Effects of spirulina (Arthrospira) platensis supplementation on inflammation, physical and mental quality of life, and anthropometric measures in patients with relapsing-remitting multiple sclerosis (RRMS): a triple-blinded, randomized, placebo-controlled trial

Abstract Background Multiple sclerosis (MS) is a chronic neuroinflammatory disorder marked by demyelination and axonal damage, where oxidative stress and cytokine-mediated inflammation are key pathological factors. Spirulina, a microalga rich in phycocyanin, phenolic compounds, and omega-3 fatty acids, exhibits potent antioxidant and anti-inflammatory properties, potentially targeting these pathways. This study investigated spirulina’s impact on inflammatory biomarkers and quality of life in relapsing-remitting MS (RRMS) patients. Methods A triple-blind, placebo-controlled trial randomized 80 RRMS patients (EDSS 0–6) to receive 1 g/day spirulina (n = 40) or placebo (n = 40) for 12 weeks. Sixteen participants (20%) withdrew. Primary analysis followed the intention-to-treat (ITT) principle (N = 80) using baseline-observation-carried-forward for missing data. Serum IL-1β and IL-6 (primary outcomes) were measured by ELISA. Quality of life (MSQoL-54) and anthropometric measures were secondary outcomes. Results A linear mixed-effects model revealed that spirulina supplementation significantly reduced serum IL-1β (Estimate = − 1.07 ± 0.14, p < 0.001) and IL-6 levels (Estimate = − 2.66 ± 0.26, p < 0.001) compared to placebo. Significant improvements were also observed in health perception (Estimate = − 0.49 ± 0.12, p < 0.001), physical function (–0.37 ± 0.11, p < 0.001), role limitation–physical (–0.36 ± 0.16, p = 0.030), energy (–0.64 ± 0.15, p < 0.001), and sexual function (–1.31 ± 0.29, p < 0.001). No significant effects were found for emotional wellbeing, health distress, social function, cognitive function, sexual satisfaction, overall quality of life, or total mental health. Anthropometric analysis showed a significant weight reduction in the spirulina group versus placebo (–2.85 ± 1.13 kg, p = 0.015), while BMI reduction was borderline significant (–0.78 ± 0.41, p = 0.060). No significant changes were observed in waist circumference, waist-to-hip ratio, energy intake, or physical activity. Conclusion Spirulina supplementation significantly reduced pro-inflammatory markers and improved multiple physical and cognitive quality of life domains in patients with RRMS. Spirulina shows promise as a safe adjunct therapy in MS management, but larger trials with longer follow-up are warranted to confirm these findings and explore its clinical utility alongside DMTs. Trial registration The trial is registered with the Iranian Registry of Clinical Trials (ID IRCT2024124060794N1), with registration completed on 4 February 2024. Informed consent will be secured from each participant or their legal guardian.