Oolong tea increases plasma adiponectin levels and low-density lipoprotein particle size in patients with coronary artery disease

Background: Oolong tea has been studied for its effect on cardiovascular disease and obesity. Plasma adiponectin levels are reduced in obesity, in patients with type 2 diabetes mellitus and in coronary artery disease (CAD). Objective: To investigate prospectively, whether intake of Oolong tea influences plasma adiponectin levels, low-density lipoprotein (LDL) particle size, total cholesterol, high-density lipoprotein (HDL) cholesterol, LDL cholesterol, serum triglyceride and plasma glucose levels in patients with CAD. Methods: Twenty two patients in our study consumed Oolong tea (1000 ml) or water for 1 month in our randomized cross-over study design. Results: There was a significant difference in plasma adiponectin levels before and after 1 month intake of Oolong tea (6.26 +/- 3.26 mug/ml versus 6.88 +/- 3.28 mug/ml, P < 0.05), and in plasma level LDL particle size (25.02 +/- 0.67 nm versus 25.31 +/- 0.60 nm, P < 0.01). The water-consuming control group showed no changes (6.28 +/- 3.28 mug/ml versus 6.23 +/- 3.21 mug/ml) in adiponectin levels or LDL particle sizes (25.03 +/- 0.70 nm versus 25.02 +/- 0.72 nm). We also observed a significant difference in hemoglobin Alc levels (7.23 +/- 4.45% versus 6.99 +/- 4.30%, P < 0.05) before and after intake of Oolong tea. Conclusion: Oolong tea may have beneficial effects on the progression of atherosclerosis in patients with CAD. (C) 2004 Elsevier Ireland Ltd. All rights reserved.