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: 1.36). 02/2008; 17 Suppl 1:288-90.
Source: PubMed

ABSTRACT 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.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: There is increasing evidence that tea and its non-caffeine components (primarily flavonoids) contribute to cardiovascular health. Randomized controlled trials have shown that tea can improve cardiovascular disease risk factors. We have previously reported a non-caffeine associated beneficial effect of regular black tea consumption on blood pressure and its variation. Objective: To explore the non-caffeine associated effects of black tea on body weight and body fat distribution, and cardiovascular disease related metabolic outcomes. Design: regular tea-drinking men and women (n = 111; BMI 20-35 kg m(-2)) were recruited to a randomized controlled double-blind 6 month parallel-designed trial. Participants consumed 3 cups per day of either powdered black tea solids (tea) or a flavonoid-free flavour- and caffeine-matched placebo (control). Body weight, waist- and hip-circumference, endothelial function and plasma biomarkers were assessed at baseline, 3 months and 6 months. Results: Compared to control, regular ingestion of black tea over 3 months inhibited weight gain (-0.64 kg, p = 0.047) and reduced waist circumference (-1.88 cm, P = 0.035) and waist-to-hip ratio (-0.03, P = 0.005). These effects were no longer significant at 6 months. There were no significant effects observed on fasting glucose, insulin, plasma lipids or endothelial function. Conclusion: Our study suggests that short-term regular ingestion of black tea over 3 months can improve body weight and body fat distribution, compared to a caffeine-matched control beverage. However, there was no evidence that these effects were sustained beyond 3 months.
    Food & Function 06/2014; · 2.91 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Many epidemiological studies have shown the benefits of a diet rich in fruit and vegetables to human health and for the prevention of various diseases associated with oxidative stress, such as cancer and cardiovascular diseases. Anthocyanins, natural pigments belonging to the group of flavonoids, are common components of the human diet, as they are present in many foods, fruits, and vegetables, especially in berries. Their use as colorants has considerable interest because of their coloring properties. Moreover, they have an antioxidant activity. Various adverse effects on health have frequently been attributed to synthetic antioxidants. For these reasons, currently, there is a trend towards relying on antioxidants derived from natural products. The efficacy of anthocyanins as antioxidants depends, to a large extent, upon their chemical structure. They act as antioxidants both in the foodstuffs in which they are found and in the organism after intake of these foods. With this in mind, an introduction to polyphenols is made with emphasis on their role as secondary metabolites, classification, and health relevance. Flavonoid intake, biological activities, databases, classification and structure, distribution, and dietary sources are then considered. Aspects of anthocyanin concerning its early history and chemical structure, color, and intake are dealt with in the second part of the series. The extraction and analysis of anthocyanin pigments and their antioxidant power, paying special attention to the oxidation process, will be the subject of the third part. Bioavailability and metabolism of anthocyanic pigments, the methods used for measuring the antioxidant activity of anthocyanins, and the influence of anthocyanins on the antioxidant activity of wine will finally be covered in the fourth part. The present review intends to reflect the interdisciplinary nature of the research that is currently carried out in this prolific area. Key research articles and reviews are mainly referenced, and we apologize to those researchers whose work is not cited directly by us.
    Critical Reviews in Analytical Chemistry 04/2012; 42(2):102-125. · 2.69 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Thanks to its polyphenols and phytochemicals, green tea is believed to have a number of health benefits, including protecting from heart disease, but its mechanism of action at the molecular level is still not understood. Here we explore, by means of atomistic simulations, how the most abundant of the green tea polyphenols, (-)-Epigallocatechin 3-Gallate (EGCg), interacts with the structural C terminal domain of cardiac muscle troponin C (cCTnC), a calcium binding protein that plays an important role in heart contractions. We find that EGCg favourably binds to the hydrophobic cleft of cCTnC consistently with solution NMR experiments. It also binds to cCTnC in the presence of the anchoring region of troponin I (cTnI(34-71)) at the interface between the E and H helices. This appears to affect the strength of the interaction between cCTnC and cTnI(34-71) and also counter-acts the effects of the Gly159Asp mutation, related to dilated cardiomyopathy. Our simulations support the picture that EGCg interacting with the C terminal domain of troponin C may help in regulating the calcium signalling either through competitive binding with the anchoring domain of cTnI or by affecting the interaction between cCTnC and cTnI(34-71).
    PLoS ONE 07/2013; 8(7):e70556. · 3.53 Impact Factor

Full-text (2 Sources)

Available from
May 27, 2014