The effect of glucomannan supplementation on lipid profile in adults: a GRADE-assessed systematic review and meta-analysis

Background Glucomannan has been studied for various health benefits, but its effects on lipid profile in adults are not well understood. This meta-analysis aims to evaluate the impact of glucomannan supplementation on serum/plasma levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), Apo B1, Apo A1, APO-B/ A1 ratio, and LDL-C/ HDL-C in adults. Methods A comprehensive search was conducted across Scopus, PubMed, Embase, and Web of Science from inception to June 2024 to identify randomized controlled trials (RCTs) assessing glucomannan supplementation on lipid profile in adults. Data were extracted and analyzed using random effects model to determine the standardized mean differences (SMDs) and 95% confidence intervals (CIs) for each biomarker. Results Glucomannan supplementation significantly decreased TC (SMD: -3.299; 95% CI: -4.955, -1.664, P < 0.001; I (2) = 95.41%, P-heterogeneity < 0.001), LDL-C (SMD: -2.993; 95% CI: -4.958, -1.028; P = 0.006; I (2) = 95.49%, P-heterogeneity < 0.001), and Apo B1 (SMD: -2.2; 95% CI: -3.58, -0.82; P = 0.01). However, glucomannan did not alter the levels of TG (SMD: -0.119; 95% CI: -1.076, 0.837, P = 0.789; I (2) = 91.63%, P-heterogeneity < 0.001), Apo A1 (SMD: -0.48; 95% CI: -6.27, 5.32; P = 0.76), APO-B/ A1 ratio (SMD: -1.15; 95% CI: -2.91, 0.61; P = 0.11), and LDL-C/ HDL-C ratio (SMD: -2.2; 95% CI: -7.28, 2.87; P = 0.2). Conclusions Glucomannan supplementation has a beneficial effect on the level of TC and LDL-C.