Effects of Rice Bran Supplementation on Metabolic Syndrome-Related Parameters: A Systematic Review and Meta-Analysis

Rice bran, a fiber-rich source of bioactive compounds, has gained attention for its potential health benefits, yet its effects on metabolic syndrome (MetS) remain unclear. This study aimed to evaluate the impact of rice bran consumption on anthropometric measures, blood pressure, glycemic control, and lipid profiles in individuals with MetS. A systematic search of PubMed/Medline, Scopus, Cochrane Library, and Embase was conducted up to 30 January 2025, to identify randomized controlled trials (RCTs) assessing rice bran supplementation. Twenty-six RCTs involving 1255 participants (642 in rice bran groups, 613 in controls) were included in the meta-analysis. Weighted mean differences (WMDs) with corresponding p values were calculated. Rice bran significantly reduced systolic blood pressure (WMD: -3.336 mmHg; p = 0.0006), diastolic blood pressure (WMD: -3.145 mmHg; p = 0.015), and HbA1c (WMD: -0.199%; p = 0.003). Lipid profiles improved, with reductions in total cholesterol (WMD: -13.594 mg/dL; p < 0.0001) and LDL cholesterol (WMD: -14.580 mg/dL; p < 0.0001), and an increase in HDL cholesterol (WMD: 3.074 mg/dL; p = 0.007). These findings suggest rice bran supplementation may be a promising natural dietary strategy for managing and preventing MetS.