File:Only green tea increased flow-mediated dilation but not EGCG (cardio health).webp

English: "Only green tea increased flow-mediated dilation (FMD). Subjects consumed 200 mg of EGCG as isolated EGCG, GTE, or green tea after fasting overnight. An equal volume of hot water served as control. Green tea significantly increased FMD compared to GTE, EGCG, and water as control. Water slightly decreased FMD, whereas EGCG and GTE had little effects. Data are means ± SEM from n = 50 subjects. All p-values by repeated measures ANOVA followed by post hoc Bonferroni."

EGCG = epigallocatechin gallate

"Consumption of tea is inversely associated with cardiovascular diseases. However, the active compound(s) responsible for the protective effects of tea are unknown. Although many favorable cardiovascular effects in vitro are mediated by epigallocatechin gallate (EGCG), its contribution to the beneficial effects of tea in vivo remains unresolved. In a randomised crossover study, a single dose of 200 mg EGCG was applied in three different formulas (as green tea beverage, green tea extract (GTE), and isolated EGCG) to 50 healthy men. Flow-mediated dilation (FMD) and endothelial-independent nitro-mediated dilation (NMD) was measured before and two hours after ingestion. Plasma levels of tea compounds were determined after each intervention and correlated with FMD. FMD significantly improved after consumption of green tea containing 200 mg EGCG (p < 0.01). However, GTE and EGCG had no significant effect on FMD. NMD did not significantly differ between interventions. EGCG plasma levels were highest after administration of EGCG and lowest after consumption of green tea. Plasma levels of caffeine increased after green tea consumption. The results show that EGCG is most likely not involved in improvement of flow-mediated dilation by green tea. Instead, other tea compounds, metabolites or combinations thereof may play a role."