Spirulina Supplementation Can Reduce Serum Levels of C-Reactive Protein: A Systematic Review and Meta-Analysis on Randomized Clinical Trials.

Spirulina supplementation significantly reduced serum CRP concentrations compared with placebo.

• Weighted mean difference (WMD): -0.09 mg/L; 95% confidence interval (CI): -0.16 to -0.02
• Eight RCTs met inclusion criteria for the meta-analysis
• Pooled effects were calculated using the DerSimonian and Laird random-effects model
• Heterogeneity for CRP was reported as significant

Spirulina supplementation caused a non-significant reduction in TNF-α concentration.

• WMD: -0.43 pg/mL; 95% CI: -1.44 to 0.59
• The confidence interval crossed zero, indicating a non-statistically significant effect
• Heterogeneity concerning TNF-α was significant

Spirulina supplementation caused a non-significant reduction in IL-6 concentration.

• WMD: -0.44 pg/mL; 95% CI: -0.98 to 0.10
• The confidence interval crossed zero, indicating a non-statistically significant effect
• Heterogeneity concerning IL-6 was significant

Eight randomized clinical trials met the inclusion criteria for the systematic review and meta-analysis.

• Relevant RCTs were identified through searches of Cochrane Library, ClinicalTrials.gov, ISI Web of Science, Scopus, and PubMed up to August 2025
• Participants were adults aged 18 years and older
• Administered dosages of Spirulina varied from 1 g/day to 8 g/day
• Intervention durations spanned 3 to 16 weeks
• Study registered in PROSPERO (CRD42024606496)

Significant statistical heterogeneity was observed across all inflammatory mediators examined.

• Heterogeneity was assessed using I-squared statistics and Cochran's Q test
• Significant heterogeneity was found for CRP, TNF-α, and IL-6 outcomes
• The authors conclude that owing to the significant heterogeneity, further high-quality RCTs are needed to confirm these beneficial effects