Articles

Gamma Oryzanol

Introduction

Gamma oryzanol is a mixture of compounds, which occur in rice bran oil (1) and function as natural antioxidants in the plants where they occur. Studies conducted primarily in Japan report that gamma oryzanol supplementation is beneficial in the treatment of menopausal symptoms, elevated cholesterol, and numerous gastrointestinal conditions. (2)

Dosage Info

Dosage Range

30 to 300 mg daily.

Most Common Dosage

100 mg, 3 times daily.

Dosage Forms

Tablets, capsules, and liquid.

Reported Uses

Many body builders believe the steroid nature of the ingredients in gamma oryzanol has activity in the body similar to anabolic steroids. This activity includes increased release of growth hormone and increased production and release of testosterone. Not enough research has been conducted in this area. Some research does not support these claims and may actually show an opposite effect. (3) One study with body builders noted that participants who took 30 mg/day of gamma oryzanol for 8 weeks had an increase in body weight and strength. (4) Another study with weight-trained males who consumed 500 mg/day of gamma oryzanol for 9 weeks did no better in strength and performance than the men who did not take any gamma oryzanol. (5) More research is needed before accurate conclusions can be made.

Studies in animals and humans have shown that gamma oryzanol may help lower elevated cholesterol levels. (6) , (7) , (8) This benefit is apparently the result of a combination of effects including reduced cholesterol absorption, increased conversion of cholesterol to bile acids, and an increased excretion of those bile acids. (9) , (10)

Japanese studies suggest that gamma oryzanol may be useful in treating the symptoms of menopause. In one study, 13 women who had undergone a hysterectomy, which is the equivalent of a surgical menopause, were instructed to take 100 mg of gamma oryzanol three times daily. Over half of the women reported a 50% reduction in menopausal symptoms such as hot flashes. (11) Another study gave 40 women 300 mg of gamma oryzanol daily for 4 to 8 weeks. On a survey, 80 to 85% of the women felt that their symptoms had "generally recovered." (12)

Other research in Japan indicates that gamma oryzanol has anti-ulcer activity and it may also be helpful for other problems of the digestive tract. (13) These effects may be due to gamma oryzanol’s ability to decrease gastric acid secretion. (14)

Toxicities & Precautions

Introduction

[span class=alert]Be sure to tell your pharmacist, doctor, or other health care providers about any dietary supplements you are taking. There may be a potential for interactions or side effects.[/span]

General

This dietary supplement is considered safe when used in accordance with proper dosing guidelines.

Pregnancy / Breast Feeding

To date, the medical literature has not reported any adverse effects related to fetal development during pregnancy or to infants who are breast-fed. Yet little is known about the use of this dietary supplement while pregnant or breast-feeding. Therefore, it is recommended that you inform your healthcare practitioner of any dietary supplements you are using while pregnant or breast-feeding.

Age Limitations

This supplement should not be used with children unless as recommended by a physician.

References

  1. View Abstract: Scavariello EM, Arellano DB. Gamma-oryzanol: an important component in rice bran oil. Arch Latinoam Nutr. Mar1998;48(1):7-12.
  2. View Abstract: Ishihara M, Ito Y, Nakakita T, et al. Clinical effect of gamma-oryzanol on climacteric disturbance -on serum lipid peroxides. Nippon Sanka Fujinka Gakkai Zasshi. Feb1982;34(2):243-51.
  3. View Abstract: Wheeler KB, Garleb KA. Gamma oryzanol-plant sterol supplementation: metabolic, endocrine, and physiologic effects. Int J Sport Nutr. Jun1991;1(2):170-7.
  4. Bucci LR, et al. Effect of ferulate on strength and body composition of weightlifters. J Appl Sci Res. 1990;4:104-109.
  5. View Abstract: Fry AC, Bonner E, Lewis DL, et al. The effects of gamma-oryzanol supplementation during resistance exercise training. Int J Sport Nutr. Dec1997;7(4):318-29.
  6. View Abstract: Scavariello EM, Arellano DB. Gamma-oryzanol: an important component in rice bran oil. Arch Latinoam Nutr. Mar1998;48(1):7-12.
  7. View Abstract: Nakayama S, Manabe A, Suzuki J, et al. Comparative effects of two forms of gamma-oryzanol in different sterol compositions on hyperlipidemia induced by cholesterol diet in rats. Jpn J Pharmacol. Jun1987;44(2):135-43.
  8. View Abstract: 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. May2004;:1-11.
  9. View Abstract: Seetharamaiah GS, Chandrasekhara N. Effect of oryzanol on cholesterol absorption & biliary & fecal bile acids in rats. Indian J Med Res. Dec1990;92:471-5.
  10. View Abstract: Sakamoto K, Tabata T, Shirasaki K. Effects of gamma-oryzanol and cycloartenol ferulic acid ester on cholesterol diet induced hyperlipidemia in rats. Jpn J Pharmacol. Dec1987;45(4):559-65.
  11. Murase Y, Iishima H. Clinical studies of oral administration of gamma-oryzanol on climacteric complaints and its syndrome. Obstet Gynecol Prac. 1963;12:147-9.
  12. View Abstract: Ishihara M, Ito Y, Nakakita T, et al. Clinical effect of gamma-oryzanol on climacteric disturbance -on serum lipid peroxides. Nippon Sanka Fujinka Gakkai Zasshi. Feb1982;34(2):243-51.
  13. View Abstract: Ichimaru Y, Moriyama M, Ichimaru M, Gomita Y. Effects of gamma-oryzanol on gastric lesions and small intestinal propulsive activity in mice. Nippon Yakurigaku Zasshi. Dec1984;84(6):537-42.
  14. View Abstract: Mizuta K, Itaya K. Effects of gamma-oryzanol on gastric secretions in rats. Nippon Yakurigaku Zasshi. Mar1978;74(2):285-95.