Background: Oxidative stress and inflammation play pivotal roles in the pathophysiology of obesity and depression. This study aimed to evaluate the effects of sumac (Rhus coriaria L.) on anthropometric indices, oxidative stress, inflammation, and depression in overweight or obese depressed women.

Methods: This randomized, double-blind, placebo-controlled clinical trial was conducted on overweight or obese women aged 20-65 years with mild to moderate depression. The participants (n = 62) were assigned to receive a restricted calorie diet (RCD) plus 3 g/day of either sumac or placebo for 12 weeks. Anthropometric measurements, biochemical biomarkers, and the Beck depression inventory were assessed during the study.

Results: Sumac significantly reduced weight, body mass index, body fat (p < .001), visceral fat level (p = .03), waist and hip circumference, and malondialdehyde levels (p = .03, p = .002, and p = .006, respectively) in comparison with the placebo group. The levels of interleukin-6 and tumor necrosis factor-α decreased only in the sumac group (11 and 32%, respectively); however, these reductions were not significant. The high-sensitivity c-reactive protein levels (p = .007 and p = .01, respectively) and Beck scores (p < .001) decreased significantly in both the sumac and the placebo group without any significant difference between the two groups.

Conclusion: Sumac can be considered as a functional food that along with RCD could have beneficial effects on obesity management, through the possible modulatory effects on oxidative stress in overweight or obese depressed women.

Keywords: Rhus coriaria L.; depression; inflammation; obesity; oxidative stress; sumac.