Endocrinology · Medical Literature
Nigella sativa (Black Seed) Oil Alleviates the Serum Levels of IL-6 and Insulin in Patients With Polycystic Ovary Syndrome.
Abstract
Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder that affects 5%-10% of women of reproductive age. Supplements with potential anti-inflammatory properties, such as Nigella sativa oil, have been proposed as adjunctive therapies that may improve selected metabolic and inflammatory features of PCOS. This study investigated the effect of N. sativa oil on serum levels of IL-6 and insulin in patients with polycystic ovary syndrome. This study was a randomized, double-blind, placebo-controlled clinical trial conducted on 60 PCOS patients. Patients received either N. sativa oil supplementation (1000 mg daily) or placebo for 12 weeks. Intermenstrual interval, menstrual duration, fasting blood glucose, insulin, insulin resistance, and serum IL-6 levels were measured. Sixty women with PCOS were randomized equally to the intervention and placebo groups. After baseline adjustment, serum IL-6 (adjusted mean difference -4.21; 95% CI -6.34 to -2.08; p < 0.001) and fasting blood glucose (adjusted mean difference -8.16 mg/dL; 95% CI -12.73 to -3.58; p < 0.001) were significantly lower in the N. sativa group than in the placebo group. No significant between-group differences were observed for fasting insulin, HOMA-IR, QUICKI, luteinizing hormone, or total testosterone. The intermenstrual interval was significantly shorter in the intervention group, whereas menstrual duration and other clinical manifestations showed no significant between-group differences. Twelve weeks of N. sativa oil supplementation were associated with significant improvements in inflammatory status and fasting blood glucose compared with placebo after baseline adjustment. However, no significant between-group effects were observed for insulin resistance indices or hormonal outcomes. These findings support the potential adjunctive role of N. sativa oil in PCOS while highlighting the need for larger adequately powered clinical trials.
Clinical relevance
Does 12 weeks of Nigella sativa (black seed) oil supplementation (1000 mg daily) reduce serum IL-6 and insulin levels compared to placebo in women with polycystic ovary syndrome? __SNAPSHOT__ {"studyDesign":"Randomized, double-blind, placebo-controlled clinical trial","setting":"Not reported (country/institution not specified in abstract)","sampleSize":"n=60 (intervention: 30, control: 30)","population":"Women with a confirmed diagnosis of polycystic ovary syndrome (PCOS); reproductive-age females. Further inclusion/exclusion criteria not reported in the available abstract.","intervention":"Nigella sativa (black seed) oil 1000 mg orally once daily for 12 weeks","comparator":"Matched placebo for 12 weeks","primaryOutcome":"Serum IL-6 level and serum insulin level (as stated in the study title and abstract; the abstract also reports fasting blood glucose, insulin resistance, intermenstrual interval, and menstrual duration as measured outcomes; formal pre-specified primary vs. secondary designations are not clearly delineated in the available abstract)","followUp":"12 weeks","fundingSource":"Not reported"}
Key findings
After adjustment for baseline values, serum IL-6 was significantly lower in the N. sativa group compared to placebo (adjusted mean difference: −4.21 units [units not specified in abstract]; 95% CI: −6.34 to −2.08; p < 0.001). Fasting blood glucose was also significantly lower in the N. sativa group (adjusted mean difference: −8.16 mg/dL; 95% CI: −12.73 to −3.58; p < 0.001). The abstract is truncated and does not report the complete results for serum insulin, insulin resistance (HOMA-IR or equivalent), intermenstrual interval, or menstrual duration. Absolute event rates for adverse outcomes, NNT, and NNH are not calculable from the available data. No adverse event data are reported in the available abstract.
Practice implications
This small, 12-week RCT suggests that N. sativa oil 1000 mg/day may modestly reduce serum IL-6 and fasting blood glucose in women with PCOS; however, several critical limitations constrain interpretation. The sample size of 60 is small, limiting both power and generalizability. The abstract is truncated, meaning results for insulin and insulin resistance — outcomes central to the study's stated aims — are not available for review; findings must therefore be considered incomplete. The clinical units for IL-6 are not specified, making it impossible to contextualize the magnitude of the −4.21 change against established clinically meaningful thresholds. The glucose reduction of 8.16 mg/dL, while statistically significant, is of uncertain clinical importance in the absence of baseline glucose values, HbA1c data, or information on whether participants were normoglycemic or dysglycemic at enrollment. The PCOS population studied appears to be adult women of reproductive age, but BMI, disease severity, concomitant medications (e.g., metformin, oral contraceptives), and dietary co-interventions are not reported. Whether these findings are generalizable across PCOS phenotypes (e.g., lean vs. obese, hyperandrogenic vs. normoandrogenic) cannot be determined. Practice should not change on the basis of this single small trial; confirmation in larger, adequately powered trials with longer follow-up and standardized PCOS phenotyping is required. Only the abstract was available for review, which is a significant limitation to this summary. __LIMITATIONS__ Very small sample size (n=60 total; n=30 per arm), limiting statistical power and precision of effect estimates.,Abstract is truncated; results for the key outcomes of serum insulin and insulin resistance are not reported, leaving the study's central aims incompletely addressed.,IL-6 units are not specified, preventing assessment of clinical significance of the observed change.,Baseline metabolic characteristics (BMI, HbA1c, baseline glucose, HOMA-IR), PCOS phenotype, and concomitant therapies are not reported in the available abstract.,Short follow-up duration (12 weeks) is insufficient to assess durability of effects or impact on clinically meaningful endpoints such as ovulation rates, pregnancy, or long-term metabolic outcomes.,Blinding integrity (allocation concealment, capsule matching) not described in the abstract.,Funding source not disclosed; potential conflicts of interest cannot be assessed.,Single-center or multi-center status, country of origin, and dietary standardization not reported, limiting generalizability.,Surrogate endpoints only (IL-6, glucose, insulin); no patient-important outcomes (fertility, menstrual regularity restoration, quality of life) reported in the available abstract.,Only the abstract was available; full methodological details, complete results, and safety data could not be reviewed. __BOTTOM_LINE_CATEGORY__ promising_but_preliminary __BOTTOM_LINE__ This small (n=60), 12-week double-blind RCT found that N. sativa oil 1000 mg/day significantly reduced serum IL-6 and fasting blood glucose compared to placebo in women with PCOS, but the abstract is truncated and insulin/insulin resistance results are unavailable for review. The clinical magnitude of these effects remains uncertain, and no patient-important outcomes were reported. This trial is hypothesis-generating and insufficient to support a change in clinical practice; larger, adequately powered studies with complete outcome reporting are needed before N. sativa oil can be recommended as adjunctive therapy in PCOS management.