Effects of coffee and tea on postprandial cardiometabolic risk factors in healthy individuals: a randomized crossover trial.

BACKGROUND AND OBJECTIVES: The effect of different coffee and tea consumption on postprandial glucose and lipid metabolism has never been reported previously. The aim of the present study was to investigate the effect of different coffee or tea consumption at breakfast on postprandial cardiometabolic risk factors in healthy individuals.

METHODS AND STUDY DESIGN: Eighteen healthy young subjects completed the trial. After 8-hour overnight fast, volunteers either ingested water, freeze-dried coffee, spray-dried coffee, green tea, black tea or oolong tea together with a breakfast consisting of an egg and 180g deep-fried dough sticks. Blood was drawn at 0h, 0.5h, 1h, 2h, and 3h.

RESULTS: The differences in triglyceride (TG) values relative to the baseline levels at 2h and 3h of green tea was significantly decreased compared with black tea and oolong tea (p<0.05). Compared with black tea, green tea and oolong tea significantly reduced postprandial total cholesterol (TC) levels (p<0.05, p<0.01), respectively. Furthermore, the serum concentrations of high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were substantially decreased after oolong tea consumption compared with black tea (p<0.05, p<0.01).

CONCLUSIONS: Green tea ingestion can lower the elevation of serum TG and TC levels after high-fat or high-cholesterol diets. Our findings have far-reaching implications given the widespread use of coffee and tea and the current concern over cardiometabolic risk factors.