Rice bran oil: a cholesterol drop the trials do not agree on

Across 11 randomized trials in 572 people, rice bran and rice bran oil together lowered LDL cholesterol by 15.11 mg/dL (95% CI 5.66 to 24.56) and total cholesterol by 11.80 mg/dL, with moderate heterogeneity and no change in HDL. In the five of those trials that used the oil, small and mostly run in Asia, LDL fell by 14.55 mg/dL (95% CI 5.87 to 23.24). The answer is still unsettled. An earlier meta-analysis of 8 trials of rice bran supplements found no significant change in LDL, a difference of -1.68 mg/dL (95% CI -8.46 to 5.09), and an umbrella review rated the LDL evidence for rice bran oil moderate to very low certainty. The two meta-analyses pooled different products and different trials. In the larger one the fall in total cholesterol was clear in Asian trials, 16.24 mg/dL, and small and not significant in US trials, 3.61 mg/dL (95% CI -14.11 to 6.90), with region tangled up with dose, product form and starting cholesterol. Against other unsaturated oils it shows no edge: in a 15 person feeding trial LDL was 109 mg/dL on rice bran oil and 109 on canola.

The numbers, per 3.5 oz (100 g)

How much is actually in it

• The rice bran oil used in one trial carried 1.65 g gamma-oryzanol per 3.5 oz (100 g), a compound most other cooking oils lack. — one commercial rice bran oil, analyzed composition Evidence D source
  Gamma-oryzanol 1.65 g/100 g; tocotrienols and tocopherols about 0.281 mg/g
• USDA lists 3.5 oz (100 g) of rice bran oil at 32.3 mg vitamin E, 215% of the Daily Value, with 19.7 g saturated fat. — USDA FoodData Central SR Legacy, one reference record (n = 1 record) Evidence E source
  Vitamin E 32.3 mg per 3.5 oz (100 g) (215% DV); fat 100 g (128% DV); saturated fat 19.7 g (98% DV)

What a real portion looks like

• Trials that moved blood lipids used about 1.1 oz (30 g) of rice bran oil a day, roughly 2 tablespoons. — overweight or obese adults with metabolic syndrome in an 8-week trial (n = 50) Evidence B source
  Dose 30 g/day, about 2 tablespoons
• In a 2021 survey of 1248 Australian adults, 4.6% named rice bran oil as a household oil, far behind olive oil at 84.5%. — 1248 adults living in Australia, online survey July-December 2021 (n = 1248) Evidence C source
  Rice bran oil 4.6%; olive oil 84.5% main oil

What cooking and storage change

• Lab heating at 180 C for up to 1368 hours destroyed 91-97% of the gamma-oryzanol in rice bran oil, with physically refined oil keeping more than chemically refined. — chemically and physically refined rice bran oils heated at 100, 140 and 180 C Evidence D source
  Oryzanol loss at 180 C: 97.05% chemically refined vs 91.11% physically refined; at 100 C 53.47% vs 38.11%

What it does to your health

• Across 11 RCTs with 572 participants, rice bran products lowered LDL cholesterol by about 15 mg/dL and total cholesterol by about 12 mg/dL, with no change in HDL. — 572 participants in 11 randomized controlled trials of rice bran or rice bran oil (n = 572) Evidence A source
  TG -15.13 mg/dL (95% CI -29.56 to -0.71); TC -11.80 mg/dL (95% CI -19.35 to -4.25); LDL-C -15.11 mg/dL (95% CI -24.56 to -5.66); HDL-C no significant change
• In the rice bran oil trials of this meta-analysis, the oil lowered total cholesterol by about 19 mg/dL and LDL cholesterol by about 15 mg/dL. — subgroup of 5 rice bran oil RCTs within an 11-trial meta-analysis (n = 5 RCTs) Evidence A source
  TC -19.24 mg/dL (95% CI -28.16 to -10.33); LDL-C -14.55 mg/dL (95% CI -23.24 to -5.87); I2 0%
• An umbrella review of 48 studies with 206 meta-analyses rated the LDL lowering from rice bran oil, canola oil and virgin olive oil as moderate to very low certainty. — adults in 48 systematic reviews covering 206 meta-analyses of vegetable oils (n = 48 studies) Evidence A source
  Beneficial direction for total and LDL cholesterol; certainty moderate to very low (GRADE)
• In 60 healthy adults, 2.1 g a day of plant sterols concentrated from rice bran oil lowered LDL by 7.7 mg/dL (0.20 mmol/L), about 9%, over 3 weeks. — 28 men and 32 women, normolipemic, 29 g/day margarine for 3 weeks each (n = 60) Evidence B source
  LDL-C -7.7 mg/dL (95% CI -12 to -3.9; metric: -0.20 mmol/L, -0.30 to -0.10); total cholesterol -7.3 mg/dL (95% CI -12 to -2.7; metric: -0.19 mmol/L, -0.31 to -0.07)

Safety, limits and interactions

• In an 8-week open-label RCT in 400 people, a cooking oil blend of 80% rice bran and 20% sesame oil lowered fasting and after-meal blood glucose, used alone or together with glibenclamide. — 300 adults with type 2 diabetes and 100 normoglycemic adults, blend as cooking oil for 8 weeks (n = 400) Evidence B source
  Fasting and postprandial glucose significantly reduced (P < .001); HbA1c and LDL fell with blend alone or with glibenclamide 5 mg/d
• In people with high blood pressure, a rice bran and sesame oil blend used as the only cooking oil together with nifedipine gave the greatest blood pressure reduction of the groups over 60 days. — 300 hypertensive and 100 normotensive adults, blend as the only cooking oil for 60 days, nifedipine 20 mg/d arms (n = 400) Evidence C source
  Greatest blood pressure reduction with blend plus nifedipine; no sizes in abstract
• In an 8-week RCT in 50 adults with metabolic syndrome, none of those taking 1.1 oz (30 g) of rice bran oil a day reported adverse effects. — overweight or obese adults with metabolic syndrome, 23 analyzed in the rice bran oil arm, 30 g/day for 8 weeks (n = 50) Evidence B source
  No adverse effects or complications reported in the rice bran oil group
• Rice bran oil contaminated with PCBs and dioxins poisoned people in Japan in 1968, and 40 years later survivors still had more skin and other symptoms. — 1131 Yusho patients surveyed in 2008 vs an age- and area-matched general population, Japan (n = 1131) Evidence C source
  Skin pigmentation and acneiform eruption more prevalent; also fatigue, arthralgia, numbness after adjustment

What people believe that the data does not support

• In a 10-week crossover trial in 14 adults, rice bran oil lowered LDL by 7% while defatted rice bran fiber did not, so the effect sits in the oil and not the fiber. — 14 moderately hypercholesterolemic adults, rice bran oil as one third of dietary fat, 10-week crossover (n = 14) Evidence B source
  LDL cholesterol -7% (P < 0.0004), HDL unchanged; defatted rice bran no lipid change
• In a 15-person double-blind feeding trial, rice bran oil lowered cholesterol no more than canola or corn oil, with LDL of 109 mg/dL on both rice bran and canola. — 15 middle-aged and elderly adults with raised LDL, 32-day periods per oil, all food supplied (n = 15) Evidence B source
  LDL-C 109 (rice bran), 109 (canola), 108 (corn), 112 (olive) mg/dL
• In 30 men, rice bran oil with 16 times more gamma-oryzanol lowered cholesterol no better than a low-oryzanol oil, both cutting LDL by 10.5% over 4 weeks. — 30 mildly hypercholesterolemic men aged 38-64, 50 g/day rice bran oil for 4 weeks (n = 30) Evidence B source
  Both oils: total cholesterol -6.3%, LDL-C -10.5%, LDL/HDL ratio -18.9%; no difference between 0.05 and 0.8 g/day oryzanol

Who this works differently for

• The cholesterol drop from rice bran was clear in Asian trials, about 16 mg/dL for total cholesterol, but small and not significant in US trials. — regional subgroups of an 11-trial meta-analysis of rice bran and rice bran oil (n = 11 RCTs) Evidence A source
  Asia TC -16.24 mg/dL (95% CI -24.56 to -7.91); USA TC -3.61 mg/dL (95% CI -14.11 to 6.90)
• In an 8-week RCT in 75 postmenopausal women with type 2 diabetes, 30 g a day of rice bran oil in place of sunflower oil cut LDL by 8.9 mg/dL and triglycerides by 38.6 mg/dL. — 75 postmenopausal women with type 2 diabetes, Shiraz, Iran, 30 g/day oil for 8 weeks (n = 75) Evidence B source
  RBO: TG -38.62, TC -17.25, LDL-C -8.90 mg/dL vs sunflower control +7.01, +4.06, +2.90 mg/dL; HDL unchanged
• In 40 men with coronary artery disease, 30 g a day of rice bran oil for 8 weeks gave a lower Castelli risk index than sunflower oil, 3.29 against 4.61. — 40 men with coronary artery disease, mean age 56, 30 g/day oil plus standard diet for 8 weeks (n = 40) Evidence B source
  Castelli risk index I 3.29 vs 4.61; II 1.52 vs 2.20; TyG index 8.73 vs 9.13 (adjusted means)

What is still unknown

• An earlier meta-analysis of 8 RCTs found no significant effect of rice bran supplements on LDL cholesterol, about -1.7 mg/dL, so the benefit is not settled across all forms. — 8 RCTs (11 effect sizes) of rice bran supplementation, searched to June 2022 (n = 8 RCTs) Evidence A source
  LDL-C WMD -1.68 mg/dL (95% CI -8.46 to 5.09); TC -0.68 mg/dL (95% CI -7.25 to 5.88); TG -11.38 mg/dL (95% CI -27.73 to 4.96)

The bottom line

The trials that moved blood lipids gave about 1.1 oz (30 g) of oil a day, roughly 2 tablespoons, a dose taken from one trial and repeated in two others. In 75 postmenopausal women with type 2 diabetes at one Iranian center, 30 g a day in place of sunflower oil for 8 weeks lowered LDL by 8.90 mg/dL and triglycerides by 38.62 mg/dL. In men with coronary artery disease, a post hoc analysis of 37 completers found a lower Castelli risk index on rice bran oil than on sunflower oil, 3.29 against 4.61, which is a surrogate ratio built from blood lipids. USDA lists 3.5 oz (100 g) of the oil at 32.3 mg vitamin E, 215% of the Daily Value, and 19.7 g saturated fat, from a single record with no measured spread. The oil is also sold on gamma-oryzanol, which one brand used in a trial carried at 1.65 g per 3.5 oz (100 g). The oryzanol content did not change the result. In 30 men eating 1.8 oz (50 g) a day for 4 weeks, oil with 16 times more oryzanol lowered LDL by the same 10.5% as a low oryzanol oil, in a short trial without a wash-out. In a 10 week crossover in 14 adults, rice bran oil lowered LDL by 7% and defatted rice bran did not change blood lipids. Plant sterols concentrated from the oil into margarine, 2.1 g a day, cut LDL by 7.7 mg/dL (0.20 mmol/L) over 3 weeks in 60 healthy adults, at a sterol dose far above what cooking with the oil supplies. In the lab, heating at 180 C for up to 1368 hours destroyed 91 to 97% of the oryzanol, over a heating time far longer than any home frying. Two open-label trials tested an 80:20 blend of rice bran and sesame oil as the cooking oil. In 300 adults with type 2 diabetes it lowered fasting and after-meal glucose over 8 weeks, alone and together with glibenclamide. In people with high blood pressure the blend together with nifedipine gave the largest drop of the groups over 60 days, though that abstract gives no sizes and does not say the groups were randomized. If you take drugs for blood sugar or blood pressure, a change of cooking oil is worth mentioning to whoever prescribes them. In 23 adults with metabolic syndrome who took 30 g a day for 8 weeks, nobody reported side effects, and a trial that small cannot prove safety. The 1968 Yusho poisoning in Japan came from rice bran oil contaminated with PCBs and dioxins during production. Forty years later survivors still had more skin symptoms than a matched general population. We found no studies in pregnancy, children or kidney disease.

Sources

1. rbol-r2-16 · composition, single product
   In terms of its bioactive contents, γ-oryzanol is found at a concentration of 1.65 g/100 g of RBO.
   Lipids in Health and Disease, 2024 · checked 2026-09-29
2. rbol-r2-17 · USDA FoodData Central SR Legacy, dataset
   Oil, rice bran (FDC 171013, SR Legacy, Fats and Oils): vitamin E 32.3 mg per 100 g = 215% DV; fat 100 g = 128% DV; saturated fat 19.7 g = 98% DV; Foundation samples 0, CoFID match none
   USDA FoodData Central, SR Legacy, FDC 171013 · checked 2026-09-29
3. rbol-r2-15 · RCT, open label
   The patients in the control group were given a standard diet alone, whereas the intervention group subjects were additionally asked to consume RBO (30 g, equivalent ∼ 2 tablespoon per day).
   Lipids in Health and Disease, 2024 · checked 2026-09-29
4. rbol-r2-20 · cross-sectional survey
   Fewer households reported using rice bran oil (4·6 %), canola oil (4·3 %) and vegetable oil (1·8 %).
   Br J Nutr, 2023 · checked 2026-09-29
5. rbol-r2-18 · laboratory study
   The chemically refined rice bran oil presented a lower γ-oryzanol content than the physically refined rice bran oil at all heating temperatures.
   Journal of the Science of Food and Agriculture, 2021 · checked 2026-09-29
6. rbol-r2-01 · meta-analysis of RCTs
   Eleven RCTs involving 572 participants met the inclusion criteria. Pooled results showed that rice bran consumption significantly reduced TG (-15.13 mg/dL; 95% CI: -29.56, -0.71), TC (-11.80 mg/dL; 95% CI: -19.35, -4.25), and LDL-C (-15.11 mg/dL; 95% CI: -24.56, -5.66) with moderate heterogeneity (I2 = 38.1-63.0%). No significant changes were observed for HDL-C.
   Nutrients, 2024 · checked 2026-09-29
7. rbol-r2-02 · meta-analysis of RCTs, subgroup
   Rice bran oil (RBO) significantly reduced both TC (effect size: −19.24; 95% CI: −28.16, −10.33) and LDL-C (effect size: −14.55; 95% CI: −23.24, −5.87), with no heterogeneity (I2 = 0.00%).
   Nutrients, 2024 · checked 2026-09-29
8. rbol-r2-05 · umbrella review
   Moderate to very low certainty evidence showed that monounsaturated and polyunsaturated fatty acids such as canola oil, virgin olive oil, and rice bran oil are beneficial in reducing serum total cholesterol and low-density lipoprotein (LDL) concentrations.
   Adv Nutr, 2024 · checked 2026-09-29
9. rbol-r2-11 · RCT, crossover
   Intake of 2.1 g plant sterols/d from rice bran oil decreased total cholesterol by 0.19 mmol/L (95% CI: -0.31, -0.07 mmol/L) and LDL cholesterol by 0.20 mmol/L (95% CI: -0.30, -0.10 mmol/L).
   Am J Clin Nutr, 2000 · checked 2026-09-29
10. rbol-r2-12 · RCT, open label
    At week 4 and week 8, type 2 diabetes mellitus patients treated with sesame oil blend or glibenclamide or combination of glibenclamide and sesame oil blend showed significant reduction of fasting and postprandial blood glucose (P <.001).
    Am J Med, 2016 · checked 2026-09-29
11. rbol-r2-13 · open-label intervention
    Sesame oil blend with nifedipine-treated group showed greatest reduction in blood pressure.
    J Clin Lipidol, 2016 · checked 2026-09-29
12. rbol-r2-14 · RCT, open label
    None of the patients in the RBO group experienced any adverse effects or complications following the consumption of RBO, and the oil was well tolerated.
    Lipids in Health and Disease, 2024 · checked 2026-09-29
13. rbol-r2-19 · prevalence survey
    Yusho, which refers to a mass poisoning caused by the ingestion of rice bran oil contaminated with polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans, was first reported in October 1968 in Japan.
    Arch Environ Contam Toxicol, 2018 · checked 2026-09-29
14. rbol-r2-08 · RCT, crossover
    Defatted rice bran did not lower lipid concentrations. In study 2, total cholesterol was significantly lower with consumption of the diet containing rice bran oil than with consumption of the control diet. Moreover, with consumption of the rice bran oil diet, LDL cholesterol decreased by 7% (P < 0.0004), whereas HDL cholesterol was unchanged.
    Am J Clin Nutr, 2005 · checked 2026-09-29
15. rbol-r2-09 · RCT, crossover
    Plasma cholesterol and LDL-C concentrations were similar and statistically indistinguishable when the subjects consumed the rice bran, canola, and corn oil-enriched diets and lower than when they consumed the olive oil-enriched diet.
    Arterioscler Thromb, 1994 · checked 2026-09-29
16. rbol-r2-10 · RCT
    The two RBO types were not significantly different with respect to effects on various cholesterol parameters, at 2 and 4 wks, including total cholesterol, LDL-, HDL- and LDL/HDL cholesterol ratio. Low and high gamma-oryzanolcontaining RBO feeding for 4 wks lowered total plasma cholesterol (6.3 %), LDL-C (10.5 %) and the LDL-C/HDL-C ratio (18.9 %).
    Eur J Nutr, 2005 · checked 2026-09-29
17. rbol-r2-03 · meta-analysis of RCTs, subgroup
    Regionally, studies conducted in Asia showed significant reductions in TC (effect size: −16.24; 95% CI: −24.56, −7.91; I2 = 16.0%), with low heterogeneity, and LDL-C (effect size: −15.54; 95% CI: −23.88, −7.20; I2 = 0.00%), with no heterogeneity. Studies from the USA showed smaller and non-significant reductions in TC (effect size: −3.61; 95% CI: −14.11, 6.90; I2 = 37.5%)
    Nutrients, 2024 · checked 2026-09-29
18. rbol-r2-06 · RCT
    At 8 weeks, mean of serum levels of TG (mg/dL), TC (mg/dL), and LDL-C (mg/dL) significantly decreased in the CO group (-23.66, P < .001; -11.92, P < .001; and -6.33, P = .013, respectively) and RBO group (-38.62, P < .001; -17.25, P < .001; and -8.90, P = .002, respectively) compared with the controls (7.01, 4.06, and 2.90, respectively).
    J Clin Lipidol, 2016 · checked 2026-09-29
19. rbol-r2-07 · RCT, post hoc
    Analysis of covariance test in which potential confounders and baseline levels were considered, indicated that using RBO compared to SFO reduced Castelli's risk index I and II (adjusted means:3.29, 1.52 vs. 4.61, 2.20, respectively)
    Lipids Health Dis, 2021 · checked 2026-09-29
20. rbol-r2-04 · meta-analysis of RCTs
    Meta-analysis of eight RCTs (with 11 effect sizes) showed no significant effect of rice bran supplementation on serum levels of triglyceride (WMD: -11.38 mg/dl; 95% CI: -27.73, 4.96; P = 0.17), total cholesterol (WMD: -0.68 mg/dl; 95% CI: -7.25, 5.88; P = 0.834), low-density lipoprotein cholesterol (WMD: -1.68 mg/dl; 95% CI: -8.46, 5.09; P = 0.627)
    Syst Rev, 2023 · checked 2026-09-29