By David Kiefer, MD
Clinical Assistant Professor, Department of Family Medicine, University of Wisconsin; Clinical Assistant Professor of Medicine, Arizona Center for Integrative Medicine, University of Arizona, Tucson
Dr. Kiefer reports no financial relationships relevant to this field of study.
- One or two grams of black seed daily led to minimal changes in spirometry and laboratory analyses in people with mild-moderate persistent asthma.
Black seed, crushed, in capsule form, administered to 76 people with asthma in a single-blind, randomized study, showed some minimal improvements in some, but not all, components of spirometry and one serum cytokine after 12 weeks.
Salem AM, Bamosa AO, Qutub HO, et al. Effect of Nigella sativa supplementation on lung function and inflammatory mediators in partly controlled asthma: A randomized controlled trial. Ann Saudi Med 2017;37:64-71.
Black seed (Nigella sativa), also known as black cumin, is a flowering plant native to Asia that is developing a reputation for a variety of health concerns. It is a member of the buttercup family (Ranunculaceae) and is used both orally and topically. The physiological effects center on its volatile oils and fatty acids (saturated and unsaturated), which may explain some studies showing decreased inflammation, lipids, glucose, blood pressure, pain, and anxiety, as well as other cardiovascular effects.1,2
Dovetailing from the plant’s anti-inflammatory effects, as well as some evidence for bronchodilation, Salem et al randomized people with “partially controlled asthma” into three groups: a placebo (one capsule twice daily) group (n = 24), 500 milligrams of black seed (whole ground seeds in capsules) twice daily (n = 26), or one gram of black seed twice daily (n = 26) for three months and followed their lung function. The study participants’ asthma control included inhaled corticosteroids with as-needed use of inhaled beta-agonists; the use of other asthma medications prompted exclusion from this study. This was a single-blind study, in that only the participants were blind to their randomization. At baseline, six weeks, and 12 weeks, the participants underwent an Asthma Control Test (a standardized asthma severity rating) analyses, clinical assessment, spirometry, and laboratory analyses (blood testing for serum total immunoglobulin E [IgE] and cytokines, the latter only at time 0 and 12 weeks).
There was no difference between the three groups with respect to baseline lung function. An intention-to-treat analysis found changes over 12 weeks in the participants (placebo [n = 22], 1 gram of black seed daily [n = 2], and 2 grams of black seed daily [n = 25]) who were able to finish the study. Notably, when compared to the other groups, in the higher-dose black seed group, FEV1% was significantly higher (P < 0.05) at 12 weeks, and the FEV1/FVC% and FEF25-75% were higher at six weeks. Interestingly, none of the other spirometry findings were statistically different at any of the time points. With respect to serum cytokines and IgE, only one (IFN-gamma) showed any difference with black seed treatment, a decrease in both doses at 12 weeks when compared to baseline. In the Asthma Control Test scoring, all three groups improved over the course of the 12 weeks, though more so (“significantly higher,” no P values given in the text) in the black seed groups. No adverse effects were mentioned in the study.
This is an interesting, ambitious, and multifaceted study, venturing an herbal medicine into the realm of asthma, not a common territory for adjunctive therapies. Yes, this effort might have been improved with stricter methodology (double-blind, greater numbers, etc.), but the quantitative results provided still allow for some commentary. Did this herbal medicine make a significant clinical difference for these people with mild-moderate persistent asthma? It’s difficult to say, as most of the spirometry parameters and lab tests were equivocal between the three groups. It would have been useful to see a justification for the herbal medicine form and dosing chosen in this study. A superficial review of other studies for other conditions reveals a variety of doses and forms, including vapors, oils, and decoctions, so it is possible that insufficient dosing or incorrect plant form is one explanation for the minimal performance of black seed in this trial. Also, before recommending this therapy as an adjunctive treatment, solid safety data should be provided; before exploring this “nudge” toward clinical benefit, as seen in this study, we would need to be assured of a lack of adverse effects. Overall, black seed for asthma may have some slight potential benefit, and it fits with some prior basic science, but this study alone is not sufficient to propel this plant to the top of the asthma treatment list.
REFERENCES
- Ijaz H, Tulain UR, Qureshi J, et al. Nigella sativa (prophetic medicine): A review. Pak J Pharm Sci 2017;30:229-234.
- Al Asoom LI. Coronary angiogenic effect of long-term administration of Nigella sativa. BMC Comp Altern Med 2017;17:308.
