Effects of Chocolate Intake on Oxidative Stress/Oxidant-antioxidant Balance in Medical Students: A Controlled Clinical Trial

BACKGROUND AND AIM: Cocoa polyphenols have been shown to exhibit antioxidant properties in vivo and in vitro. This study aimed to determine whether commercially available chocolate could improve oxidant/antioxidant balance in medical students. MATERIALS AND METHODS: Sixty students (30 males and 30 females) were given three different types of chocolate. Subjects were divided equally into three groups of 20 students (10 males and 10 females) as follows: (i) Dark chocolate group (DC), (ii) milk chocolate group (MC), and (iii) placebo group (PC). The placebo group was given white chocolate. Blood was drawn at baseline and after consumption of chocolate (40 g/day) for 2 weeks. Serum was analyzed for DNA/RNA oxidative damage, thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), and glutathione peroxidase (GPX) enzymes. Descriptive analyses were conducted to determine the frequency distributions of the study variables. Means were compared across the study groups by one-way Analysis of Variance and within the same group by paired t-test. RESULTS: Mean serum DNA/RNA damage, TBARS, SOD, and GPX enzymes compared between the groups revealed insignificant differences after 2 weeks of chocolate consumption (P = 0.46, 0.19, 0.11, and 0.06). Comparison within the same group also exhibited statistically insignificant differences in DNA/RNA damage in DC and MC groups (0.29 and 0.46, respectively); TBARS in DC and MC groups (0.11 and 0.19, respectively); SOD in DC and MC groups (0.06 and 0.11, respectively); and GPX in DC and MC groups (0.68 and 0.78, respectively). CONCLUSION: Consumption of 40 g of DC or MC daily for a period of 2 weeks appears to be an ineffective way of improving oxidant/antioxidant balance in medical students.