Farzaneh E, Nia FR, Mehrtash M, Mirmoeini FS, Jalilvand M. The effects of 8-week Nigella sativa supplementation and aerobic training on lipid profile and VO₂ max in sedentary overweight females. Int J Prev Med. February 2014;5(2):210-216.

Being overweight or obese is a risk factor for a host of metabolic illnesses and disorders. Exercise is one of the most widespread recommendations to alleviate both obesity and the risks to cardiovascular health. Nigella (Nigella sativa) seeds are used traditionally in Asia and the Middle and Far East to treat obesity, hypertension, and diabetes, among other uses. In animals, nigella seeds have been reported to decrease lipids, specifically triglycerides, total cholesterol, and low-density lipoprotein (LDL) cholesterol. This randomized, double-blind, placebo-controlled trial with sedentary, overweight women tested the effects of nigella consumption along with aerobic exercise on lipids and maximal oxygen consumption (VO_2max).   

This study enrolled 20 females with an average age of 34.31 ± 7.9 years and average body mass index (BMI) of ≥ 25 kg/m², with a sedentary lifestyle of 2 years or more, and triglyceride concentrations of over 200 mg/dl. Those taking medications for lipids in the previous 8 weeks; who were pregnant, smoking, or lactating; who had diabetes or cardiovascular, liver, or kidney disease, or thyroid problems or myopathy (abnormal function of muscle fibers) were excluded. Subjects were randomly assigned into groups taking either nigella capsules or a placebo, with 10 subjects per group. Nigella seeds (source not noted) were powdered and placed into capsules of 500 ± 10 mg for a daily dose of 2 g (2 capsules in the morning and afternoon before meals). Placebo was not described. Subjects were instructed not to alter their diets or activity level.

The exercise regimen consisted of 10 minutes of slow running, 10 minutes of stretching and warmup, 30 minutes of aerobic exercise, and 10 minutes of cool down. The exercise regimen was conducted 3 days per week for 8 weeks at home, and 60-70% of the target heart rate (a factor of maximum and resting heart rate for subjects' age) determined the exercise intensity. Resting heart rate was taken either immediately after subjects' awakening or after a period of 10 minutes of resting in a prone position by the subject herself. VO_2max was determined by a formula factoring in subjects' weight, age, time, and heart rate during a "brisk" walk of 1 mile. VO_2max was determined and blood was collected at baseline and end of the study.

In total, 8 subjects in the nigella group and 8 subjects in the placebo group completed the study. Subjects were dropped from the study for deviating from their standard exercise routines or noncompliance with the nigella or placebo supplement (n=2 for each group). Baseline parameters were not different between groups. After 8 weeks of treatment, total cholesterol and triglycerides were significantly reduced in the nigella group as compared to baseline (210.88 ± 31.50 mg/dl vs. 221.50 ± 31.34 mg/dl, P<0.002, and 154.50 ± 16.18 mg/dl vs. 167.88 ± 18.61 mg/dl, P<0.000, respectively) [Note: P values in the abstract and tables differ. The P values shown reflect those found in the tables.], HDL was increased (45.62 ± 10.02 mg/dl vs. 48.25 ± 10.04 mg/dl, P<0.004), and LDL cholesterol concentrations and BMI were also decreased (113.12 ± 11.78 mg/dl vs. 119.10 ± 11.96 mg/dl, P<0.000, and 24.69 ± 0.75 kg/m² vs. 25.39 ± 0.75 kg/m², P<0.001, respectively). VO_2max was also significantly elevated in those consuming nigella compared to baseline (35.66 ± 5.03 kg/ml/min vs. 35.66 ± 5.03 kg/ml/min, P<0.008).

In subjects in the placebo group, total cholesterol and LDL cholesterol were also significantly decreased as compared to baseline (220 ± 15.92 mg/dl vs. 232.75 ± 12.85 mg/dl, P<0.000, and 109.88 ± 12.01 mg/dl vs. 120.5 ± 10.39 mg/dl, P<0.001, respectively). VO_2max was also significantly increased in this group as compared to baseline (34.81 ± 2.66 kg/ml/min vs. 34.19 ± 2.47 kg/ml/min, P<0.002). 

In this study, all subjects' VO_2max, total cholesterol, and LDL cholesterol concentrations improved. In those consuming nigella supplements, triglyceride and HDL concentrations and BMI were additionally improved, suggesting that this botanical may have effects on lipid profile and weight reduction along with an exercise program in overweight or obese populations.