Rice Bran Oil May Improve Glycemic Control, Alleviate Lipid Peroxidation and Improve Antioxidant Defense in Overweight/Obese Adults with Metabolic Syndrome

Introduction: We previously documented the beneficial effects of rice bran oil (RBO) on cardiac function, and on atherogenic cardiometabolic factors of men with coronary artery disease. Hence, in the current trial, we aimed at extending these findings by exploring the effects of this healthy oil on the metabolic profile, novel insulin resistance surrogate markers, lipid peroxidation, and antioxidant status of overweight/obese men and women with metabolic syndrome (MetSyn).

Methods: A total of 50 overweight/obese adults (mean body mass index (BMI) = 31.08 kg/m2) with at least 3 MetSyn components were randomly allocated to either a control group, who received standard diet plan, or intervention, who were additionally supplemented with 30g/d of RBO for 8 weeks. BMI, MetSyn components, metabolic score for insulin resistance (METS-IR), triglyceride-glucose–BMI index (TyG-BMI), malondialdehyde (MDA), total antioxidant capacity (TAC), and plasma polyphenols levels were measured before and after this open-label trial.

Results: Analysis of covariance (ANCOVA) adjusted for baseline values revealed that compared to the patients who only received the standard diet plan, those who were additionally supplemented with 30g/d RBO demonstrated significantly reduced total cholesterol (P-value =0.005; effect size(ES):-0.92), LDL-cholesterol (P-value=0.048; ES:-0.62), fasting blood sugar (P-value =0.014; ES:-0.77), MDA (P-value =0.002; ES: -1.01), METS-IR (P-value<0.001; ES: -1.24); and TyG-BMI (P-value=0.007; ES:-0.85) after 8 weeks. Additionally, RBO consumption resulted in significantly higher levels of HDL-cholesterol (P-value=0.004; ES:0.94) and TAC (P-value<0.0001; ES:2.05). However, no significant changes were noted regarding BMI, waist circumference, serum triglyceride, plasma polyphenols, and blood pressure.

Conclusion: Dietary supplementation with RBO in addition to standard diet could be an effective complementary option for MetSyn, considering its hypocholesterolemic, antihyperglycemic, and antioxidative effects, and alleviating lipid peroxidation in these with patients.