Acute effects of consumption of low-caffeine energy drinks on endothelial functions in healthy volunteers

Abstract

Energy drink consumption is increasing among the population, especially adolescents and young adults. The health effects of energy drinks are unknown. In this study, we investigate the effects of low caffeine energy drinks on endothelial functions assessed by flow-mediated dilation (FMD) of the brachial artery. Thirty healthy volunteers (15 men, 15 women) aged 19 to 46 years participated in the study. Flow-mediated dilation measurements of the brachial artery were performed and recorded per protocol. The volunteers were asked to drink 355 mL of energy drink containing 53.25 mg of caffeine after baseline measurements, and all measurements were repeated 60 minutes later. Baseline and post-energy drink values were compared. Systolic blood pressure (p=0.592), diastolic blood pressure (p=0.714), and heart rate values (p=0.056) were similar before and after the consumption of energy drinks. Preocclusion arterial diameters (p=0.236) and blood velocities (p=0.447) did not change after energy drink consumption. FMD levels were 9.2%±4.6% and 8.1%±4.7%, respectively, before and after energy drink consumption (p=0.176). Women had a 3% increase in preocclusion arterial diameters after energy drink consumption, whereas men had a 2.6% decrease (p=0.026) Conclusion: Low caffeine energy drinks containing 53.25 mg of caffeine/355 mL can did not have any influence on blood pressure, heart rate, or endothelial functions in healthy volunteers.