Effect of Nigella sativa Consumption on Lipid Profile and Glycemic Index in Patients with Metabolic Syndrome: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

Abstract

Metabolic syndrome is a multifactorial disorder and genetics, lifestyle, and aging play important roles in its prevalence. Nigella sativa has several pharmacological benefits, including anti-inflammatory, antitumor, anti-diabetic, antioxidant, and hypolipidemic effects. This meta-analysis of randomized controlled trials assesses the effect of N. sativa consumption on lipid profile and glycemic indices in patients with metabolic syndrome. We systematically researched Cochrane Library, PubMed, Scopus, and Web of Science databases. The literature research identified 171 studies with duplication. Of those, 73 articles were screened for titles and abstracts, and 7 studies were finally selected for the meta-analysis. Because of the high degree of heterogeneity, we performed subgroup analyses based on the dose of N. sativa (<=500 mg/day or >500 mg/day). The results revealed that N. sativa intake significantly decreased total cholesterol (SMD: -0.71; 95% CI, -1.44 to -0.38; P = 0.00), LDL-C (SMD: -1.06; 95% CI, -1.45 to -0.66; P = 0.00) and HDL-C (SMD: -0.31; 95% CI, 0.09 to 0.53; P = 0.01) concentrations. In addition, N. sativa significantly decreased FBS (SMD: -0.8; 95% CI, -1.21 to -0.39; P = 0.00) and HbA1c (SMD: -0.37; 95% CI, -0.66 to -0.09; P = 0.01) concentrations. No publication bias was observed, and sensitivity analysis showed stable results. The current systematic review and meta-analysis indicates that N. sativa could improve lipid profile and glycemic index in patients with metabolic syndrome.