Evidence Level
Spirulina has a moderate evidence base, anchored by several meta-analyses and systematic reviews. Huang et al. (2016) pooled 12 RCTs and found consistent LDL cholesterol reductions (~16%) and triglyceride improvements. Phycocyanin, the primary bioactive compound, has been extensively studied for its selective COX-2 inhibition and antioxidant properties (Romay et al., 2003). Immune modulation research by Selmi et al. (2011) demonstrated enhanced NK cell activity and cytokine production. For allergic rhinitis, Cingi et al. (2008) published a well-designed double-blind RCT showing significant symptom reduction at 2g/day. Blood sugar effects have been explored in smaller trials (Ou et al., 2013) with promising but preliminary results in type 2 diabetes. The main limitations are relatively small sample sizes across trials and heterogeneity in spirulina preparations. Most research uses Arthrospira platensis strains, and contamination remains a quality concern for non-certified products.