4 Antihypertensive Effect of Nigella Sativa (Habbatus Sauda) Supplementation in Population With Cardiometabolic Risk Factors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Abstract

Background: Nigella sativa or Habbatus Sauda is known to have beneficial effect to reduce blood pressure and other cardiovascular markers. But antihypertensive effect of N. sativa in hypertensive population remains controversial.Objective: We aim to assess the latest evidence of antihypertensive effect of N. sativa in patients with cardiometabolic risk factors.Method: A systematic review and meta-analysis was conducted according to the PRISMA statement. We systematically searched relevant studies in Pubmed, Cochrane, and Scopus from the date of inception until January 2022. Outcomes of interest were reduction of systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate.Results: A total of 974 patients from 13 randomized controlled trials were included. Mean duration of treatment was 7.15 weeks. Pooled analysis showed that N. sativa supplementation significantly reduce both SBP (MD -3.93 [-5.72, -2.14], p<0.0001; I2: 39%, p=0.07) and DBP (MD -3.26 [-4.76, -1.75], p<0.0001; I2: 54%, p=0.01) compared to placebo group. Subgroup analysis showed that BP was reduced significantly in both hypertensive and non-hypertensive group, although non-hypertensive group had greater SBP and DBP reduction. NS powder showed greater SBP reduction compared to NS oil (MD -5.22 vs -2.77). Heart rate was also significantly reduced in NS group (MD -2.25 [-2.25, -0.54], p<0.001; I2: 0%, p=0.86).Conclusion: This meta-analysis suggests short-term treatment with N. sativa is associated with significant reduction of SBP, DBP, and heart rate in hypertensive and non-hypertensive patients with cardiometabolic risk factors. Future trials are needed to strengthen the evidence of long-term antihypertensive effect of N. sativa.