Effect of sucrose on the metabolic disposition of aspartame

Twelve normal adult subjects ingested a beverage providing 0.136 mmol aspartame/kg body wt on 2 different days. On 1 study day the beverage provided only aspartame, on the other the beverage provided both aspartame and 3.51 mmol sucrose/kg body wt. The high mean plasma phenylalanine concentrations were similar after administration of aspartame alone (158 ± 28.9 μmol/L,x̄± SD) and administration of aspartame plus sucrose (134 ± 44.1 μmol/L). Evaluation of the area under the plasma concentration-time curve (AUC) for phenylalanine also showed no significant difference between groups (197 ± 49.1 vs 182 ± 28.3 μmol.L−1·h for aspartame alone and aspartame plus sucrose, respectively). Similarly, the high mean ratio of phenylalanine to large neutral amino acids (Phe:LNAA) in plasma did not differ significantly (0.265 ± 0.046 for aspartame alone, 0.275 ± 0.107 for aspartame plus sucrose). However, there was a small but significant difference between groups for the 4-h AUC values for plasma Phe:LNAA. The simultaneous ingestion of sucrose with aspartame had only minor effects on aspartame’s metabolic disposition.