva and plaque.

A study was undertaken to examine the release of calcium and phosphate from cheese during mastication. Unstimulated saliva was collected for baseline analysis in the initial study followed by saliva collection after chewing different cheeses with and without biscuits. In the second study, volunteers who had abstained from tooth cleaning for 24 h had plaque samples taken from two quadrants, they then chewed cheese in their own personal eating manner, and a second sample of plaque was taken within 5 min. The results showed that the calcium ion concentration of the oral fluids rose from a mean of 30 micrograms/ml to between 200 and 540 micrograms/ml, depending on the type of cheese, but the phosphate concentration fell below baseline. The release of both ions tended to be less when the cheese was eaten with a biscuit. In the second study a highly significant rise in plaque calcium concentration was shown after eating cheese, but no consistent change in phosphate level was found. Acidic soft drinks, following eating, tended to reduce the plaque calcium levels, but no consistent change was found if tea or coffee was taken following the cheese consumption. It is suggested, from these findings, that cheese eaten alone at the very end of a meal raises plaque calcium and might be effective in reducing dental caries.

Beverages↗

Dietary habits of school-children in Bahrain.

A multistage stratified sampling procedure was used to select 1673 Bahraini school children (871 boys and 802 girls) to study their food habits. The results revealed that breakfast was more often skipped than lunch and supper by both sexes. Significant differences in the food consumption between boys and girls were noticed at morning snack; beef burgers, liver and egg sandwiches were more consumed by boys, while girls preferred carbonated beverages, cheese, uncarbonated canned drinks and broad beans. The foods consumed at lunch were very similar to those of the adult population in Bahrain. However, the percentage of fresh fruits consumed at lunch was almost double by girls (31.9%) than boys (17.1%). Corn-puffs, carbonated beverages, chocolates, uncarbonated canned drinks and fruits were the main foods consumed at afternoon snack. Boys were more likely to consume tea, meat, eggs, cheese and rice at supper, while girls preferred cheese, corn-puffs and carbonated beverages. Age has also a significant influence on dietary habits. The consumption of bread at breakfast decreased with age while the consumption of carbonated beverages at morning snack increased remarkably with age. In general the meal and snack patterns of school children vary considerably with age and sex.

Adolescent↗

Coffee consumption and risk of rheumatoid arthritis.

OBJECTIVE: Recent reports have suggested an association between consumption of coffee or decaffeinated coffee and the risk of rheumatoid arthritis (RA), although data are sparse and somewhat inconsistent. Furthermore, existing studies measured dietary exposures and potential confounders only at baseline and did not consider possible changes in diet or lifestyle over the followup period. We studied whether coffee, decaffeinated coffee, total coffee, tea, or overall caffeine consumption was associated with the risk of RA, using the Nurses' Health Study, a longitudinal cohort study of 121,701 women. METHODS: Information on beverage consumption was assessed with a food frequency questionnaire (FFQ) that was completed every 4 years, from baseline in 1980 through 1998. Among the 83,124 women who completed the FFQ at baseline, the diagnosis of incident RA (between 1980 and 2000) was confirmed in 480 women by a connective tissue disease screening questionnaire and medical record review for American College of Rheumatology criteria. Relationships between intake of various beverages and the risk of RA were assessed in age-adjusted models and in multivariate Cox proportional hazards models including the cumulative average intake of each beverage during the followup period, adjusted for numerous potential confounders. In addition, for direct comparisons with prior reports, multivariate analyses were repeated using only baseline beverage information. RESULTS: We did not find a significant association between decaffeinated coffee consumption of >/=4 cups/day (compared with no decaffeinated coffee consumption) and subsequent risk of incident RA, in either an adjusted multivariate model (relative risk [RR] 1.1, 95% confidence interval [95% CI] 0.5-2.2) or a multivariate model using only baseline reports of decaffeinated coffee consumption (RR 1.0, 95% CI 0.6-1.7). Similarly, there was no relationship between cumulative caffeinated coffee consumption and RA risk (RR 1.1, 95% CI 0.8-1.6 for >/=4 cups per day versus none) or between tea consumption and RA risk (RR 1.1, 95% CI 0.7-1.8 for >3 cups/day versus none). Total coffee and total caffeine consumption were also not associated with the risk of RA. CONCLUSION: In this large, prospective study, we find little evidence of an association between coffee, decaffeinated coffee, or tea consumption and the risk of RA among women.

Adult↗

Coffee and tea consumption and cancers of the bladder, colon and rectum.

Coffee has been observed to be associated weakly or not at all with bladder cancer risk, inversely with colon cancer risk, and inconsistently with rectal cancer risk. The association between these cancers and consumption of coffee and tea was examined in a single case-control study conducted in Ontario, Canada from 1992 to 1994. A questionnaire was filled out by 927 bladder cancer cases, 991 colon cancer cases, 875 rectal cancer cases, and 2118 population controls. Although bladder cancer risk was not associated with coffee or tea, risk estimates associated with coffee among subjects who had never smoked were non-significantly increased. Colon cancer risk was inversely associated with coffee. Relative to those drinking less than 1 cup of coffee per day, the odds ratios (OR) for those drinking 1-2 cups was 0.9 (95% CI 0.8-1.1), for those drinking 3-4 cups was 0.8 (95% CI 0.7-1.0), and for those drinking 5 or more cups was 0.7 (95% CI 0.5-0.9); these ORs decreased linearly (P = 0.008). The reduced risk estimates were more pronounced with cancer of the proximal colon than the distal colon. Rectal cancer risk was not associated with either coffee or tea. Coffee consumption was observed to have a different relationship for each of the cancer sites and tea consumption was not related to any cancer site.

Case-Control Studies↗

The role of alcohol in the anti low density lipoprotein oxidation activity of red wine.

Oxidation of low density lipoprotein cholesterol (LDL-c) is supposed to play a role in the generation of atherosclerotic lesions. Grape derived beverages supply a large number of nutritional antioxidants because of their high content of polyphenols. This might be one of the mechanisms behind the supposed beneficial effect of red wine. Wine also contains alcohol and its role in oxidation processes especially in vivo is unclear. In this study the effect of daily red wine consumption for 2 weeks on oxidizability status of LDL was investigated. The role of alcohol in LDL oxidation was further explored in in vitro experiments. After abstinence from alcoholic beverages, grape juices and tea for a week, seven healthy male volunteers consumed 375 ml of red wine (30 g alcohol) per day during 2 weeks. At the start and end of the drinking period blood samples were taken and the susceptibility of LDL-c to copper-induced oxidation was analyzed with the addition of distilled water (control) and dilutions of a 12% alcohol solution, white wine and red wine. Although red wine at concentrations achievable in vivo caused a significant prolongation of the lag-time of metal ion dependent LDL oxidation in vitro (85.9+/-23.0-114.1+/-30.8 min, P<0. 001), a significant shortening of lag-time was found in vivo after the 2 weeks of wine consumption (56.3+/-13.0 min, P<0.001). A shorter lag-time compared to the control was found for both alcohol and white wine in vitro. The changed oxidizability status of LDL after 2 weeks of wine consumption made it more susceptible for the in vitro antioxidant effect of red wine. At low dilutions red grape juice extended lag-time as well, which was not influenced by the addition of alcohol. Red wine has a strong inhibitory effect on copper-induced oxidation of LDL in vitro, while red grape juice has a minor effect, an effect which should be attributed to the non alcohol components in the beverages. In vivo, however, this effect can be overshadowed by the prooxidant influence of alcohol. The balance between alcohol and polyphenols of a wine may be critical for its in vivo effect on LDL oxidation.

Adult↗

Associations between black tea and coffee consumption and risk of lung cancer among current and former smokers.

Although cigarette smoking is a clear risk factor for lung cancer, the other determinants of lung cancer risk among smokers are less clear. Tea and coffee contain catechins and flavonoids, which have been shown to exhibit anticarcinogenic properties. Conversely, caffeine may elevate cancer risk through a variety of mechanisms. The current study investigated the effects of regular consumption of black tea and coffee on lung cancer risk among 993 current and former smokers with primary incident lung cancer and 986 age-, sex-, and smoking-matched hospital controls with non-neoplastic conditions. Results indicated that lung cancer risk was not different for those with the highest black tea consumption (>or=2 cups/day) compared with nondrinkers of tea [adjusted odds ratio (aOR)=0.90; 95% confidence interval (CI)=0.66-1.24]. However, elevated lung cancer risk was observed for participants who consumed 2-3 cups of regular coffee daily (aOR=1.34; 95% CI=0.99-1.82) or >or=4 cups of regular coffee daily (aOR=1.51, 95% CI=1.11-2.05). In contrast, decaffeinated coffee drinking was associated with decreased lung cancer risk for both participants who consumed or=2 cups/day (aOR=0.64; 95% CI=0.51-0.80). These results suggest that any chemoprotective effects of phytochemicals in coffee and tea may be overshadowed by the elevated risk associated with caffeine in these beverages.

Adult↗

Chinese tea consumption and lower risk of Helicobacter infection.

BACKGROUND: Our first study had shown that Chinese tea has anti-Helicobacter activity. The present study investigated the relationship between patients'Helicobacter status and the history of Chinese tea consumption. METHODS: Chinese patients who had their first upper endoscopy were recruited. Before the procedure, patients completed questionnaires about their current Chinese tea consumption habits and those when they were around 10-25 years old. This information was used to calculate the tea consumption indices (TCI). Gastric biopsies (two from the antrum and two from the corpus) were taken for histological examination for Helicobacter. RESULTS: Eighty patients were recruited. Eight patients were rejected because of either an incomplete questionnaire, absence of gastric biopsy or a suspected history of treatment for Helicobacter infection. Of the 72 patients, 42 (58.3%) were Helicobacter positive. The age, sex ratio and indications for endoscopy were similar in both Helicobacter-positive and -negative groups. Classifying patients using either current, past or total TCI, patients with high tea consumption had significantly lower Helicobacter infection rate than those with low tea consumption (45% compared to 74%, 42% compared to 67% and 40% compared to 83%, respectively). Helicobacter-negative patients had higher overall TCI than Helicobacter-positive patients (28.2:17.3). When current and previous histories were analyzed separately, Helicobacter-negative patients also had a trend towards higher TCI currently (16.6:11.0) and in their 20s (11.6:6.1). CONCLUSIONS: There is a significant inverse relationship between Chinese tea consumption and Helicobacter infection. Chinese tea consumption may decrease the chance of Helicobacter infection.

Adult↗

Tobacco and alcohol use among the youth of the agricultural tea industry in Assam, India.

A cross-sectional study was conducted to assess tobacco use (both smoking and non-smoked tobacco) and alcohol use among tea garden youths of Assam, India during the period 2002-2003. A total of 650 tea plantation youth age 15-24 years (255 males, 395 females) from eight randomly selected tea plantations, Dibrugarh District, Assam, were interviewed to collect information on alcohol and tobacco use using a pre-designed, pre-tested questionnaire. Nearly 59% of the respondents had no formal education. Fifty-eight percent of the youth used at least one substance and 27.4% were concurrent users of both alcohol and tobacco. The smoking rate was only 2.2% (4.7% in males, 0.5% in females). However, 52.5% of the study population used non-smoked tobacco (56.9% males, 49.6% females). The prevalence of alcohol consumption was 32.2% (43.9% males, 24.6% females). A higher rate of alcohol and tobacco use was found among the respondents who had no formal education or were school dropouts. A higher rate of alcohol and tobacco use were seen among respondents in whom both parents were illiterate. Working as a manual worker in the tea industry is significantly associated (p<0.01) with higher rates of alcohol and tobacco use. We recommend a vigorous campaign against tobacco and alcohol use among tea plantation youth to reduce the health risks associated with the use of these two substances.

Adolescent↗

Effect of black tea intake on the excretion of mutagens in the urine of volunteers taking a beef meal.

The objective of this study was to investigate in a crossover study conducted in human volunteers whether black tea intake modulates the metabolism of heterocyclic amines, consumed in the form of well-cooked beefburgers, as exemplified by the excretion of mutagens in the urine. Mutagens were extracted from urine with blue rayon, and mutagenic activity was determined in the Ames test, in the presence of an activation system derived from Aroclor 1254-induced rats, and employing the Salmonella typhimurium O-acetylase over-expressing YG1024 bacterial strain. Volunteers consumed three well-cooked beefburgers, whereas a concurrently cooked fourth burger was analyzed for mutagenic activity. Following intake of the burgers, an increase in urinary mutagenic activity was observed, and mutagenic activity was completely excreted within 24 hours. A good correlation was obtained between the intake and excretion of mutagenic activity. The volunteers consumed the same burger meal on two different occasions, once following intake of 10 cups of strong black tea, and the second following intake of a corresponding volume of water. Urine was collected by each volunteer for 24 hours after the meal, and compliance was ascertained utilizing the excretion of p-aminobenzoic acid. The mutagenic ratio, defined as the ratio of urinary mutagenicity over the intake of mutagenicity, was not altered by the black tea, being 0.142 and 0.135 during the water and tea intake, respectively. It is inferred that short-term intake of high levels of black tea, as part of an otherwise normal diet, does not modulate the human metabolism of heterocyclic amines.

Adult↗