Gamma Oryzanol
syn. ferulic acid esters
syn. rice bran oil (extract)
Description:
Gamma oryzanol is a mixture of ferulic acid esters, sterols, and triterpene alcohols extracted from Japanese rice bran oil (oryza sativa). Ferulic acid is regarded as the primary active ingredient. Gamma oryzanol has been used as a natural remedy for decades, and appears to have a number of potential health promoting properties.357 For one, it is a strong antioxidant. It also appears to be an effective natural treatment for high cholesterol. One study showed a 300 mg daily dosed significantly lowered total (204 to 176 mg/dL) and LDL (bad) cholesterol (124 to 101 mg/dL) levels in a group of men during 12 weeks of supplementation.358 Gamma oryzanol may also protect against ulcers,359 and alleviate certain symptoms of menopause.360
Gamma oryzanol supplements have been marketed to bodybuilders and athletes off and on for many years. The typical claim is that the products will increase anabolic (testosterone, growth hormone) levels, thereby supporting greater improvements in muscle size and strength. Unfortunately, there is little actual clinical or empirical data to support the use of gamma oryzanol in this manner. The one relevant independent clinical study with exercising adults reported no improvements in testosterone, growth hormone, or any marker of exercise performance with gamma oryzanol supplementation. Furthermore, some studies with animals suggest that ferulic acid may actually interfere with muscle gains and anabolic hormone levels.361,362 Whether or not gamma oryzanol has any value as a sport supplement remains to be seen.
Promoted Benefits:
Gamma oryzanol is promoted to increase testosterone and growth hormone levels, and support muscle mass and strength gains.
Clinical Studies:
The use of gamma oryzanol as a sport supplement is supported by animal data only. Its Clinical Support Rating is 2 (2/5).
The most commonly cited independent study demonstrating a positive effect on anabolic hormone levels involved the intravenous injection of ferulic acid (the principle active component of gamma oryzanol) in a group of cows.363 The animals noticed a slight increase in growth hormone levels shortly after injection. This increase was short-lived, however, with levels returning to baseline approximately 60-90 minutes after administration.
There has been one independent placebo-controlled clinical study on the effects of gamma oryzanol supplementation by exercising adults.364 It involved the use of 500 mg daily for a period of nine weeks. All subjects followed a controlled resistance training program. The study reported no additional improvements in any measure of performance (bench press strength, squat strength, or vertical jump power) as a result of gamma oryzanol supplementation. Also, there were no differences in anabolic/catabolic hormone levels (testosterone, cortisol, growth hormone, or insulin) compared to those subjects taking placebo. This study does not support of the use gamma oryzanol as a sport supplement.
Further research is needed to determine if there is any ergogenic value to the use of gamma oryzanol by athletic individuals.
Empirical Evidence:
Gamma oryzanol has been widely used as a standalone supplement. The feedback on this supplement tends to be poor. A strong majority of people appear unable to attribute any specific benefit to gamma oryzanol with regard to muscle mass or strength increases. Most report the supplement to be ineffective. Only a small number of users seem to have positive experiences. Given the relatively low frequency of such reports, however, it is difficult to know if they are genuine, or the subject of placebo effect. Gamma oryzanol has an Empirical Evidence Rating of 1 (1/5).
Effective Dosage:
An effective dosage of this supplement has not been established. Manufacturers commonly recommend 300-500 mg per day.
Side Effects / Safety:
Gamma oryzanol appears to be a well-tolerated natural supplement, with no health-significant side effects.
