Supplementing the standard diet with brown rice bran powder might effectively improve the metabolic syndrome characteristics and antioxidant status: an open label randomized controlled trial

Purpose: This study explores the impact of brown rice bran powder (BRBP), known for its beneficial components, such as dietary fiber and gamma-oryzanol, on individuals suffering from metabolic syndrome (MetS). Subjects/Methods: In this eight-week open-label controlled trial, fifty participants with MetS were randomly assigned to either a control group, which received a standard diet (SDiet), or an intervention group, which incorporated 15 grams of BRBP daily into their diet. Demographic, anthropometric and clinical data were collected, and blood samples were taken to assess metabolic factors and antioxidant enzyme activities. Additionally, the participants completed the gastrointestinal symptom rating scale questionnaire. Results: Analysis of covariance controlled for the baseline levels and medication consumptions revealed that postthis trial, compared to the controls, patients who received BRBP showed significant reductions in BMI (P-value = 0.001; effect size (ES): -1.13), waist circumference (P-value < 0.001; ES: -1.28), total-cholesterol (P-value = 0.028; ES: -0.74), LDL-cholesterol (P-value = 0.002; ES: -0.86), blood sugar (P-value = 0.013; ES: -0.82), as well as triglyceride glucose (TyG)-BMI index (as a marker of insulin resistance) (P-value < 0.001; ES: -1.35). Further, BRBP resulted in significant improvements in antioxidant enzyme activities, including glutathione peroxidase (P-value = 0.010; ES: 0.86), superoxide dismutase serum activities (P-value = 0.021; ES: 0.78), and constipation rate (P-value = 0.018; ES: -0.85) compared to SDiet alone. However, no significant changes were found regarding levels of triglyceride, HDL-cholesterol, glutathione, catalase and blood pressure after the trial. Conclusion: The findings of this trial support the weight-reducing, hypocholestrolemic, anti-hyperglycemic, and antioxidative effects of adding BRBP to SDiet that is prescribed for MetS patients.