Spirulina’s impacts on cardiovascular health: Insights from a systematic meta-analysis of RCT

INTRODUCTION: CVDs are considered the major public health concern and mortality in the world. Common treatments have some side effects and require low-risk treatments, such as herbal medicine. Spirulina is a filamentous microalga that has improved cardiometabolic parameters. METHODS: Systematic searches were conducted in Scopus, ISI Web of Science, and PubMed/Medline databases up to 20 January 2025 to identify RCTs based on the PRISMA checklist and PICOS criteria (People > 18 years, Intervention: spirulina, Comparison: placebo /control, Outcomes: TG, TC, LDL-C, HDL-C, FBG, HbA1c, insulin, HOMA-IR, SBP, DBP, BMI, weight, hs-CRP, IL-6, TNF-α, and Study: RCTs). Meta- analysis was utilized by random-effects models, and the GRADE criteria ensured the certainty of results. RESULT: The results of 35 trials (45 effect sizes) show that spirulina intake improved glucose homeostasis (FBG; WMD: -5.51 (mg/dl); P = 0.001, HOMA-IR; WMD: -0.68; P < 0.001, and insulin; WMD: -0.86 (ng/ml); P = 0.002), decreased dyslipidemia (TG; WMD: -14.75 (mg/dl); P < 0.001, TC: WMD: -11.5 (mg/dl); P < 0.001, LDL-C; WMD: -7.69 (mg/dl); P < 0.001, and HDL-C; WMD: 1.9 (mg/dl); P < 0.001), decreased blood pressure (SBP; WMD: -3.85 mmHg, P = 0.002, and DBP; WMD: -3.09 mmHg, P < 0.001), reduced anthropometric indexes (weight; WMD: -1.78 kg; P = 0.003, and BMI; WMD: -0.58 kg/m²; P = 0.001), and decreased inflammation (TNF-α; WMD: -0.46 pg/ml; P = 0.01, IL-6; WMD: -0.58 pg/ml; P < 0.001, and hs-CRP; WMD: -0.86 mg/L; P = 0.002). Based on GRADE analysis, LDL-C, FBG, and HbA1c had of low quality, while the outcome for weight was of high quality. Furthermore, other parameters had moderate-quality outcomes. CONCLUSION: This study demonstrates that spirulina supplementation effectively reduces the risk of CVD in adults by improving glucose homeostasis, dyslipidemia, blood pressure, anthropometric indexes, and inflammation. So, intake of spirulina is an adjunct or complementary to improve cardiometabolic profiles. TRIAL REGISTRATION: PROSPERO registration cod: (CRD42024626090).