Mi Pi Kang

Star

Oryza sativa L.

Not yet clinically reviewed

Genus: Oryza Species: sativa Pinyin: Mi Pi Kang
Rice bran米皮糠

Traditionally used for

  • Digestion
  • Bowel health
Strong evidence · 5 studies

☯ TCM Properties

Category: regulating qi
Temperature: warm
Taste: sweet, pungent
Meridians: stomach, large intestine
Functions:

Strengthens the Spleen and Opens the Appetite; Descends Qi; Promotes Bowel Movement; Promotes Digestion and Resolves Food Stagnation

Traditional Chinese Uses

Mi Pi Kang (rice bran) is a neutral, mild food-herb used in Chinese medicine primarily for its Spleen-strengthening and digestive-supporting properties. It addresses poor appetite, loose stools, and Spleen-Qi deficiency, and has been applied historically for certain nutrient-deficiency conditions. As a gentle food substance, it is commonly incorporated into dietary therapy for digestive complaints.

Click a node for details · double-click to expand it · Ctrl/⌘ + scroll or two fingers to zoom and pan.

Loading graph…

Botanical Description

Oryza sativa L. (Poaceae), Asian rice, is an annual cultivated grass 1-1.8 m tall with hollow culms, linear leaves, and terminal panicles bearing one-seeded grains enclosed by hard husks. Mi Pi Kang is the bran layer, the brown pericarp-and-aleurone fraction removed during milling of brown rice to produce white rice. The bran is rich in B-vitamins (especially thiamine), gamma-oryzanol, phytic acid, dietary fiber, and lipids. In traditional Chinese medicine, Mi Pi Kang is sweet, bland, and neutral, entering the spleen and stomach channels; it tonifies the spleen, harmonizes the middle burner, and supplements qi, used historically for beriberi (thiamine-deficiency edema) and chronic digestive weakness in patients depending on polished rice as a staple. It exemplifies the classical TCM use of food byproducts as medicines for nutritional disorders.

Active Constituents

Thiamine (vitamin B1)

Water-soluble B vitamin

Concentration: concentrated in the seed coat and aleurone layer that milling removes; largely absent from polished white rice

Thiamine is the constituent that made rice bran the classical remedy for what Chinese medicine calls foot qi. Beriberi is a thiamine deficiency disease of populations eating polished rice, and the bran fraction stripped off during milling is where the vitamin sits, so a bran decoction or porridge restores exactly what polishing removed. This is a nutritional replacement effect, not a pharmacological one.

Insoluble dietary fibre with retrograded (resistant) starch

Non-starch polysaccharide and resistant starch

Concentration: supplied about 17.1 g of indigestible residue per day in the controlled human feeding study of rice bran

This is the fraction behind the classical claim that rice bran opens the bowel. In a controlled crossover in eight men, rice bran raised faecal mass and stool frequency more than a matched amount of wheat bran residue, and both accelerated whole-gut transit; the authors attributed the unusually efficient stool bulking to a high content of retrograded starch.

Gamma-oryzanol

Mixture of steryl and triterpene alcohol ferulates

Concentration: a principal bioactive of rice bran and rice bran oil; content varies substantially with cultivar, degree of milling and storage, so no single figure applies to a decoction-grade bran

Gamma-oryzanol is the ferulate ester fraction credited with most of the antioxidant and lipid-modulating activity attributed to rice bran in modern trials. It is far more concentrated in rice bran oil than in whole bran, which is why oil-based interventions outperform whole-bran interventions on cholesterol endpoints.

Tocotrienols

Vitamin E (tocotrienol) isomers

Tocotrienols contribute to the antioxidant capacity of the bran lipid fraction and are, with gamma-oryzanol, the constituents most often invoked to explain the lipid-lowering signal seen in rice bran trials.

Ferulic acid

Hydroxycinnamic acid

Ferulic acid occurs both free and bound into the bran cell wall and as the acyl component of gamma-oryzanol. It is a standard marker of the phenolic antioxidant content of the bran.

Phytic acid

Inositol hexakisphosphate

Phytate is abundant in cereal bran and chelates divalent cations. It is the reason a bran-heavy regimen reduces the absorption of dietary and supplemental iron, zinc and calcium, and it is the practical basis for separating a bran decoction from mineral supplements.

Inorganic arsenic

Metalloid contaminant, not a plant metabolite

Concentration: in a global survey of 53 rice brans, mean inorganic arsenic ranged from 0.017 mg/kg (Guatemalan samples) to 0.619 mg/kg (Thai samples)

Rice concentrates arsenic in the bran layer, so the medicinal fraction is the fraction that carries the contaminant. In that survey, target hazard quotient and lifetime cancer risk thresholds were exceeded for adults, children and infants at the highest-arsenic bran intake scenario, and lifetime cancer risk was above threshold even at the median. This matters for prolonged daily dosing rather than for a short course, and it is a reason to prefer bran of known provenance.

⚠ Drug Interactions

Oral iron, zinc and calcium supplements

Moderate Evidence: Probable

Phytic acid in cereal bran chelates divalent cations in the gut lumen and forms poorly absorbed complexes. The effect is a property of the bran fraction itself rather than of any single rice cultivar, and it scales with the amount of bran taken.

Clinical note: Separate a Mi Pi Kang decoction from iron, zinc or calcium dosing by at least two hours, and recheck ferritin in patients being treated for iron deficiency while taking bran long term.

Narrow-therapeutic-index oral drugs (e.g. levothyroxine, digoxin, warfarin)

Moderate Evidence: Possible

Rice bran is a bulking fibre that increases stool mass and accelerates whole-gut transit in humans, and bran particle size measurably alters gastric emptying and small bowel transit on scintigraphy. Faster transit and a larger luminal fibre mass reduce the contact time available for absorption. Rice bran has not been studied against these specific drugs, so this is an extrapolation from its documented transit effect rather than a measured pharmacokinetic interaction.

Clinical note: Dose the bran at a different time of day from the drug and keep the daily bran amount steady rather than varying it, so any absorption effect stays constant.

Statins and other lipid-lowering agents

Minor Evidence: Probable

A meta-analysis of eleven randomised trials found rice bran lowered triglycerides, total cholesterol and LDL cholesterol, with rice bran oil producing larger effects on total and LDL cholesterol than whole rice bran. The direction of effect is the same as that of the drug, so the combination is additive rather than antagonistic.

Clinical note: Not a hazard, but recheck a lipid panel after adding sustained rice bran to a statin so that the drug dose is titrated against the real number.

Red yeast rice (Hong Qu, Monascus-fermented Oryza sativa)

Moderate Evidence: Established

Mi Pi Kang, Spermodermis Oryzae Sativae, is the milled seed coat of the rice grain. It is not red yeast rice, and it is not the sprouted grain Gu Ya (Fructus Oryzae Germinatus). Red yeast rice is the same botanical species fermented with Monascus purpureus and contains monacolin K, which is chemically identical to lovastatin and carries the full statin interaction, myopathy and rhabdomyolysis profile plus citrinin contamination risk. Plain rice bran contains no monacolin K and carries none of that. Because all three drugs are indexed under Oryza sativa, records and dispensary labels are readily conflated.

Clinical note: Confirm from the Latin pharmaceutical name which rice preparation is in hand. Spermodermis is the bran; a red-yeast product will be labelled as fermented rice or Monascus and must be handled as a statin.

Evidence Tier

Strong evidence · 5 studies

Recorded studies by study design, strongest design at the top. This is a study-design tier only, not a GRADE rating: it does not weigh risk of bias, consistency or precision.

Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description

Clinical Studies

Comparison of the effects on colonic function caused by feeding rice bran and wheat bran

Tomlin J, Read NW (1988) European Journal of Clinical Nutrition RCT

Eight healthy men took matched amounts of indigestible residue from rice bran (17.1 g/day) and wheat bran (15.0 g/day) for ten days each, with a ten-day unsupplemented control period, while collecting all stools. Rice bran increased faecal mass and stool frequency more than wheat bran did, and both accelerated whole-gut transit similarly. The authors suggested the efficient stool bulking of rice bran reflects its high retrograded starch content. This is the most direct human evidence for the classical indication of promoting bowel movement.

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

Park SY, Kim Y, Park MJ, Kim JY (2024) Nutrients systematic review Verified: Systematic review / meta-analysis

Eleven randomised controlled trials with 572 participants were pooled. Rice bran significantly reduced triglycerides (-15.13 mg/dL), total cholesterol (-11.80 mg/dL) and LDL cholesterol (-15.11 mg/dL), with no significant change in HDL cholesterol and moderate heterogeneity. Subgroup analysis showed rice bran oil outperformed whole rice bran on total and LDL cholesterol, and that doses of 30 g or more and durations beyond four weeks gave stronger effects. Practitioners should note that most of the effect comes from the oil, not from the crude bran used as Mi Pi Kang.

Supplementing the standard diet with brown rice bran powder might effectively improve the metabolic syndrome characteristics and antioxidant status: an open label randomized controlled trial

Ghorbani Z, Shoaibinobarian N, Zamani E, Salari A, Mahdavi-Roshan M, Porteghali P, Ahmadnia Z (2025) Food & Function RCT Verified: Randomized controlled trial

Fifty adults with metabolic syndrome were randomised to a standard diet alone or the same diet plus 15 g/day of brown rice bran powder for eight weeks. The bran group showed significant reductions in BMI, waist circumference, total and LDL cholesterol, fasting blood sugar and the triglyceride-glucose BMI index, and improvements in glutathione peroxidase and superoxide dismutase activity. Constipation rate also improved significantly, which is the endpoint closest to the traditional indication. The trial was open label, which limits confidence in the subjective gastrointestinal endpoint.

Rice bran supplementation modulates growth, microbiota and metabolome in weaning infants: a clinical trial in Nicaragua and Mali

Zambrana LE, McKeen S, Ibrahim H, Zarei I, Borresen EC, Doumbia L, Boré A, Cissoko A, et al. (2019) Scientific Reports RCT Verified: Randomized controlled trial

Healthy weaning infants aged 6 to 12 months in Nicaragua and Mali were randomised to no intervention or to escalating daily rice bran (1 to 5 g/day). Daily rice bran was safe and feasible and was associated with improved length-for-age z-scores in both cohorts, with weight-for-age improving only in the Mali infants. Gut microbiota and stool metabolome responses differed markedly between the two country cohorts. The relevance here is a documented safety and tolerability record for sustained rice bran dosing in a vulnerable group.

Therapeutic Effects of Biobran, Modified Arabinoxylan Rice Bran, in Improving Symptoms of Diarrhea Predominant or Mixed Type Irritable Bowel Syndrome: A Pilot, Randomized Controlled Study

Kamiya T, Shikano M, Tanaka M, Ozeki K, Ebi M, Katano T, Hamano S, Nishiwaki H, Tsukamoto H, Mizoshita T, et al. (2014) Evidence-Based Complementary and Alternative Medicine RCT

Forty patients with diarrhoea-predominant or mixed irritable bowel syndrome were randomised to Biobran or placebo for four weeks. Global assessment was rated effective in 63.2 percent of the Biobran group versus 30 percent of placebo, with significant falls in diarrhoea and constipation scores and in CRP in the active group only. Biobran is an enzymatically modified arabinoxylan derived from rice bran, not the crude bran used as Mi Pi Kang, so the result should not be transferred directly to a bran decoction.

Historical Texts

Ming Yi Bie Lu

Six Dynasties, compiled c. 500 CE by Tao Hongjing
Records the fine bran from the pestle head as treating sudden choking, the earliest recorded indication for this drug and the ancestor of its later use for dysphagia and oesophageal obstruction.

Ben Cao Gang Mu

Ming dynasty, 1596
The formal source entry for Mi Pi Kang. Li Shizhen gives it as sweet and acrid, warm, entering the Stomach and Large Intestine, opening the appetite, freeing the intestines, descending qi and grinding away accumulated masses, with the principal indications of oesophageal obstruction and foot qi. The foot qi indication is now understood as thiamine deficiency, which the seed coat directly corrects.

Shi Wu Ben Cao (Wang Ying)

Ming dynasty
States that rice bran frees the intestines, opens the appetite, descends qi and grinds away accumulated masses, the four-function formula later quoted by most materia medica.

Ben Jing Feng Yuan

Qing dynasty, 1695
Records rice bran for oesophageal obstruction and for dissolving long-standing accumulation in the stomach, noting it is especially suited to acute choking episodes.

References

  1. Weber AM, Baxter BA, McClung A, Lamb MM, Becker-Dreps S, Vilchez S, Koita O, Wieringa F, et al.. Arsenic speciation in rice bran: Agronomic practices, postharvest fermentation, and human health risk assessment across the lifespan . Environmental Pollution (2021) [DOI]
  2. Vincent R, Roberts A, Frier M, Perkins AC, MacDonald IA, Spiller RC. Effect of bran particle size on gastric emptying and small bowel transit in humans: a scintigraphic study. . Gut (1995) [DOI]

This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.

📝 Notes

Public notes from the community and your own private notes on Mi Pi Kang.

No notes yet.

Log in or register to add your own notes.

Back to Herb Database