Antihypertensive effects of Nigella sativa: Weighing the evidence

Objective: Hypertension causes 7.5 million deaths annually worldwide. Antihypertensive drugs cause side effects, potentially leading to non-adherence, hence uncontrolled hypertension and increased risk of cardiovascular morbidity and mortality. Therefore, there has been increasing interest in alternative pharmacological treatments for hypertension, one of which is black cumin, or Nigella sativa, a traditional medicine that has been empirically used. This evidence-based case report aims to evaluate the current evidence for the effectiveness of Nigella sativa in reducing blood pressure in a mildly hypertensive patient. Methods: A literature search was performed on MEDLINE, TRIP Database, Clinical Key, ScienceDirect, and DynaMed, using the keywords “nigella sativa”, “hypertension”, and “blood pressure” with all their synonyms and related terms. The included studies were two systematic reviews and two clinical trials, which were then critically appraised. Results: Out of the four studies, three were considered valid. In terms of importance, Sahebkar et al. showed a reduction of the weighted mean difference (WMD) by Nigella sativa: −3.26 mmHg, 95% CI: −5.10, −1.42, I2 = 59% for systolic blood pressure and WMD: −2.80 mmHg, 95% CI: −4.28, −1.32, I2= 60% for diastolic blood pressure. Badar et al. concluded that Nigella sativa significantly reduced systolic and diastolic blood pressure compared with the control group. Two studies were considered applicable to our patient in question. Conclusion: The current evidence for the effect of Nigella sativa in lowering blood pressure is limited. However, one study gives strong evidence for significant antihypertensive effects of Nigella sativa. In mild hypertension, Nigella sativa could be one of the therapeutic options.