Green tea: Potential health benefits

Department of Family Medicine, Maine Medical Center, Portland, Maine 04102, USA.
American family physician (Impact Factor: 2.18). 05/2009; 79(7):591-4.
Source: PubMed


Green tea has been used widely and in high doses for centuries as a health tonic in many societies. Evidence suggests that green tea is effective for treating genital warts. There is some supportive evidence for the use of green tea in cancer prevention. Drinking green tea is associated with a decrease in all-cause mortality, but not in cancer-related mortality. Small clinical studies have found that green tea may also be helpful in losing and managing weight, and lowering cholesterol. Epidemiologic evidence suggests that green tea may prevent stroke and cardiovascular disease. Green tea appears to be safe, although there have been case reports of hepatotoxicity possibly related to a specific extract in pill or beverage form. Green tea seems to be a low-risk complementary therapy for a number of conditions, but more studies are needed.

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    • "First, green tea is processed from a plant called Camellia sinensis, which contains antioxidant polyphenols. Green tea has the highest concentration of (-) epigallocatechin gallate, the most active polyphenol catechin, among all kinds of tea [2]. Tea catechins possess many beneficial properties, including regulation of blood pressure, body fat [21] and lipids [22], and improvement of glycemic control [23]. "
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    ABSTRACT: Background and Purpose: We examined the association between green tea consumption and mortality due to all causes, cancer, heart disease, cerebrovascular disease, respiratory disease, injuries and other causes of death in a large-scale population-based cohort study in Japan. Methods We studied 90,914 Japanese (aged between 40 and 69 years) recruited between 1990 and 1994. After 18.7 years of follow-up, 12,874 deaths were reported. The association between green tea consumption and risk of all causes and major causes of mortality was assessed using the Cox proportional hazards regression model with adjustment for potential confounders. Results Hazard ratios for all-cause mortality among men who consumed green tea compared with those who drank less than 1 cup per day were 0.96 (0.89 to 1.03) for 1 to 2 cups per day, 0.88 (0.82 to 0.95) for 3 to 4 cups per day, and 0.87 (0.81 to 0.94) for more than 5 cups per day (p for trend <0.001). Corresponding hazard ratios for women were 0.90 (0.81 to 1.00), 0.87 (0.79 to 0.96), and 0.83 (0.75 to 0.91) (p for trend <0.001). Green tea was inversely associated with mortality from heart disease in both men and women, and mortality from cerebrovascular disease and respiratory disease in men. No association was found between green tea and total cancer mortality. Conclusion This prospective study suggests that the consumption of green tea may reduce the risk of all-cause mortality and the three leading causes of death in Japan.
    Annals of Epidemiology 03/2015; 25(7). DOI:10.1016/j.annepidem.2015.03.007 · 2.00 Impact Factor
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    • "Green tea, a polyphenol-rich beverage has drawn much attention due to its health benefits in cardiovascular disease, diabetes, inflammatory diseases, and its prevention and treatment of cancer [21]. Green tea is rich in flavonoids and contains many catechins, including (-)- epigallocatechin-3-gallate (EGCG), which is the most abundant (~60%) catechin in green tea [22]. "
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    ABSTRACT: Aging is associated with impaired learning and memory accompanied by reductions in adult hippocampal neurogenesis and brain expression of neurotrophic factors among other processes. Epigallocatechin-3-gallate (EGCG, a green tea catechin), β-alanine (β-ala, the precursor of carnosine), and exercise have independently been shown to be neuroprotective and to reduce inflammation and oxidative stress in the central nervous system. We hypothesized that EGCG, β-ala supplementation or exercise alone would improve learning and memory and increase neurogenesis in aged mice, and the combined intervention would be better than either treatment alone. Male Balb/cByJ mice (19 mo) were given AIN-93M diet with or without EGCG (182mg/kg/d) and β-ala (417mg/kg/d). Half of the mice were given access to a running wheel (VWR). The first 10 days, animals received 50mg/kg bromodeoxyuridine (BrdU) daily. After 28 days, learning and memory was assessed by Morris water maze (MWM) and contextual fear conditioning (CFC). Brains were collected for immunohistochemical detection of BrdU and quantitative mRNA expression in the hippocampus. VWR increased the number of BrdU cells in the dentate gyrus, increased expression of brain-derived neurotrophic factor, decreased expression of the inflammatory cytokine interleukin-1β, and improved performance in the MWM and CFC tests. The dietary intervention reduced brain oxidative stress as measured by 4-hydroxynonenal in the cerebellum, but had no effect on BrdU labeling or behavioral performance. These results suggest that exercise, but not a diet containing EGCG and β-ala, exhibit pro-cognitive effects in aged mice when given at these doses in this relatively short time frame.
    Behavioural Brain Research 07/2014; 272. DOI:10.1016/j.bbr.2014.05.049 · 3.03 Impact Factor
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    • "). Recently, green tea has attracted attention due to its excellent performances in consumer health and even in weight management (Schneider and Segre 2009). Tea plant (Camellia sinensis (L.) O. Kuntze) is an evergreen perennial whose vegetative buds stop growing and develop dormancy in fall as a defence against chilling stress during winter in temperate regions. "
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    ABSTRACT: Tea plant (Camellia sinensis (L.) O. Kuntze) is an important cash crop. In temperate regions, bud dormancy in winter and budbreak in spring are important biological phenomena for the tea plant life cycle. To understand the molecular mechanism of dormancy maintenance and release in tea plant, the differentially expressed genes in dormant and sprouting axillary buds were investigated in two cultivars (special early-sprouting tea cultivar ‘Camellia sinensis cv. Longjing 43’ (‘LJ’) and late-sprouting tea cultivar ‘C. sinensis cv. Zhenghe Dabaicha’ (‘ZD’)), using suppression subtractive hybridization (SSH) approach. Four high performance complementary DNA (cDNA)-SSH libraries (‘LJ’ sprouting bud library, ‘LJ’ dormant bud library, ‘ZD’ sprouting bud library and ‘ZD’ dormant bud library) were constructed, and 1,736 valid ESTs were obtained, in which 1,242 ESTs were unique to the sprouting bud libraries and 494 ESTs were unique to the dormant bud libraries. Based on sequence matching and gene ontology analysis, 1,287 unigenes consisting of 208 contigs and 1,079 singletons were identified, in which 995 had Blast hits. The putative functions of differentially regulated sequences were involved in most aspects of plant biological processes. The quality and expression patterns of partial ESTs from these four libraries were validated by qRT-PCR. We identified numerous differentially expressed genes mainly involved in stress response, water metabolism, cell division regulation, energy metabolism and hormone regulation from dormant and sprouting bud libraries. This study provides general information on tea plant axillary bud dormancy and release at the transcriptional level and provides some hypotheses for further exploration on the mechanism of bud dormancy and budbreak in tea plant.
    Tree Genetics & Genomes 06/2014; 10(5). DOI:10.1007/s11295-014-0749-6 · 2.45 Impact Factor
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