The effect of nigella sativa supplementation on cardiometabolic outcomes in patients with non-alcoholic fatty liver: A randomized double-blind, placebo-controlled trial

Background and purpose: Non-alcoholic fatty liver disease (NAFLD) is one of the metabolic disturbances associated with liver cell inflammation. Nigella sativa (N.sativa) is a widely used medicinal plant known for its anti-inflammatory, antimicrobial, antioxidant, and hepato-protective properties. This study aimed to assess the effect of supplementation of N. sativa oil on plasma levels of adiponectin, leptin, and blood pressure (BP) in patients diagnosed with NAFLD. Materials and methods: This randomized, double-blind, placebo-controlled clinical trial was conducted on 44 NAFLD patients. Participants were randomly assigned to two groups (n = 22/group); the experimental group received 1000 mg of N. sativa oil per day, while the control group received a placebo for eight weeks. The primary outcome measures were serum levels of adiponectin, leptin, and systolic and diastolic blood pressure measured at the baseline and the end of the intervention. Results: After eight weeks of supplementation with N. sativa oil, no statistically significant differences were found in serum levels of adiponectin (p = 0.40), leptin (p = 0.89), systolic BP (p = 0.13), and diastolic BP (p = 0.09) between the two groups. Furthermore, after supplementation with N. sativa, no significant changes were observed in leptin (p = 0.07), adiponectin (p = 0.13), systolic BP (p = 0.82), and diastolic BP (p = 0.38) within the two groups. Conclusion: These results indicate that administration of N. sativa oil 1000 mg/day for 8 weeks has no favorable effect on cardiometabolic measures in NAFLD patients. Further studies with higher dosage over a longer period are needed to investigate whether this effect is dose-and time-dependent.