Tea flavonoids and cardiovascular disease

School of Medicine and Pharmacology, GPO Box X2213, Perth, WA, 6847, Australia.
Asia Pacific Journal of Clinical Nutrition (Impact Factor: 1.7). 02/2008; 17 Suppl 1:288-90.
Source: PubMed


Drinking tea could have a significant impact on public health. Health benefits are believed to be largely due to the presence of high levels of flavonoids. Tea is a rich source of flavonoids, and often the major dietary source. Tea intake and intake of flavonoids found in tea have been associated with reduced risk of cardiovascular disease in cross-sectional and prospective population studies. In addition, flavonoids have consistently been shown to inhibit the development of atherosclerosis in animal models. A variety of possible pathways and mechanisms have been investigated. The focus of this review is on the potential of tea and tea flavonoids to improve endothelial function, and reduce blood pressure, oxidative damage, blood cholesterol concentrations, inflammation and risk of thrombosis. There is now consistent data to suggest that tea and tea flavonoids can improve endothelial function. This may be at least partly responsible for any benefits on risk of cardiovascular disease. Additional studies are needed to investigate whether regular consumption of tea can reduce blood pressure, inflammation and the risk of thrombosis. The evidence for benefit on oxidative damage and cholesterol reduction remains weak.

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    • "and Paullinia cupana (Delle Monache et al., 1972; Yamaguti-Sasaki et al., 2007). (+)-Catechin, (2)-E, and their derivatives such as (2)-ECG are the major flavan-3-ols reported from tea (Tijburg et al., 1997; Henning et al., 2003; Hodgson, 2008). To the best of our knowledge, neither (2)-catechin nor (+)-E have been described from the tea plant itself, as is the case in grape, where the in vitro products of ANR appear to be the enantiomers of the most abundant in vivo metabolites (Gargouri et al., 2009). "
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    ABSTRACT: Tea (Camellia sinensis) is rich in specialized metabolites, especially polyphenolic proanthocyanidins (PAs) and their precursors. To better understand the PA pathway in tea, we generated a cDNA library from leaf tissue of the blister blight-resistant tea cultivar TRI2043, and functionally characterized key enzymes responsible for the biosynthesis of PA precursors. Structural genes encoding enzymes involved in the general phenylpropanoid/flavonoid pathway and the PA-specific branch pathway were well represented in the library. Recombinant tea leucoanthocyanidin reductase (CsLAR) expressed in E. coli was active with leucocyanidin as substrate to produce the 2R,3S-trans-flavan-ol (+)-catechin in vitro. Two genes encoding anthocyanidin reductase, CsANR1 and CsANR2, were also expressed in E. coli, and the recombinant proteins exhibited similar kinetic properties. Both converted cyanidin to a mixture of (+)-epicatechin and (-)-catechin, although in different proportions, indicating that both enzymes possess epimerase activity. These epimers were unexpected based on the belief that tea PAs are made from (-)-epicatechin and (+)-catechin. Ectopic expression of CsANR2 or CsLAR led to accumulation of low levels of PA precursors and their conjugates in Medicago truncatula hairy roots and anthocyanin over-producing tobacco, but levels of oligomeric PAs were very low. Surprisingly, expression of CsLAR in tobacco over-producing anthocyanin led to accumulation of higher levels of epicatechin and its glucoside than of catechin, again highlighting the potential importance of epimerization in flavan-3-ol biosynthesis. The present data provide a resource for understanding tea PA biosynthesis, and tools for the bioengineering of flavanols.
    Full-text · Article · Jan 2013 · Plant physiology
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    • "Tea is a widely consumed beverage and has been studied extensively for its possible health effects. A number of studies have found tea consumption to be associated with lower risks of coronary heart disease (Hodgson, 2008; Ruxton, 2008; Tijburg et al., 1997), certain cancers (Blot et al., 1996; Kohlmeier et al., 1997; Ruxton, 2008), stroke (Larsson et al., 2008; Arab et al., 2009; Hollman et al., 2010), bone loss (Gardner et al., 2006; Devine et al., 2007), and dental caries (Ruxton, 2008). It is believed that catechin, an antioxidant found in tea, may be responsible for some of these health benefits (Navarro-Perán et al., 2005; Alemdaroglu et al., 2007). "
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    ABSTRACT: Studies have demonstrated that catechin, an antioxidant found in tea, can reduce the bioavailability of folate. Because periconceptional folic acid intake has been demonstrated to reduce the risk of spina bifida, tea consumption may put pregnant women at risk because of its possible antifolate properties. Using data collected in the Slone Epidemiology Center Birth Defects Study, we examined whether tea consumption during early pregnancy was associated with an increased risk of spina bifida. Mothers of 518 spina bifida cases and 6424 controls were interviewed within 6 months after delivery about pregnancy events and exposures. Data on tea intake were collected during three periods (1976-1988, 1998-2005 and 2009-2010). Logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for study center. Intake of both periconceptional food folate and diet and supplemental folic acid were examined as a potential effect modifier. For 1976 to 1988, ORs were not elevated for daily tea intake. For 1998 and onward, ORs were also close to 1.0, but there was a modest increase for those who drank more than 3 cups/day (OR, 1.92; 95% CI, 0.84-4.38). Among women with total folic acid intake greater than 400 μg, consumption of 3 cups or more of tea per day was associated with an increased risk of spina bifida in 1976 to 1988 (OR, 2.04; 95% CI, 0.69-7.66) and in the later periods (OR, 3.13; 95% CI, 0.87-11.33). Our data do not support an overall association between tea consumption and spina bifida, but there is a suggestion of a possible interaction between higher levels of folic acid intake and tea consumption. Birth Defects Research (Part A) 2012. © 2012 Wiley Periodicals, Inc.
    Full-text · Article · Oct 2012 · Birth Defects Research Part A Clinical and Molecular Teratology
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    • "Using animal models of atherosclerosis Grassi and others (2008) has indicated that dietary flavonoid consumption delays atherosclerotic plaque development and may reduce endothelial dysfunction, which is the key step in the development of atherosclerosis. Hodgson (2008) reported that flavonoids inhibit the development of atherosclerosis in animal models. Choi and others (2008) suggested that (-)epigallocatechin gallate and hesperetin, both flavonoids, may act as antiatherogenic agents by blocking oxidized LDL-induced endothelial apoptosis via differential cellular apoptotic mechanisms. "
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    ABSTRACT: Worldwide, cardiovascular disease is estimated to be the leading cause of death and loss of disability-adjusted life-years. Effective prevention needs a global strategy based on knowledge of the importance of risk factors, including diet. Recent years have seen increased interest on the part of consumers, researchers, and the food industry into how food products can help maintain the health of an individual. Extracts rich in dietary fiber obtained from plants could be used as functional ingredients because they provide numerous health benefits that go far beyond supporting bowel regularity. These benefits may include not only digestive health, but weight management, cardiovascular health, and general wellness. The objective of this review is to present an overview of the potential of different types of fiber as a technological tool for its application to functional foods to reduce the incidence of cardiovascular disease through diet.
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