Objective: 1. To investigate the amount of citrate and tartrate in aloe gel, and in the urine of healthy normal volunteers, before and after consuming fresh aloe gel. 2. To evaluate the changes in the chemical composition of urine among subjects after taking aloe gel. 3. To determine the value of consuming aloe gel for prevention of renal stone formation.
Designs: Experimental study; before and after experiment with no control group
Material and method: Thirty one healthy male medical students between 18 and 23 years of age were enrolled (with informed consent) in the clinical trial. Subjects ingested 100 g of fresh aloe gel twice a day for seven consecutive days. The 24-hr urine was collected one day prior to taking the gel (Day 0), Days 2 and 5 of consumption, and Day 8 (one day after completion). The authors determined the urine volume, osmolality, potassium, sodium, phosphate, calcium, magnesium, uric acid, citrate, tartrate, oxalate, Permissible Increment in calcium (PI in calcium), Permissible Increment in oxalate (PI in oxalate), Concentration product ratio of calcium phosphate (CPR of CaPO4) and the citrate per creatinine ratio.
Results: The citrate and tartrate concentration in 100 g of fresh aloe gel was 96.3 and 158.9 mg, respectively. The urinary excretion of oxalate was significantly decreased (p < 0.05). The PI in calcium was significantly increased (p < 0.05), while the citrate excretion and PI in oxalate were consistently, albeit non-significantly, increased. The mean CPR values of CaPO4 were decreased non-significantly. The other measurements were unremarkable.
Conclusion: Fresh Aloe vera gel (100 g) contains 96.3 mg of citrate and 158.9 mg of tartrate. This is mid-range for Thai fruits. Changes in chemical compositions of urine after aloe consumption shows its potential for preventing kidney stone formation among adults.