The Effects of Dark Chocolate Consumption on OxidativeStress and Blood Pressure in Patients with Metabolic Syndrome:A Randomized Clinical Trial

Background: Consumption of dark chocolate has been often hypothesized tohave a role in the prevention of chronic diseases. The objective of this study wasto investigate the effects of consumption of dark chocolate (DC) on serumoxidative stress and blood pressure (BP) in patients with metabolic syndrome(MetS). Methods: An 8-week parallel randomized clinical trial involving 114patients with MetS was conducted on stable medication in 2014. Participantswere randomly assigned to three groups: 1) consume 40 g/d DC (40G), 2)consume 20 g/d DC (20G), and 3) consume no DC as the control group (CG).BP, radical scavenging activity of 1-diphenyl-2-picrylhydrazyl (DPPH), andmalondialdehyde (MDA) were measured at baseline and after 8 weeks ofintervention. Results: Mean age, weight, and body mass index (BMI) ofparticipants were 51.38 ± 6.95 y, 77.34 ± 12.86 kg, and 28.65 ± 4.4 kg/m2,respectively. No significant differences were found among the three groups inrelation to these variables after the intervention. The mean change of systolicblood pressure in 40G, 20G, and CG were 0.31 ± 1.81, 0.37 ± 1.65, and 0.26 ±1.56 mmHg (P = 0.3), respectively. These figures for diastolic blood pressurewere obtained as 0.08 ± 1.03, -0.02 ± 1.12, and 0.22 ± 1.03 mmHg. Nosignificant changes were observed in MDA and DPPH between three groups.Conclusion: Even daily intake of 40 g of DC with 76% purity for an 8-weekperiod had no effect on body weight, BMI, BP, and oxidative stress in patientswith MetS.

Keywords:

Cocoa , Dark chocolate , Metabolic syndrome , Oxidative stress biomarkers