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

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. 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. 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. 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. 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.