Black Seed Oil (Nigella sativa) Improves Vascular Function in Adults with Pre-Existing Risk Factors for Cardiovascular Disease

by | Aug 17, 2022 | 2022, Cardiovascular Health, Essential Oils

Written by Taylor Woosley, Staff Writer. 2-month supplementation of 500 mg N. sativa oil resulted in a significant increase in FMD and plasma NOx levels (2.97 ± 2.11% vs. 0.71 ± 3.19%, p < 0.001 for FMD and 4.73 ± 7.25 µmol/L vs. 0.99 ± 5.37 µmol/L, p = 0.036 for plasma NOx). 

cardiovascular healthCardiovascular diseases (CVD) are the leading cause of death and comorbidity worldwide1. The Global Burden of Cardiovascular Diseases and Risk Factors reported that CVD prevalence has increased from 271 million to 523 million from 1990 to 20192. CVD is a multifactorial disease and includes hypertension, myocardial infarction, and stroke3. Endoplasmic reticulum stress, atherosclerosis, and oxidative stress are believed to play a role in CVD pathogenesis4.

Recent studies have shown that Nigella sativa, also known as black seed oil, can be effective in preventing and treating a variety of cardiovascular and inflammatory conditions5. Phytochemical analysis has reported the presence of various chemical compounds of N. sativa, such as phospholipids, fatty acids, vitamins, and ascorbic acid6. Oil extracted from black seed oil contains several sterols, making it an effective natural agent for lowering blood cholesterol and preventing cardiovascular diseases7. Thymoquinone (TQ), a flavonoid derived from N. sativa, is reported to have anti-inflammatory, antioxidant, and cardiovascular protective properties8.

To better explore the potential cardioprotective benefits of N. sativa, Emamat et al. conducted a single center, single-blinded, parallel assigned, randomized controlled trial. Subjects were recruited if they had at least one risk factor for cardiovascular disease. Other inclusion criteria included being between 20-65 years old, BMI < 30, and no supplementation of vitamins or minerals for 2 weeks. Participants completed a questionnaire related to their anthropometric measurements, demographic status, disease history, drug use, smoking status, and physical activity. Subjects (n=47) were randomly assigned to the N. sativa group (n= 23) or the placebo group (n=24). The intervention group received two capsules containing 500 mg of N. sativa oil and placebo received two capsules containing 500 mg of mineral oil daily. Capsules were consumed 30 minutes before mealtime during the 2-month period of the study. N. sativa oil capsules containing at least 6.5 mg TQ and 495 to 605 linoleic acid per soft capsules. Subjects’ adherence to supplementation was tracked every 2 weeks by phone call.

Blood samples, obtained after a 12-hr fasting period, were used to measure plasma NO-derived end products (NOx). Brachial artery flow-mediated dilation (FMD) measurements were performed by a radiologist. Primary outcome variables were changes in FMD. Statistical analyses were performed, along with the Shapiro-Wilk test to verify the normality of data. Furthermore, mean and standard deviations or frequency and percent were used to determine quantitative and qualitative variables. Independent t-test and Chi-square (x2) tests were used to observe within-group differences. Final analysis included the use of ANCOVA test to compare 2-month values of FMD and inflammatory biomarkers between the two groups. Significant findings of the 2-month trial are as follows:

  • FMD values were similar between groups at baseline but were significantly higher in sativa after 2 months (0.27 ± 0.11 mm or 6.41 ± 2.96% and 0.15 ± 0.09 mm or 3.80 ± 2.56% for N. sativa and placebo group; respectively).
  • Intragroup comparisons revealed that FMD values increased significantly in the sativa group (p < .001). After adjusting for baseline values, a significant increase was observed in FMD values in the N. sativa group when compared to placebo (p < .001 and p = .001 for FMD (mm) and FMD (%), respectively).
  • Plasma levels of NOx were significantly increased in sativa group after 2 months (42.63 ± 12.66 to 47.37 ± 13.99 µmol/L, p = .003). Plasma levels of NOx in the placebo group did not change significantly after 2 months (37.39 ± 11.08 to 38.38 ± 11.84 µmol/L, p = .36).

Findings of the trial show that supplementation of 500 mg of N. sativa oil significantly improved NOx levels and FMD values. These results suggest that N. sativa effectively improves vascular function in subjects with at least one risk factor for CVD. Future studies should observe the potential positive effects of N. sativa on various other biomarkers of inflammation and CVD risk. Study limitations include the short duration of the study and its inability to detect the potential impact of N. sativa on anti-inflammatory vascular biomarkers and the lack of assessment of other biomarkers related to endothelial function.

Source: Emamat, Hadi, Seyyed Hossein Mousavi, Jalal Kargar Shouraki, Ebrahim Hazrati, Sayid Mahdi Mirghazanfari, Esmaeil Samizadeh, Maryam Hosseini, Vahid Hadi, and Saeid Hadi. “The effect of Nigella sativa oil on vascular dysfunction assessed by flow‐mediated dilation and vascular‐related biomarkers in subject with cardiovascular disease risk factors: A randomized controlled trial.” Phytotherapy Research 36, no. 5 (2022): 2236-2245.

© 2022 John Wiley & Sons, Ltd.

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Posted August 17, 2022.

Taylor Woosley studied biology at Purdue University before becoming a 2016 graduate of Columbia College Chicago with a major in Writing. She currently resides in Glen Ellyn, IL.

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