The effects of Nigella sativa on anthropometric indices: A GRADE-assessed systematic review and dose-response meta-analysis of controlled trials

This study was done to systematically summarize the available studies that examined the effects of N. sativa supplementation on anthropometric indices among adults. We searched Web of Science, EMBASE, PubMed, Scopus, and Cochrane Library databases until December 2022 to identify relevant studies. All controlled clinical trials that examined the effect of N. sativa supplementation on anthropometric indices were included. Eventually, 32 studies which reported data of interest were entered for data analysis. We found a significant reduction in body weight (WMD: -1.17 Kg, 95% CI: -2.06, -0.28), body mass index (WMD: -0.41 kg/m2, 95% CI: -0.66, -0.16), waist circumference (WMD: -1.12 cm, 95% CI: -1.47, -0.51), and hip circumference (WMD = -1.61 cm, 95% CI: -3.06, -0.17) following supplementation with N. sativa. The results of this study suggest that there was an improvement in anthropometric indices after the use of N. sativa, whereas no changes were observed in waist-to-hip ratio.