Cumulative tea consumption is inversely associated with colorectal adenomas in adults: A cross-sectional study in a Taiwanese population.

PURPOSE: This study examined the association between cumulative tea consumption over time and various colorectal adenomas as well as their pathology, number, and size. METHODS: 7355 eligible subjects who underwent health check-ups with colonoscopies were recruited. They were classified into three groups: polyp-free, having low-risk colorectal adenomas, and having high-risk colorectal adenomas. The adenoma pathology, number, and size were collected. We defined 120 mL for each Chinese traditional teapot as a 'cup', and calculated the average daily cups of tea consumed. A 'cup-year' was defined as the daily cups multiplied by the years of tea consumption and was used to express the cumulative amount of tea consumption over time. RESULTS: Compared to those with no habitual tea consumption, the lowest, middle, and highest tertiles of tea consumption were found to be inversely related to low-risk colorectal adenomas. For high-risk colorectal adenomas, a negative association was found only in the group with the highest tertile of tea consumption. An inverse association between the highest tertile of tea consumption and various features of high-risk colorectal adenomas was also found for villous-rich adenomas and the presence of three or more adenomas, but was not found to be related to adenoma size ≥1 cm. CONCLUSION: Tea drinking was inversely associated with both low-risk and high-risk colorectal adenomas. Only a larger cumulative dose of ≥42 cup-years was negatively associated with high-risk colorectal adenomas, especially adenomas with villous-rich pathology and when three or more adenomas were present.

Increased amount and duration of tea consumption may be associated with decreased risk of renal stone disease.

PURPOSE: Previous studies have looked into the association between tea consumption and renal stone disease, but the impact of tea consumption over time has not yet been fully clarified. Our study aimed to examine the amount and duration of tea consumption concomitantly in relation to the risk of renal stone disease. METHODS: A total of 13,842 subjects who underwent health check-ups were recruited. Average tea consumption per day was defined as the amount of tea consumption per day multiplied by the frequency per week divided by seven. A "cup" was defined as 120 mL for each Chinese traditional teapot," and "cup-year" was calculated by multiplying the number of daily cups and the years of tea consumption to express the cumulative dose of tea consumption over time. The diagnosis of renal stone disease was established based on the results of abdominal sonography. RESULTS: The amount of daily tea consumption was 119.2 ± 306.8 and 131.7 ± 347.3 mL in groups with and without renal stone disease. After adjusting for other clinical variables, daily tea consumption ≥ 240 mL vs. none was related to lower risk of renal stone disease (OR = 0.84, CI 0.71-0.99, p = 0.037). In another model, the associated risk of renal stone disease decreased significantly with tea consumption ≥ 20 cup-year (OR = 0.79, CI 0.66-0.94, p = 0.008), but not < 20 cup-year (OR = 0.92, CI 0.78-1.09, p = 0.34). CONCLUSIONS: Daily tea consumption ≥ 240 mL (two cups) was associated with a lower risk of renal stone disease. Tea consumption ≥ 20 cup-year also had a decreased associated risk of renal stone disease.

Moderate, but not heavy, tea drinking decreased the associated risk of gallstones in a Taiwanese population.

BACKGROUND/OBJECTIVES: The aim of the present study was to investigate the relationship between tea drinking and gallstones, specifically to evaluate the amount and time of tea consumption by gender. SUBJECTS/METHODS: A total of 14,555 eligible adults receiving health examinations were included. The participants were divided into three subgroups with tea consumption of none, <240/day and ≥240 ml/day. We defined 120 ml for each traditional Chinese teapot as a "cup," and the variable "cup-year" was obtained by multiplying the cups per day by the years of tea consumption. Based on the findings of abdominal ultrasound examination, gallstones was defined by the presence of movable or gravity-dependent intraluminal hyperechoic foci that attenuated ultrasound transmission. RESULTS: Among the participants, 1040 (7.1%) had gallstones. In multivariate analysis, the inverse relationship between tea drinking habit and gallstones was significant (OR = 0.807; 95% CI = 0.685-0.951, p = 0.010). Daily consumption of 1-240 ml (OR = 0.741; 95% CI = 0.584-0.941, p = 0.014), but not ≥240 ml, was associated with reduced risk of gallstones. In addition, the 1-19 cup-year group had significantly lower associated risk of gallstones (OR = 0.677; 95% CI = 0.534-0.857, p = 0.001), while the ≥19 cup-year group did not. By gender, subjects with tea consumption of 1-19 cup-year exhibited a low associated risk of gallstones in both males (OR = 0.678; 95% CI = 0.504-0.913, p = 0.010) and females (OR = 0.671; 95% CI = 0.453-0.994, p = 0.047), while subjects with ≥19 cup-years did not. CONCLUSIONS: Appropriate tea drinking if less than 240 ml/day or 19 cup-years was associated with a decreased risk of gallstones in both genders.

In vivo and in vitro anti-tumor effects of fungal extracts.

Fungal extracts are extensively used as nutritional supplements in Far-Eastern Asia. In this study, we aimed to evaluate the anti-cancer activities of some different fungal species against different cancer cell lines. The water or ethanol extracts of Fomitopsis pinicola (F. pinicola), Ganoderma sinense, Fomitopsis officinalis, Polyporus melanopus, and Taiwanofungus camphorates were used to evaluate the anti-cancer activities in various cancer cells. We found that all of the fungi ethanol extracts used in this study exert anti-cancer activities in vitro, whereas water extracts show lower inhibitory activities as determined by 3-(4,5-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. Among the tested fungi species, F. pinicola ethanol extract exerts the most significant anti-cancer activity (growth inhibitory ratio 82.8%, p < 0.001) by increasing cell apoptosis. Moreover, F. pinicola ethanol extract significantly decreased tumor size (tumor growth inhibitory ratio 54%, p < 0.05) and increased the lifespan in mice bearing sarcoma-180 tumors. Taken together, this is the first study indicating the anti-tumor effect of F. pinicola in vivo and in vitro. F. pinicola ethanol extract induces cell apoptosis to exert a significant anti-tumor activity, with potential to be a new alternative anti-tumor medicine.

Increased tea consumption is associated with decreased arterial stiffness in a Chinese population.

BACKGROUND: Tea has attracted considerable attention for its potential cardioprotective effects. The primary chemical components of tea are thought to have a beneficial effect by reducing arterial stiffness. The objective of this study was to assess the association between tea consumption and brachial-ankle pulse wave velocity (baPWV) in a relatively healthy Chinese population. METHODS: We enrolled 3,135 apparently healthy subjects from October 2006 to August 2009. Subjects taking medication for diabetes, hypertension, or hyperlipidemia, or with a history of cardiovascular disease, were excluded from the study. The subjects were categorized into three groups according to their tea-drinking habits: (1) none to low (n = 1615), defined as non-habitual tea drinkers, or drinking for <1 year, or drinking ≤150 mL per day for ≥1 year ; (2) moderate tea consumption, defined as drinking for ≥1 year and consumption between 151 and 450 mL per day; and (3) heavy tea consumption, defined as a drinking for ≥1 year and consumption >450 mL per day. Multiple logistic regression was used to determine whether different levels of consumption were independently associated with the highest quartile of baPWV values, defined as ≥1428.5 cm/s. RESULTS: Of the 3,135 subjects, 48.5% had drunk >150 mL of tea per day for at least 1 year. In multivariate regression analysis with adjustment for co-variables, including, age, sex, current smoking, alcohol use, habitual exercise, total cholesterol/high-density lipoprotein cholesterol (TC/HDL-C) ratio >5, obesity, newly diagnosed hypertension and diabetes, subjects with high tea consumption had a decreased risk of highest quartile of baPWV by 22% (odds ratio = 0.78, 95% confidence interval = 0.62-0.98, p = 0.032), while subjects with moderate tea consumption did not (p = 0.742), as compared subjects with none to low tea consumption. CONCLUSIONS: High, but not moderate, habitual tea consumption may decrease arterial stiffness.

The protective effect of habitual tea consumption on hypertension.

BACKGROUND: Tea has long been believed to possess hypotensive effects in popular Chinese medicine. However, conflicting results have been shown among human trials and animal studies on the relation between tea consumption and blood pressure. Epidemiological evidence about the long-term effect of tea on hypertensive risk is also inconsistent. METHODS: We examined the effect of tea drinking, measured in detail for the past decades, on the risk of newly diagnosed hypertension in 1507 subjects (711 men and 796 women), 20 years or older, who did not have a hypertensive history during 1996 in Taiwan. RESULTS: Six hundred subjects (39.8%) were habitual tea drinkers, defined by tea consumption of 120 mL/d or more for at least 1 year. Compared with nonhabitual tea drinkers, the risk of developing hypertension decreased by 46% for those who drank 120 to 599 mL/d and was further reduced by 65% for those who drank 600 mL/d or more after carefully adjusting for age, sex, socioeconomic status, family history of hypertension, body mass index, waist-hip ratio, lifestyle factors (total physical activity, high sodium intake, cigarette smoking, alcohol consumption, and coffee drinking), and dietary factors (vegetable, fruit, unrefined grain, fish, milk, visible-fat food, and deep fried food intake). However, tea consumption for more than 1 year was not associated with a further reduction of hypertension risk. CONCLUSION: Habitual moderate strength green or oolong tea consumption, 120 mL/d or more for 1 year, significantly reduces the risk of developing hypertension in the Chinese population.

Relationship among habitual tea consumption, percent body fat, and body fat distribution.

OBJECTIVE: To disclose the possible relationship between habitual tea consumption and changes in total body fat and fat distribution in humans. RESEARCH METHODS AND PROCEDURES: A cross-sectional survey of 1,210 epidemiologically sampled adults (569 men and 641 women) were enrolled in our study. Tea consumption and other lifestyle characteristics were obtained by structured questionnaires. Percent body fat (BF%) was measured using bioelectrical impedance analysis. Body fat distribution was assessed using waist-to-hip ratio (WHR). RESULTS: Among the 1,103 analyzed subjects, 473 adults (42.9%) consumed tea once or more per week for at least 6 months. The habitual tea drinkers were male-dominant, more frequently current smokers, and alcohol or coffee drinkers than the nonhabitual tea drinkers. Habitual tea drinkers for more than 10 years showed a 19.6% reduction in BF% and a 2.1% reduction in WHR compared with nonhabitual tea drinkers. The multiple stepwise regression models revealed that men, older age, higher BMI, and current smokers were positive factors for BF% and WHR. In contrast, longer duration of habitual tea consumption and higher total physical activity were negative factors for BF%. Longer duration of habitual tea consumption, higher socioeconomic status, and premenopausal status were negative factors for WHR. DISCUSSION: An inverse relationship may exist among habitual tea consumption, BF%, and body fat distribution, especially for subjects who have maintained the habit of tea consumption for more than 10 years.

Epidemiological evidence of increased bone mineral density in habitual tea drinkers.

BACKGROUND: Researchers have hypothesized that bone mineral density (BMD) may be influenced by chemical compounds such as caffeine, phytoestrogen, fluoride, and many compounds that are contained in tea extracts. Hence, the relationship between habitual tea consumption and BMD is an interesting issue. METHODS: Based on an epidemiological survey, we enrolled 497 men and 540 women, 30 years and older, in our study. All subjects were questioned about their habit of tea consumption and other lifestyle characteristics by means of a structured questionnaire. Dual-energy x-ray absorptiometry was used to measure the BMD of the total body, lumbar spine (L1-L4), hip neck, and Ward triangle regions. RESULTS: Five hundred two subjects (48.4%) were habitual tea drinkers, with a mean duration of tea consumption of approximately 10 years. Compared with nonhabitual tea drinkers, subjects with habitual tea consumption of 6 to 10 years showed higher lumbar spine BMDs, and those with consumption of more than 10 years showed the highest BMDs of all measured regions. Under the multiple stepwise regression models, sex, age, body mass index, total physical activity, and habit of tea consumption were the major significant variables for the different BMD regions. Regarding the behavioral characteristics of tea consumption, the duration of tea consumption was the only independent determinant for the BMDs. CONCLUSION: Habitual tea consumption, especially for more than 10 years, has significant beneficial effects on BMD of the total body, lumbar spine, and hip regions in adults.