Research has shown that both dark chocolate and exercise training may have favorable effects on antioxidant function in obese cohorts. However, their combined effect has not been established. We assessed the influences of six weeks of dark chocolate consumption combined with jump rope exercise on antioxidant markers in adolescent boys with obesity. Fifty adolescent boys with obesity (age = 15 ± 1 years) were randomly assigned into one of four groups; jump rope exercise + white chocolate consumption (JW; n = 13), jump rope exercise + dark chocolate consumption (JD; n = 13), dark chocolate consumption (DC; n = 12), or control (C; n = 12). Two participants dropped out of the study. Participants in JW and JD groups performed jump rope exercise three times per week for six weeks. Participants in the DC and JD groups consumed 30 g of dark chocolate containing 83% of cocoa during the same period. Serum concentrations of superoxide dismutase (SOD), total antioxidant capacity (TAC), glutathione peroxidase (GPx), and thiobarbituric acid reactive substances (TBARS) were evaluated prior to and after the interventions. All 3 intervention groups noted significant (p < 0.01) increases in serum concentrations of TAC, SOD, and GPx from baseline to post-test. In contrast, all intervention groups showed significantly reduced serum concentrations of TBARS from pre- to post-test (p ≤ 0.01). Bonferroni post hoc analysis revealed that post-test serum concentrations of TAC in the JD group were significantly greater than C (p < 0.001), DC (p = 0.010), and JW (p < 0.001) groups. In addition, post-test serum concentrations of SOD in the JD group were significantly greater than C group (p = 0.001). Post-test serum concentrations of GPx in the JD group were significantly greater than C (p < 0.001), DC (p = 0.021), and JW (p = 0.032) groups. The post-test serum concentrations of TBARS in the JD group was significantly lower than C (p < 0.001). No other significant between-group differences were observed. The current study provides evidence that dark chocolate consumption in combination with jump rope exercise is more efficient in improving antioxidant capacity than dark chocolate consumption or jump rope exercise alone among obese adolescent boys.
Keywords: antioxidants; body composition; dark chocolate; metabolic syndrome; obesity.