Acute Capillary Glucose Responses to Sweetened Beverages, Spice Infusions, and Mineral-Rich Water in Healthy Young Adults: A Randomized Parallel-Group Study

Beverage carbohydrate content is a major determinant of acute glycemia, whereas responses to unsweetened spice infusions and mineral-rich water remain uncertain. This randomized, controlled, parallel-group study compared six beverages in healthy university students aged 19–25 years after an overnight fast. In total, 180 participants were randomly assigned using permuted blocks with allocation concealment (30/group) to 250 mL of orange juice, a honey drink, ginger infusion, cinnamon infusion, Zamzam water, or plain bottled water; outcome assessors were blinded. A protocol analysis included 144 participants (24/group). Capillary glucose, based on triplicate readings, was assessed before and 60 min after consumption. Within-group changes were assessed using paired t-tests and compared across groups using one-way analysis of variance. Mean glucose increased after honey (+20.09 mg/dL; 95% CI, 15.50–24.68; p < 0.0001) and orange juice (+17.33 mg/dL; 95% CI, 6.10–28.56; p = 0.0058). Changes after cinnamon (−3.58 mg/dL), ginger (−3.91 mg/dL), and plain water (−2.84 mg/dL) were not statistically significant. Zamzam water produced a within-group increase (+9.83 mg/dL; 95% CI, 5.20–14.46; p = 0.0003), with a post-consumption mean of 89.00 mg/dL. Overall changes differed among groups (p < 0.0001). The Zamzam findings are exploratory and require confirmation using standardized beverage composition, repeated measurements, and direct between-group estimates.