Black Cumin Seed - Nigella Sativa


Clinical Information and Studies


Here’s a structured list of human clinical trials (plus a few key meta-analyses) that back up the main health areas we talked about for black cumin (Nigella sativa): cardiometabolic health, blood pressure, blood sugar, and asthma/respiratory function.

1. Cholesterol & Lipid Profile

1.1 Menopausal women with high lipids

“A randomized controlled trial on hypolipidemic effects of Nigella sativa in menopausal women” – Ibrahim et al., 2014 (BioMed Central)

  • Design: Randomized, placebo-controlled clinical trial
  • Participants: Menopausal women with dyslipidemia
  • Intervention: Nigella sativa capsules (powdered seed) daily vs placebo for 2 months
  • Main findings: Significant reductions in total cholesterol, LDL, triglycerides, and an increase in HDL compared with placebo. Effects started to fade 1 month after stopping supplementation.

1.2 Type 2 diabetes – lipids + glucose

“Nigella sativa oil affects glucose metabolism and lipid concentrations in patients with type 2 diabetes” – Heshmati et al., 2015 (ScienceDirect)

  • Design: Randomized, double-blind, placebo-controlled trial
  • Participants: Patients with type 2 diabetes
  • Intervention: N. sativa oil (in capsules) vs placebo for 8 weeks
  • Main findings: Improved fasting blood sugar, HbA1c, and lipid profile (lower total cholesterol and triglycerides) vs placebo.

1.3 Long-term cardiometabolic effects in T2D

“Effect of Nigella sativa supplementation over a one-year period in patients with type 2 diabetes” – Badar et al., 2017 (annsaudimed.net)

  • Design: Randomized clinical trial, 1-year duration
  • Participants: Patients with type 2 diabetes on oral hypoglycemic drugs
  • Intervention: N. sativa capsules vs control
  • Main findings: Long-term supplementation significantly lowered total cholesterol, LDL, and fasting blood sugar, and improved some markers of oxidative stress.

1.4 Cardiometabolic risk factors

“Effect of Nigella sativa oil extract on cardiometabolic risk factors in people with type 2 diabetes” – Hadi et al., 2021 (PubMed)

  • Design: Randomized, controlled clinical trial
  • Participants: Adults with type 2 diabetes
  • Intervention: N. sativa oil extract vs placebo for several weeks
  • Main findings: Improvement in multiple cardiometabolic risk markers, including lipid parameters and some inflammatory markers, suggesting supportive effects for heart and metabolic health.

1.5 Lipid profile across multiple RCTs (meta-analysis)

Sahebkar et al., 2016 – Meta-analysis of RCTs on plasma lipids (PubMed)

  • Design: Meta-analysis of randomized controlled trials on Nigella sativa seed and oil
  • Main findings: Nigella sativa significantly reduced total cholesterol, LDL-C, and triglycerides, and increased HDL-C (especially with seed powder).

2. Blood Pressure (Hypertension)

2.1 Healthy volunteers – seed oil

“Blood pressure lowering effect of Nigella sativa L. seed oil in healthy volunteers” – Fallah Huseini et al., 2013 (PubMed)

  • Design: Randomized, double-blind, placebo-controlled trial
  • Participants: Healthy adults
  • Intervention: N. sativa seed oil capsules vs placebo for 8 weeks
  • Main findings: Significant reductions in both systolic and diastolic blood pressure compared with placebo, with no serious adverse events.

2.2 Stage 1 hypertension

“Phytotherapy Nigella sativa lowers blood pressure in patients with stage 1 hypertension” – Saumi et al., 2015 (abstract) (Lippincott Journals)

  • Design: Clinical trial in patients with stage 1 hypertension
  • Participants: Adults with mild hypertension
  • Intervention: N. sativa supplementation vs control for 8 weeks
  • Main findings: Blood pressure decreased and there were beneficial changes in lipid profile and blood sugar in the Nigella group.

2.3 Blood pressure – pooled RCTs

Kavyani et al., 2023 – Systematic review & meta-analysis of randomized clinical trials (PubMed)

  • Design: Meta-analysis of RCTs evaluating N. sativa on blood pressure
  • Main findings: Nigella sativa supplementation reduced systolic blood pressure more than diastolic, and oil preparations tended to be more effective than powder.

3. Blood Sugar & Diabetes

3.1 Long-term glycemic control

“Nigella sativa improves glycemic control and ameliorates oxidative stress in type 2 diabetic patients” – Kaatabi et al., 2015 (PLOS ONE) (PLOS)

  • Design: Randomized, double-blind, placebo-controlled trial
  • Participants: Patients with type 2 diabetes on standard oral drugs
  • Intervention: N. sativa capsules (seed powder) vs placebo for 1 year
  • Main findings: Significant improvements in fasting blood glucose, HbA1c, insulin resistance indices, and antioxidant markers, supporting both glycemic and antioxidant/immune claims.

3.2 Oil in T2D

Heshmati et al., 2015 trial (already above) (ScienceDirect)

  • Key relevance: Showed N. sativa oil improves both glucose metabolism and lipid profile in diabetics.

3.3 Powder in T2D (recent RCT)

“The Effect of Nigella sativa Powder on Blood Sugar and Lipid Profile in Patients with Type 2 Diabetes” – Javaheri et al. (Brieflands)

  • Design: Double-blind, randomized, controlled clinical trial
  • Participants: 80 patients with type 2 diabetes
  • Intervention: N. sativa powder vs placebo, added to standard therapy
  • Main findings: Significant improvements in fasting blood sugar, HbA1c, and lipid parameters in the Nigella group.

3.4 Overview of antidiabetic evidence

“Antidiabetic Activity of Nigella sativa (Black Seeds) and Its Active Constituent Thymoquinone” – Maideen, 2021 (review) (PMC)

  • Summarizes multiple clinical and animal studies showing improved glycemic control, supporting its use as an adjunct (not replacement) to conventional diabetes treatment.

4. Asthma & Respiratory Health

4.1 Partly controlled asthma – seed supplementation

“Effect of Nigella sativa supplementation on lung function and inflammatory mediators in partly controlled asthma” – Salem et al., 2017 (annsaudimed.net)

  • Design: Randomized, controlled trial
  • Participants: Adults with partly controlled asthma
  • Intervention: N. sativa capsules plus usual inhaler therapy vs placebo plus usual therapy
  • Main findings: Improved lung function (FEV₁) and reduced inflammatory markers compared with control, supporting anti-inflammatory and respiratory benefits.

4.2 Asthma control with seed oil

“Nigella sativa oil supplementation improves asthma control” – Koshak et al., 2017 (PubMed)

  • Design: Randomized, double-blind, placebo-controlled trial
  • Participants: Adults with asthma
  • Intervention: N. sativa oil capsules vs placebo
  • Main findings: Significant improvement in Asthma Control Test (ACT) scores, with a trend toward better pulmonary function and normalization of blood eosinophil counts, indicating anti-inflammatory action.

4.3 Anti-inflammatory effects in asthma

Ikhsan et al., 2018 – “Nigella sativa as an anti-inflammatory agent in asthma” (BioMed Central)

  • Design: Single-blind randomized clinical trial
  • Participants: Partly controlled asthma patients
  • Intervention: N. sativa supplementation added to inhaled maintenance therapy
  • Main findings: Increased ACT scores, improved lung function, and reduced IgE levels, reinforcing the anti-inflammatory/immunomodulatory role.

4.4 Meta-analyses of asthma trials

  • Han et al., 2020 & He et al., 2020 – Meta-analyses on Nigella sativa in asthma (PMC)

    • Main findings: Across several RCTs, N. sativa supplementation significantly improved ACT scores and FEV₁, although effects on peak expiratory flow were less clear.

5. Obesity, Appetite & Metabolic Syndrome

5.1 Overweight/obesity and appetite

Recent RCT on black cumin and obesity-related outcomes (2025) (News-Medical)

  • Design: Randomized trial (8 weeks) in overweight/obese adults (BMI > 25)
  • Participants: 42 adults, 22 in treatment group, 20 in control
  • Intervention: Black cumin seed supplementation vs control
  • Main findings: Improved appetite regulation and lipid profile, supporting its role in weight-related metabolic health (though more and larger studies are still needed).

6. Where Evidence Is Still Limited

  • Digestive health: Most support is traditional (bloating, gas, digestion). There are fewer high-quality RCTs that look specifically at constipation or IBS using Nigella sativa alone.
  • Skin and hair: Some small or cosmetic-industry studies exist on black seed oil creams or hair products, but robust, large RCTs are limited. Evidence is suggestive rather than definitive.