The beneficial effects of Chlorella vulgaris supplementation on health-related indices in patients with non-alcoholic fatty liver disease: a GRADE-assessed systematic review and meta-analysis

This systematic review and meta-analysis aimed to assess the impact of Chlorella vulgaris (C. vulgaris) consumption on cardiovascular disease risk factors in patients with non-alcoholic fatty liver disease (NAFLD). Relevant research was identified through electronic searches of databases up to September 19, 2025. Study quality was assessed using the Cochrane risk-of-bias tool (ROB 2). Seven trials, all conducted in Iran, with interventions ranging from 8 to 12 weeks and involving 375 participants, were included. C. vulgaris supplementation demonstrated significant reductions in weight (Weighted Mean Difference [WMD]= -1.62, 95% Confidence Interval [CI]: -2.24, -1.00), fasting blood sugar (FBS) (WMD= -6.25, 95% CI: -9.02, -3.47), high-sensitivity C-reactive protein (hs-CRP) (WMD= -1.02, 95% CI: -1.84, -0.19), low-density lipoprotein cholesterol (LDL-C) (WMD= -6.45, 95% CI: -12.25, -0.64), total cholesterol (TC) (WMD= -7.18, 95% CI: -10.84, -3.52), alkaline phosphatase (ALP) (WMD= -14.84, 95% CI: -27.81, -1.87), and aspartate aminotransferase (AST) (WMD= -4.99, 95% CI: -7.26, -2.71). This meta-analysis demonstrates that C. vulgaris supplementation significantly improves liver function, glycemic control, and lipid profiles in patients with NAFLD. However, all included studies were conducted in Iran, limiting the generalizability of these findings, and the certainty of evidence was rated as very low due to risk of bias, indicating that the results should be interpreted with caution.