Does a single cup of caffeinated drink significantly increase blood pressure in young adults? A randomised controlled trial.

ABSTRACT

BACKGROUND: Previous studies have shown that the blood pressure elevating effect of acute caffeine consumption was variable because of the heterogeneity of study participants, dosage of caffeine and study designs. OBJECTIVE: This research aimed to examine the effect of a single cup of coffee on the blood pressure of young adults. METHODS: Normotensive adults were randomised to receive either a cup of caffeinated drink (intervention group) or a cup of decaffeinated drink (control group). The main outcome measure was mean change in systolic blood pressure (SBP) and diastolic blood pressure (DBP) between intervention and control groups. RESULTS: Enrolled participants (n = 104) were randomly assigned to the intervention group (n = 53) or the control group (n = 51). The mean differences in SBP and DBP of the two groups were +2.77 mmHg (P = 0.05) and +2.11 mmHg (P = 0.64), respectively. Therefore, the rise in both SBP and DBP after caffeine consumption was not statistically significant. DISCUSSION: Our study confirmed that drinking a single cup of coffee (containing 80 mg of caffeine) does not have a significant impact on the blood pressure of healthy normotensive young adults one hour after the drink.