Effects of Glucomannan on Cardiometabolic Parameters in Adults With Insulin Resistance-Related Conditions: A Systematic Review and Dose-Response Meta-Analysis.

Abstract

Inconsistent findings regarding the impacts of glucomannan intake on health-related outcomes have been reported in different health conditions. Therefore, this meta-analysis aimed to assess the impacts of glucomannan consumption on cardiometabolic parameters in adults with insulin resistance-related conditions. PubMed, Scopus, and Web of Science databases were comprehensively searched up to March 2025 to find eligible studies. Overall effect sizes were calculated according to the random-effects model and expressed as weighted mean differences (WMDs) with 95% confidence intervals (95% CIs). Heterogeneity among the included trials was assessed by performing Cochran's Q test and measured by the I ² statistic. Eleven eligible trials were included in this review. Meta-analysis revealed that glucomannan significantly reduced fasting blood glucose (FBG) (WMD: -7.02 mg/dL, 95% CI: -13.56, -0.49, p = 0.04); however, this effect was no longer statistically significant under the alternative method for the correlation assumption. Meanwhile, the effects of glucomannan intake on lipid profile, obesity indices, and blood pressure were not significant. Exploratory subgroup analyses suggested reductions in SBP, total cholesterol, and low-density lipoprotein cholesterol (LDL-C) in studies using higher glucomannan doses (> 3000 mg/day) or shorter intervention durations (≤ 4 weeks); however, these subgroup findings should be interpreted cautiously. This meta-analysis suggests that glucomannan intake may reduce FBG levels in insulin-resistance-related conditions. However, due to a limited number of eligible trials, more high-quality randomized controlled trials are needed to reach firm conclusions regarding the effectiveness of this intervention in different health conditions and to explore optimal dosage and duration for each therapeutic purpose.