Acute effects of energy drinks in medical students.
OBJECTIVE
To determine the acute effects of a variety of recognized energy drinks on medical students, based on the hypothesis that these beverages may affect negatively cardiovascular parameters, stress levels and working memory.


METHODS
Eighty young healthy medical students were included in the study. 62.5 % of the participants were male, and the age mean was 21.45 years. Each person was evaluated via measurement of systolic and diastolic blood pressure, electrocardiogram (ECG), heart rate, oxygen saturation, breath rate, temperature, STAI score (to assess anxiety state), salivary cortisol and N-back task score (to determine cognitive enhancement). These evaluations were performed before and following the intake of either carbonated water or one of three energy drinks containing caffeine in similar concentrations and an undetermined energy blend; A contained less sugar and no taurine.


RESULTS
Thirty-minute SBP increased significantly in the A and C groups. The B group exhibited a diminution of the percentage of the 1-h SBP increase, an increase of 1-h DBP and QTc shortening. HR showed an increase in the percent change in the A and C groups. Cortisol salivary levels increased in the B group. The STAI test score decreased in the C group. The percent change in N-back scores increased in the A group.


CONCLUSIONS
The data reinforce the need for further research on the acute and chronic effects of energy drinks to determine the actual risks and benefits. Consumers need to be more informed about the safety of these energy drinks, especially the young student population.
Faculty of Health Sciences, Universidad Tecnológica de Pereira, AA 97, La Julita, Pereira, Colombia.
Andrés
A
García
Faculty of Health Sciences, Universidad Tecnológica de Pereira, AA 97, La Julita, Pereira, Colombia.
César
C
Romero
Faculty of Health Sciences, Universidad Tecnológica de Pereira, AA 97, La Julita, Pereira, Colombia.
Cristhian
C
Arroyave
Faculty of Health Sciences, Universidad Tecnológica de Pereira, AA 97, La Julita, Pereira, Colombia.
Fabián
F
Giraldo
Faculty of Health Sciences, Universidad Tecnológica de Pereira, AA 97, La Julita, Pereira, Colombia.
Leidy
L
Sánchez
Faculty of Health Sciences, Universidad Tecnológica de Pereira, AA 97, La Julita, Pereira, Colombia. jcsanchez@utp.edu.co.
Julio
J
Sánchez
D000293:Adolescent; D000328:Adult; D001794:Blood Pressure; D015992:Body Mass Index; D002110:Caffeine / Q000008:administration & dosage; D000073417:Dietary Sugars / Q000008:administration & dosage; D004562:Electrocardiography; D061215:Energy Drinks / Q000009:adverse effects*; D005260:Female; D006339:Heart Rate; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis*; D008297:Male; D012463:Saliva / Q000737:chemistry; D013337:Students, Medical; D013654:Taurine / Q000008:administration & dosage; D014815:Vitamins / Q000008:administration & dosage; D055815:Young Adult
D000073417:Dietary Sugars; D014815:Vitamins; D013654:Taurine; D002110:Caffeine; D006854:Hydrocortisone
Blood pressure; Caffeine; Cortisol; Energy drink; Medical students; Taurine