Effects of saffron (Crocus sativus L.) on anthropometric and cardiometabolic indices in overweight and obese patients: A systematic review and meta-analysis of randomized controlled trials.

The worldwide prevalence of obesity is approximately tripled between 1975 and 2016 according to World Health Organization; therefore, obesity is now considered a global pandemic that needs academic and clinical focus. In search of antiobesity agents, Crocus sativus, known widely as saffron, has been praised for its beneficial effects. Several randomized controlled trials (RCTs) have been conducted to investigate the weight lowering effect of saffron. Following PRISMA guidelines, several medical databases were comprehensively searched for RCTs with a population consisting of obese individuals. A random-effects meta-analysis was used to pool estimates across studies, and standardized mean difference (SMD) was used to synthesize quantitative results. Twenty-five RCTs met the inclusion criteria. Meta-analysis showed a nonsignificant decrease for weight (-0.32 kg; CI: -3.15, 2.51; p = 0.82), BMI (-0.06 kg/m ;CI:-1.04,0.93; p = .91), waist circumference (-1.23 cm; CI: -4.14, 1.68; p = .41), and hip circumference (-0.38 cm; CI: -5.99, 5.23; p = .89) and a significant decrease of waist-to-hip ratio (SMD = -0.41; CI: -0.73, -0.09; p = .01; I  = 0%). The mean difference in fasting blood sugar showed a significant reduction in patients with metabolic syndrome (SMD = -0.30; 95% CI: -0.63, 0.03; p = .07; I  = 0.37%) but a nonsignificant change in the HbA1C level (WMD = 0.05; 95% CI: 0.32, 0.41; p = .79). Despite bearing several limitations, mainly as a result of heterogeneity among included studies, the available evidence indicates saffron supplementation shows promising effects on some cardiometabolic factors among overweight to obese patients; however, further investigations and high-quality evidence are required for more generalizable and comprehensive results.