The effects of green tea ingestion over four weeks on atherosclerotic markers.

BACKGROUND The objective of this study was to evaluate the effects of green tea ingestion over four weeks on atherosclerotic biological markers. METHODS After a one-week baseline period, 12 healthy male volunteers aged 28--42 years drank 600 mL of green tea daily for four weeks. Lipid profile, oxidized low-density lipoprotein (ox-LDL), total antioxidant capacity (TAC), C-reactive protein (CRP) and soluble cell adhesion molecules were measured at baseline and after two and four weeks ingestion of green tea. RESULTS There was no significant change in the concentrations of lipid profile, TAC, CRP, soluble intercellular adhesion molecule-1 (sICAM-1), or soluble E-selectin after ingestion of green tea. The levels of ox-LDL and soluble vascular cell adhesion molecule-1 (sVCAM-1) were significantly decreased after four weeks of green tea ingestion (Wilcoxon signed rank test, P=0.006). CONCLUSIONS The results of this study suggest an in vivo anti-oxidative effect for green tea and an influence of green tea on atherosclerotic biological markers. The effect of green tea seen on ox-LDL and sVCAM-1 provides a potential mechanism for the cardiovascular benefits of regular ingestion of green tea.