rice bran and Reduced Low-Density Lipoprotein Level

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

Across 3 studies, 2 reported beneficial effects of rice bran on reducing low-density lipoprotein (LDL) levels, with effect sizes ranging from small to large. One neutral meta-analysis found no significant effect. The median study duration was 42 days (6 weeks), suggesting effects may appear after several weeks of supplementation. The limited evidence base (only 3 studies) and mixed results warrant caution.

Effective dose range: 30 grams per day of rice bran oil or defatted rice bran-fortified bread providing the equivalent of 30 grams daily
Studied populations: healthy adults with low dietary fiber intake and men with coronary artery disease

Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. The neutral meta-analysis (2023) included more RCTs and found no significant LDL reduction, contrasting with two individual RCTs showing benefit, which may indicate overestimation of effect in smaller trials. The beneficial studies used rice bran oil or defatted rice bran in bread, while the meta-analysis pooled various rice bran forms — form differences may contribute to inconsistent results.

Generated Jun 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
- Reduced Low-Density Lipoprotein Level
- High evidence
- Adults
mean total cholesterol (TC) to HDL concentration ratio significantly lowered (p = 0.02) 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
The effects of rice bran oil on left ventricular systolic function, cardiometabolic risk factors and inflammatory mediators in men with coronary artery disease: a randomized clinical trial.
- 2021
- RCT · n = 40
- Food & function 12(10)
- - Marjan Mahdavi-Roshan
  - Arsalan Salari
  - Zeinab Ghorbani
  - Zahra Nikpey
  - Motahare Haghighatkhah
  - Aboozar Fakhr Mousavi
  - Mahboobeh Gholipour
  - Amir Pourfarzad
- PubMed: 33881115
- DOI: 10.1039/d1fo00094b
11 Insights on
- Reduced Low-Density Lipoprotein Level
- High evidence
- Rigorous Journal
- Clinical
RBO significantly improved LVEF (51.34%) and reduced triglyceride (125.01 mg dl-1), blood sugar (110.4 mg dl-1), total cholesterol (123.01 mg dl-1) and low density lipoprotein (56.88 mg dl-1) levels compared to sunflower oil ((45.56%), (155.93 mg dl-1), (128.94 mg dl-1), (163.93 mg dl-1) and (83.79 mg dl-1), respectively) following a 8-week trial (P-values < 0.05).
Effect
Beneficial
Effect size
Large
Significant
Yes
Dose
30 grams per day
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
- Reduced Low-Density Lipoprotein Level
- High evidence
Meta-analysis of eight RCTs (with 11 effect sizes) showed no significant effect of rice bran supplementation on serum levels of low-density lipoprotein cholesterol (WMD: -1.68 mg/dl; 95% CI: -8.46, 5.09; P = 0.627)
Effect
Neutral
Effect size
Small
Significant
No

rice bran and Reduced Low-Density Lipoprotein Level

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.

The effects of rice bran oil on left ventricular systolic function, cardiometabolic risk factors and inflammatory mediators in men with coronary artery disease: a randomized clinical trial.

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.