Acute effects of dietary caffeine and sucrose on urinary mineral excretion of healthy adolescents

Abstract

Eighteen adolescents (nine males and nine females, ages 13–18), on four separate mornings drank, in a caffeine-free soft drink, 0 and 3 mg/kg caffeine and 0 and 30 g of sucrose in a two by two factorial experiment. Caffeine increased total three hour post treatment urinary calcium from 16.0 mg to 20 mg (without sucrose) and 29.6 mg (with sucrose). Sodium, chloride and potassium excretion were also increased after caffeine ingestion, but not phosphorus and magnesium. Sucrose ingestion reduced total sodium and potassium excretion, but did not affect calcium, magnesium or phosphorus. After caffeine consumption, sodium and chloride concentrations increased. A sex/caffeine interaction was apparant in calcium concentration after caffeine consumption, as only females exhibited an increased concentration. After sucrose, calcium concentration increased. Sucrose and caffeine did not interact in this study, except on the excretion of potassium. The presence of caffeine and sucrose in a soft drink increased the 3 hour total urinary calcium excretion compared to a caffeine-free drink with a non-nutritive sweetener.