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Keywords:

  • energy drinks;
  • 5-hour Energy shot;
  • blood pressure;
  • heart rate;
  • caffeine

Study Objective

To evaluate the effects of a caffeinated 5-hour Energy shot compared with a decaffeinated 5-hour Energy shot as assessed by changes in blood pressure and heart rate in healthy, nonhypertensive volunteers.

Design

Randomized, double-blind, controlled, crossover study.

Setting

University campus.

Subjects

Twenty healthy volunteers.

Intervention

Subjects were randomized to receive either the caffeinated 5-hour Energy shot or the decaffeinated 5-hour Energy shot; after a washout period of at least 6 days, subjects were given the alternate energy shot.

Measurements and Main Results

Systolic (SBP) and diastolic (DBP) blood pressures were recorded for each subject at baseline and at 1, 3, and 5 hours after consumption of the energy shot. Heart rate, adverse effects, and energy levels were also assessed. Mean ± standard deviation (SD) baseline SBP for all study subjects was 114.06 ± 11.30 mm Hg and DBP was 69.53 ± 7.63 mm Hg. Mean changes in SBP between the caffeinated arm and the decaffeinated arm at the 1- and 3-hour time points were significantly increased compared with baseline (mean ± SD 6.08 ± 7.71 mm Hg at 1 hour [p=0.001] vs 3.33 ± 6.99 mm Hg at 3 hours [p=0.042]). Similarly, mean DBP changes between the caffeinated arm and the decaffeinated arm were significantly increased at the 1- and 3-hour time points compared with baseline (mean ± SD 5.18 ± 8.38 mm Hg at 1 hour [p=0.007] and 5.43 ± 7.21 mm Hg at 3 hours [p=0.005]). Heart rate, adverse effects, and energy levels were similar between the two groups.

Conclusion

Caffeinated energy shots significantly increased SBP and DBP over a 3-hour period compared with decaffeinated energy shots in healthy, nonhypertensive individuals.