Effects of Energy Shots on Blood Pressure in Caffeine-Naive Versus Caffeine-Consuming Healthy Volunteers

Abstract

Background:

As energy drink consumption has grown, there has been increasing concern regarding their safety. Previous studies have shown caffeinated energy drinks significantly increase systolic blood pressure compared to decaffeinated drinks. However, the difference in response between caffeine-naive and caffeine-consuming individuals is not fully understood.

Methods:

Individual patient-level data from two randomized, double-blinded controlled studies were combined and analyzed. Healthy subjects in both studies received a regular caffeinated and a decaffeinated, 2-oz energy shot separated by a 6-day washout period. Blood pressure and heart rate were recorded at baseline, 1, and 3 hours after consumption. Subjects were categorized as caffeine naive (consuming <1 cup of caffeinated beverage a day) or caffeine consuming (consuming ≥1 cup of caffeinated beverages a day). Data were analyzed using the unpaired Student's t-test.

Results:

A total of 30 subjects were included, with 20 categorized as caffeine naive and 10 as caffeine consumers. Increases in systolic blood pressure were 7.18 ± 6.58 mmHg in the caffeine-naive group compared to 2.40 ± 5.65 mmHg in the caffeine-consuming group 1 hour after a caffeinated energy shot (p = 0.05). Diastolic blood pressure and heart rate changes were similar between the two groups after consumption of the caffeinated energy shot. The decaffeinated energy shot had a similar effect on the two groups.

Conclusions:

Caffeine-naive individuals experienced an approximately threefold greater increase in systolic blood pressure 1 hour after consumption of a caffeinated energy shot compared to caffeine-consuming individuals.