Black Cumin and Reduced Low-Density Lipoprotein Level

Across 3 meta-analyses, 2 reported beneficial effects of black cumin (Nigella sativa) supplementation on low-density lipoprotein cholesterol (LDL-C), with effect sizes ranging from moderate to large. The largest and highest-quality study (82 RCTs, 5026 participants) found moderate beneficial effects, while a second meta-analysis reported a large effect (SMD: -2.45). The third study showed neutral effects in type 2 diabetes patients. Doses varied widely (200–4600 mg/day), and median study duration was only 7 days, which is too short to draw conclusions about long-term effects.

• Effective dose range: 200 to 4600 mg/day
• Studied populations: general adult participants, type 2 diabetes patients (null effect in this subgroup)

Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. The median study duration was only 7 days (reported in 1 of 3 studies), which may be insufficient for lipid changes to manifest; most lipid-lowering trials last at least 8–12 weeks. One study focused on type 2 diabetes patients found neutral effects, suggesting benefits may not be consistent across all clinical subgroups. Doses varied widely, and no form data was available to assess whether different preparations (e.g., oil vs. powder) differ in efficacy.