Black Seed Oil

Razmpoosh et al. (2024) report on a crossover design randomized controlled trial where they gave 2 g/day of Nigella sativa oil or placebo to 46 overweight and obese women ages 25 to 55 for eight weeks, with four weeks of washout before the groups switched.  The cold-pressed Nigella sativa oil with thymoquinone concentration of 1.1% was provided in capsules, and paraffin oil was used in the placebo capsules.  The capsules were taken with lunch and dinner.  Each participant was asked to follow a diet plan throughout the eight weeks that had been calculated based on their individual body weight to prevent calorie deficit, providing 55% carbohydrates, 30% fat, and 1.2 g/kg body weight of protein.  They were asked to maintain their normal level of physical activity.  Serum leptin was assessed by the enzyme-linked immunoassay (ELISA) method.  Serum leptin levels decreased significantly by a mean of 3.1 ng/mL in the intervention group.  The authors considered this to be a clinically significant effect based on a study by Kempf et al. (2022) where overweight and obese adults whose serum leptin decreased by 3.3 mg/mL in the first month of a high-protein low-glycemic meal replacement intervention were more likely to lose weight over the 12 months of the study. 

 

Kempf et al. (2022) explain that early studies such as Heymsfield et al. (1999) attempted to control appetite in n obese people by giving them exogenous leptin, but this didn’t work, leading to the hypothesis of leptin resistance.  This explains why, in people with obesity, lowering serum leptin levels is able to restore the ability of leptin to regulate appetite.  Kempf et al. (2022) found that weight loss over 12 months correlated to a greater degree with the decrease in leptin during the first month of the intervention than it did with the participants’ baseline leptin values.  With this in mind, I would recommend Nigella sativa oil to overweight clients who report struggling to control their appetite in order to lose weight, without needing to see a serum leptin test.  This is not to say that the test lacks validity; Wadden et al. (1998) report that it has a variance of only 3.4% within the assay, and 3.6% between assays.  In addition it was found to correlate with BMI and also inflammatory markers (Razmpoosh et al., 2024).  It just might not be necessary to measure levels before recommending this intervention. 

 

References:

 

Heymsfield, S. B., Greenberg, A. S., Fujioka, K., Dixon, R. M., Kushner, R., Hunt, T., Lubina, J. A., Patane, J., Self, B., Hunt, P., & McCamish, M. (1999). Recombinant leptin for weight loss in obese and lean adults: a randomized, controlled, dose-escalation trial. JAMA, 282(16), 1568–1575. 

 

Kempf, K., Röhling, M., Banzer, W., Braumann, K. M., Halle, M., Schaller, N., McCarthy, D., Predel, H. G., Schenkenberger, I., Tan, S., Toplak, H., Martin, S., Berg, A., & Acoorh Study Group. (2022). Early and Strong Leptin Reduction Is Predictive for Long-Term Weight Loss during High-Protein, Low-Glycaemic Meal Replacement-A Subanalysis of the Randomised-Controlled ACOORH Trial. Nutrients, 14(12). 

 

Razmpoosh, E., Safi, S., Mazaheri, M., Khalesi, S., Nazari, M., Mirmiran, P., & Nadjarzadeh, A. (2024). A crossover randomized controlled trial examining the effects of black seed (Nigella sativa) supplementation on IL-1β, IL-6 and leptin, and insulin parameters in overweight and obese women. BMC Complementary Medicine and Therapies, 24(1), 22. 

Wadden, T. A., Considine, R. V., Foster, G. D., Anderson, D. A., Sarwer, D. B., & Caro, J. S. (1998). Short- and long-term changes in serum leptin dieting obese women: effects of caloric restriction and weight loss. The Journal of Clinical Endocrinology and Metabolism, 83(1), 214–218.