Rice Bran Consumption Improves Lipid Profiles: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Area of Science:

• Nutritional Science
• Cardiovascular Health
• Dietary Interventions

Background:

• Dyslipidemia is a primary risk factor for cardiovascular diseases (CVDs), contributing significantly to global health burdens.
• Rice bran contains bioactive compounds like γ-oryzanol and tocotrienols with demonstrated lipid-modulating properties.

Purpose of the Study:

• To conduct a meta-analysis evaluating the impact of rice bran on lipid profiles (TG, TC, LDL-C, HDL-C).
• To identify factors influencing rice bran's efficacy in diverse populations and intervention settings.

Main Methods:

• Systematic literature search of PubMed, Web of Science, and Scopus for randomized controlled trials (RCTs) up to November 2024.
• Meta-analysis of 11 RCTs (572 participants) with subgroup analyses based on intervention form, dosage, duration, region, and participant characteristics.

Main Results:

• Rice bran significantly reduced triglycerides (-15.13 mg/dL), total cholesterol (-11.80 mg/dL), and LDL-C (-15.11 mg/dL).
• Rice bran oil showed greater efficacy for TC and LDL-C reduction compared to whole rice bran.
• Higher doses (≥30 g/mL) and longer durations (>4 weeks) enhanced lipid-lowering effects, with greater benefits observed in Asian populations.

Conclusions:

• Rice bran, especially as rice bran oil, is a functional food that significantly improves lipid profiles, aiding in CVD prevention.
• Further long-term studies in diverse populations are recommended to confirm efficacy and elucidate mechanisms.