Figure 4.
Effects of consuming sucrose- and aspartame-sweetened beverages on MIST-induced cortisol. A, The mean ± SE stress task (MIST) induced plasma cortisol concentration change before (preintervention) and 2 weeks after (postintervention) daily (three times per day) consumption of sucrose or aspartame-sweetened beverages. Δ-Cortisol was calculated as the difference between the cortisol values before (0 min) induction of the first MIST run and after the second MIST run was completed (60 min). We included the prestress cortisol concentration and prestress cortisol concentration × visit day terms in the repeated-measures statistical model. As supported by a significant treatment group × visit interaction [F (1, 15) = 4.7, P = .048; effect size (η2p) = 0.36], the cortisol response to the stress task (MIST) was diminished after 2 weeks of consuming sucrose but not aspartame. Log-transformed cortisol concentrations at each sample time are shown for the preintervention (B) and postintervention (C) visits. *, P = .024 for statistical difference in δ-cortisol between sucrose and aspartame groups at the postintervention visit.