Rice Bran
Scientific Name(s): Oryza sativa L.
Common Name(s): Rice bran oil, Rice bran protein, Rice bran wax
Medically reviewed by Drugs.com. Last updated on Apr 21, 2022.
Clinical Overview
Use
Rice bran oil is used extensively in Asia for cooking because of its high smoke point. Potential benefit with use of rice bran oil and its components (particularly gamma oryzanol) for dermatological applications and dyslipidemia has been suggested; however, due to the possible severity of dyslipidemia, rice bran variations should not be used in lieu of standard medical care. Clinical trial data are limited by poor methodology and quality, making it difficult to support suggested clinical applications.
Dosing
Hypercholesterolemia: A dosage of 50 mg/day of a tocotrienol-rich fraction of rice bran (either alone or in combination with lovastatin) was administered for 35 days as part of a 5-phase study over 25 weeks. In another study of hypercholesterolemic men, gamma oryzanol was administered at a low dose (50 mg/day) or high dose (800 mg/day) for 4 weeks. Exercise performance: Gamma oryzanol 500 to 600 mg/day for 9 weeks has been evaluated for its effects on exercise training and muscle strength.
Contraindications
Contraindications have not been identified; however, use of the component phytic acid in renal impairment is not advised.
Pregnancy/Lactation
Information regarding safety and efficacy in pregnancy and lactation is lacking.
Interactions
None well documented.
Adverse Reactions
Rice bran oil and extracts are considered very safe, with only a low incidence of minor allergic reactions reported.
Toxicology
No data.
Scientific Family
- Poaceae (grass)
Source
The rice plant grows up to 1.8 m in height, depending on location and conditions. It has long, slender leaves and small wind-pollinated flowers. The species is native to South Asia and some parts of Africa but is widely cultivated. As a cereal grain, it is a major source of nutrition for a large portion of the world's population.Murray 1996, USDA 2017
The outer chaff of the rice seeds are milled off to produce brown rice, which is covered by bran layers; rice bran oil is extracted from the bran fraction of rice kernels or seeds of the rice plant. Gamma oryzanol, as well as other constituents, are extracted from rice bran oil.Park 2017
History
Rice bran oil is used extensively in cooking, especially in Asia. It has a nut-like flavor and a high smoke point, making it suitable for deep frying and cooking at high temperatures. Rice bran extracts are used in the cosmetic industry.
Isolation, extraction, and purification of gamma oryzanol were first reported in the mid 1950s. It has been used in Japan as a medicine since 1962, first to treat anxiety and later in menopause. Gamma oryzanol and rice bran oil therapy have been used to manage elevated cholesterol and triglyceride levels since the late 1980s.Murray 1996, Safety Assessment 2006
Chemistry
Rice bran oil, gamma oryzanol, ferulic acid, and phytic acid are chemical constituents of rice seed.
The bran fraction is approximately 8% of the rice kernel and consists of saturated and unsaturated fatty acids and alcohols, phytosterols, tocotrienols, tocopherols, vitamins (including biotin, vitamin B12, thiamine, and niacin), and minerals (including phosphorous, magnesium, potassium, and zinc).
Gamma oryzanol is a mixture of esters of sterols (eg, campestrol, stigmasterol, beta-sitosterol) and triterpene alcohols and their ferulate est...
