Vitamins, Minerals and Dietary Supplements
What is oryzanol? Why do we need it?
Oryzanol (also referred to as gamma oryzanol) is a naturally occurring mixture of various plant chemicals, includic sterols and esters. It is found in a variety of plant foods such as rice bran, corn, and barley, but it is not easily absorbed by the body.
Some research suggests that oryzanol stimulates the release of natural pain-relieving substances called endorphins. Other studies suggest that oryzanol can increase testosterone levels and increase the growth of muscle tissue in athletes. Some bodybuilders and weight lifters use oryzanol to increase athletic performance and reduce fatigue; however, there is no definitive evidence that oryzanol helps to improve strength or increase endurance. There is also evidence that oryzanol may reduce cholesterol levels in the blood.
How much oryzanol should I take?
Because oryzanol is not an essential nutrient, recommended daily allowance levels have yet to be established. The bulk of research into oryzanol has used supplements ranging from 300 mg to 600 mg per day.
What forms of oryzanol are available?
Oryzanol occurs naturally in some plant foods, including rice bran, corn and barley, and some plant oils. Oryzanol is also available as a dietary supplement, usually as a capsule or liquid.
What can happen if I take too much oryzanol? Are there any interactions I should be aware of? What precautions should I take?
Research suggests that high amounts of oryzanol (>600 milligrams per day) for prolonged periods of time (.6 months) may cause a variety of adverse side-effects, including dry mouth, irritability, and light-headedness. If such side-effects occur, patients should consult with a health care provider about lowering dosage or stopping use of oryzanol.
As of this writing, there are no known drug interactions associated with oryzanol. As always, make sure to consult with a licensed health care provider before taking oryzanol or any other dietary supplement or herbal remedy.
References
- Berger A, Rein D, Schafer A, et al. Similar cholesterol-lowering properties of rice bran oil, with varied gamma-oryzanol, in mildly hypercholesterolemic men. Eur J Nutr March 2005;44(3):163-73.
- Cicero AF, Gaddi A. Rice bran oil and gamma-oryzanol in the treatment of hyperlipoproteinaemias and other conditions. Phytother Res June 2001;15(4):277-89.
- Fry AC, Bonner E, Lewis DL, et al. The effects of gamma-oryzanol supplementation during resistance exercise training. Int J Sport Nutr 1997;7:318-29.
- Jariwalla RJ. Rice-bran products: phytonutrients with potential applications in preventive and clinical medicine. Drugs Exp Clin Res 2001;27(1):17-26.
- Nystrom L, Makinen M, Lampi AM, et al. Antioxidant activity of steryl ferulate extracts from rye and wheat bran. J Agric Food Chem April 6, 2005;53(7):2503-10.
