rice bran and Increased HDL Cholesterol Levels

Research synthesisLow evidenceMixed effect size3 studies · 2 beneficial · 1 neutral · 0 harmful

Across 3 studies, 2 reported beneficial effects (one small, one large) on HDL cholesterol, while 1 meta-analysis found no significant effect. The median study duration was 42 days. The most studied dose was 30 g/d of rice bran oil, but doses varied; populations included healthy adults with low dietary fiber intake and overweight/obese adults with metabolic syndrome.

Studied populations: adults with low dietary fiber intake, overweight/obese adults with metabolic syndrome

Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. The two beneficial studies used different forms (defatted rice bran bread and rice bran oil), while the meta-analysis included various rice bran preparations and found no significant effect, conflicting with the individual RCTs. Further research is needed to reconcile these discrepancies.

Generated Jul 12, 2026

Doses used in studies

g/day: 30 (median 30, IQR 30–30) — 1 study
slices/day: 3–4 (median 3.5, IQR 3–4) — 1 study

Time to effect

Median: 6 weeks · IQR 5 weeks–7 weeks · Range 4 weeks–8 weeks — Reported in 2 of 3 studies

Safety in these studies

Overall tolerabilityReported
No significant differences were observed in the primary outcome, microbial taxa composite within and between groups (False Discovery Rate (FDR) correction, p > 0.10). ... for most of the other outcomes between groups (p > 0.05).
from: Effects of defatted rice bran-fortified bread on gut microbiome, cardiovascular risk, gut

3 of 3 papersPopulation:

Effects of defatted rice bran-fortified bread on gut microbiome, cardiovascular risk, gut discomfort, wellbeing and gut physiology in healthy adults with low dietary fibre intake.
- 2025-06
- RCT · n = 15
- Clinical nutrition ESPEN 67
- - Hwei Min Ng
  - Jasjot Maggo
  - Catherine L Wall
  - Simone B Bayer
  - Jane A Mullaney
  - Diana Cabrera
  - Karl Fraser
  - Janine M Cooney
  - Catrin S Günther
  - Warren C McNabb
  - Meika Foster
  - Chris Frampton
  - Richard B Gearry
  - Nicole C Roy
- PubMed: 40127766
- DOI: 10.1016/j.clnesp.2025.03.045
15 Insights on
- Increased HDL Cholesterol Levels
- High evidence
- Adults
Only mean serum high-density lipoprotein (HDL) concentrations significantly increased (p = 0.006) in the DRB group compared to the control group.
Effect
Beneficial
Effect size
Small
Significant
Yes
Dose
Three (females) or four (males) slices of DRB-fortified bread daily
An open label randomized controlled trial of the effects of rice bran oil on cardiometabolic risk factors, lipid peroxidation and antioxidant status in overweight/obese adults with metabolic syndrome.
- 2024-08-28
- RCT · n = 50
- Lipids in health and disease 23(1)
- - Marjan Mahdavi-Roshan
  - Nargeskhatoon Shoaibinobarian
  - Mehdi Evazalipour
  - Arsalan Salari
  - Zeinab Ghorbani
  - Amir Savarrakhsh
  - Zahra Ahmadnia
- PubMed: 39198792
- DOI: 10.1186/s12944-024-02260-4
16 Insights on
- Increased HDL Cholesterol Levels
- High evidence
- Clinical
RBO consumption resulted in significantly higher levels of HDL-C (P value = 0.004; ES:0.94)
Effect
Beneficial
Effect size
Large
Significant
Yes
Dose
30 g/d
The effects of rice bran supplementation for management of blood lipids: A GRADE-assessed systematic review, dose-response meta-analysis, and meta-regression of randomized controlled trials.
- 2023-04-12
- Meta-Analysis
- Systematic reviews 12(1)
- - Zahra Hariri
  - Fatemeh Afzalzade
  - Golbon Sohrab
  - Saeede Saadati
  - Zahra Yari
- PubMed: 37046340
- DOI: 10.1186/s13643-023-02228-y
4 Insights on
- Increased HDL Cholesterol Levels
- High evidence
Meta-analysis of eight RCTs (with 11 effect sizes) showed no significant effect of rice bran supplementation on serum levels of high-density lipoprotein cholesterol (WMD: 0.16 mg/dl; 95% CI: -1.52, 1.85; P = 0.848)
Effect
Neutral
Effect size
Small
Significant
No

rice bran and Increased HDL Cholesterol Levels

Effects of defatted rice bran-fortified bread on gut microbiome, cardiovascular risk, gut discomfort, wellbeing and gut physiology in healthy adults with low dietary fibre intake.

An open label randomized controlled trial of the effects of rice bran oil on cardiometabolic risk factors, lipid peroxidation and antioxidant status in overweight/obese adults with metabolic syndrome.

The effects of rice bran supplementation for management of blood lipids: A GRADE-assessed systematic review, dose-response meta-analysis, and meta-regression of randomized controlled trials.