Effect of sweetened beverages intake on salivary aspartame, insulin and alpha-amylase levels: A single-blind study

The objective was to assess aspartame excretion in saliva and the salivary insulin, total protein (TP), and alpha-amylase (AMI) levels in response to the ingestion of sweetened beverages (sodium cyclamate, aspartame, acesulfame, and sucrose). Fifteen healthy participants were included in a single-blinded trial with the intake of Diet soft drink, Regular soft drink, Water+sweeteners, Low sucrose content (3.5g), and Water (blank) in 5 different days. In each day, saliva was collected at T0 (fasting), T1 (15 min after test-drink intake), T2 (30 min), T3 (60 min), and T4 (120 min) for the measurement of salivary aspartame (HPLC), TP, AMI (ELISA assays) and insulin levels (chemiluminescence). Chi-square, Friedman, ANOVA and Spearman correlation tests were applied. The late-perceived sweet/sour residual flavor was reported at a frequency of 80%, 60% and 20% after ingestion of artificially sweetened drinks, beverages with sucrose, and plain water, respectively (p<0.05). Aspartame was detected in saliva after artificially sweetened drinks intake, with highest area under the peak for the Diet soft drink (p=0.014). No change was observed for TP and AMI levels during the 120 min. Insulin levels increased 1h after soft-drinks ingestion (regular and diet), while the levels did not change for Low sucrose content and Water+sweeteners test-drinks. Salivary aspartame correlated with insulin levels only after Diet soft drink intake (rho≥0.7; p<0.05). As aspartame can be detected in saliva and swallowed again until completely excreted, these results contribute to the knowledge of the biological fate of artificial sweeteners and the study of health outcomes.