Spirulina Supplementation and Obesity Related Metabolic Disorders: A Systematic Review and Meta-Analysis of Randomized Controlled Clinical Trials

Abstract

Background: Spirulina contains Phycobiliproteins such as C-phycocyanin and allophycocyanin, recognized as bioactive compounds, which have antioxidant, anti-inflammatory, hypolipidemic and hypoglycemic effects. Objective: To systematically evaluate the effects of spirulina on serum lipids concentrations, fasting glucose, anthropometric measures, and anti-inflammatory markers in adults with obesity or diabetes mellitus. Methods: Scopus, Embase, Pubmed, Web of Science, and Cochrane Library databases were searched to retrieve randomized controlled trials (RCTs) with control or placebo groups of spirulina supplementation on adults with obesity, and diabetes or hypertriglyceridemia. We performed random-effects meta-analyses which were described as mean differences (MD) with 95% confidence intervals (CI). The risk of bias (RoB) was assessed with the Cochrane RoB 2.0 tool. Results: We found 7 RCTs (n=338). Spirulina supplementation significantly reduced total cholesterol (MD -11.83 mg/dL; 95% CI -20.56, -3.10) and triglycerides (MD -15.34 mg/dL; 95% CI -29.76, -0.91) levels. However, LDL (MD -7.80 mg/dL; 95% CI -16.94, 1.33), HDL (MD 0.73 mg/dL; 95% CI -2.49, 3.94), fasting blood glucose (MD -3.38 mg/dL; 95% CI -9.88, 3.12) and HbA1c (MD -0.27%; 95% CI -0.94, 0.39) were non-significantly reduced. Furthermore, insulin (MD: 8.79 pmol/L; 95% CI -26.65, 9.06), weight (MD - 1.81 Kg; 95% CI -7.31, 3.69), body mass index (MD -0.63 Kg/m2; 95% CI -1.98, - 0.72), and waist circumference (MD -0.83 cm; 95% CI -4.87, 3.21) showed non-significant decreases. Conclusion: We found significant effects of spirulina on reducing total cholesterol and triglycerides levels. The inclusion of spirulina as an adjuvant treatment may benefit patients with diabetes, hypertriglyceridemia, overweight or obesity.