Aspartame ingestion increases urinary calcium, but not oxalate excretion, in healthy subjects

Aspartame is the artificial sweetener most extensively used as a substitute for glucose or sucrose in the food industry, particularly in soft drinks. As glucose ingestion increases calciuria and oxaluria, the two main determinants of urinary calcium-oxalate saturation, we considered it worthwhile to determine whether aspartame ingestion also affects calcium-oxalate metabolism. Our study compares the effects of the ingestion of similarly sweet doses of aspartame (250 mg) and glucose (75 g) on calcium and oxalate metabolisms of seven healthy subjects. Urinary calcium excretion increased after the intake of both aspartame (+86%; P < 0.01) and glucose (+124%; P < 0.01). This may be due to the rise in calcemia observed after both aspartame (+2.2%; P < 0.05) and glucose ingestion (+1.8%; P < 0.05). The increased calcemia may be linked to the decrease in phosphatemia that occurred after both aspartame (P < 0.01) and glucose (P < 0.01) load. Aspartame did not alter glycemia or insulinemia, whereas glucose intake caused striking increases in both glycemia (+59%; P < 0.001) and insulinemia (+869%; P < 0.01). Although insulin was considered the main calciuria-induced factor after glucose load, it is unlikely that this mechanism played a role with aspartame. Urinary oxalate excretion did not change after aspartame, whereas it increased (+27%; P < 0.05) after glucose load. Thus, as aspartame induced a similar increase in calciuria as did glucose but, conversely, no change in oxaluria, substituting glucose by aspartame in soft drinks may appear to be of some potential benefit.