Research synthesisModerate evidenceMixed effect size5 studies · 4 beneficial · 1 neutral · 0 harmful
Across 5 studies, 4 reported beneficial effects on reducing blood cholesterol, with effect sizes that are mixed (small to large). The highest-quality evidence (two meta-analyses) shows moderate reductions in total cholesterol (approximately 11–14 mg/dL). Effects are most studied at doses around 30 g/day of rice bran or rice bran oil, primarily in adults with metabolic syndrome or overweight/obesity. Median study duration was 56 days based on one trial, suggesting effects may appear within 8 weeks.
- Effective dose range: 30 g/day
- Studied populations: adults with metabolic syndrome or overweight/obese
Caveats: One meta-analysis (2023) found no significant effect on total cholesterol, contrasting with other positive results; this inconsistency may reflect differences in doses, formulations, or study populations. Most evidence comes from meta-analyses with moderate quality, and only one trial reported a large effect size. The predominant form (e.g., rice bran vs. rice bran oil) was not consistently reported across studies.
Generated May 25, 2026