Abstract

Eleven subjects participated in an 8 week, randomly assigned, balanced, cross-over study that assessed oxalate absorption from supplemental doses of cinnamon and turmeric. The oxalate content of cinnamon and turmeric were 1789 mg/100g and 1969 mg/100g, respectively. Oxalate load tests were performed after 4 weeks of cinnamon and turmeric consumption and at the study onset with water only (control treatment). Compared to the cinnamon and control treatments, turmeric ingestion led to a significantly higher urinary oxalate excretion for samples collected at 2, 4 and 6 hr post oxalate ingestion (cinnamon) or water ingestion (control). There were no significant differences between the cinnamon and control treatments. The percentage of oxalate that was water soluble differed markedly between cinnamon (6%) and turmeric (91%), which appeared to be the primary cause of the greater urinary oxalate excretion/oxalate absorption from turmeric. In summary, consumption of supplemental doses of turmeric, but not cinnamon, can significantly increase urinary oxalate levels thereby increasing risk of kidney stone formation in susceptible individuals.