Acute effects of Zamzam water on blood pressure and heart rate variability.

Objective: There is a lack of studies exploring the effects of Zamzam water on human physiology. The present study determined the effects of Zamzam water on blood pressure and heart rate variability (HRV).

Methods: This comparative interventional study was conducted at the Department of Physiology, of our university in March 2018. A total number of 97 female subjects drank 500 ml of either Zamzam water or mineral water in one minute. Finometer Pro and PowerLab (ADInstruments) with ECG electrodes through bioamplifier and attached finger pulse transducer were used to collect data at the baseline (for five minutes), during (for one minute) and after the drink (for five minutes). Paired and uunpaired student's t-test, one-way ANCOVA and one-way repeated measure ANOVA were used for analysis. Blood pressure parameters were followed minute by minute and HRV parameters were compared as a 5-minute of baseline segment to 5-minute post drink segment.

Results: Within-the-group comparison exhibited significant increases in blood pressure parameters (systolic, diastolic, pulse and mean arterial pressure), over a 5-minute post-drinking period in both groups. Zamzam water caused a significant increase in SDRR (an indication of overall HRV) and RMSSD (an indication of vagal activity) as compared to baseline.

Conclusion: Both drinks cause a significant increase in systolic, diastolic, pulse and mean arterial pressure within five minutes post-drinking period. Zamzam water produce a significant increase in cardiac vagal tone but has no effect on cardiac sympathetic activity. Mineral water has no significant effect on both, cardiac vagal and sympathetic activity.