Effect of Red Bull energy drink on cardiovascular and renal function.

Energy drink consumption has been anecdotally linked to the development of adverse cardiovascular effects in consumers, although clinical trials to support this link are lacking. The effects of Red Bull energy drink on cardiovascular and neurologic functions were examined in college-aged students enrolled at Winona State University. In a double-blind experiment where normal calorie and low calorie Red Bull were compared to normal and low calorie placebos, no changes in overall cardiovascular function nor blood glucose (mg/dL) were recorded in any participant (n = 68) throughout a 2-h test period. However, in the second experiment, nine male and twelve female participants subjected to a cold pressor test (CPT) before and after Red Bull consumption showed a significant increase in blood sugar levels pre- and post Red Bull consumption. There was a significant increase in diastolic blood pressure of the male volunteers immediately after submersion of the hand in the 5 degrees C water for the CPT. Under the influence of Red Bull, the increase in diastolic pressure for the male participants during the CPT was negated. There were no significant changes in the blood pressure of the female participants for the CPT with or without Red Bull. Finally, the CPT was used to evaluate pain threshold and pain tolerance before and after Red Bull consumption. Red Bull consumption was associated with a significant increase in pain tolerance in all participants. These findings suggest that Red Bull consumption ameliorates changes in blood pressure during stressful experiences and increases the participants' pain tolerance.