Comprehensive Guide to Gamma-Oryzanol

Gamma-OryzanolDr. James Meschino DC, MS, ND
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General Features
Gamma-Oryzanol (esters of ferulic acid) is a growth-promoting substance in grains and is isolated from rice bran oil for use as a supplement. In 1970 Gamma-Oryzanol was approved as a medicinal treatment to lower cholesterol and triglycerides (Japan).1 As far back as the 1960's, Gamma-Oryzanol was shown to be effective in the treatment of menopausal symptoms, including hot flashes, and subsequent studies have supported these findings.
Orally administered Gamma-Oryzanol is converted in the body to free ferulic acid
Supplementation Studies and Clinical Application
1. Menopausal Symptoms
Supplementation with Gamma-Oryzanol (150 mg, twice per day) has been shown to reduce the secretion of leutinizing hormone (LH) by the pituitary and promote endorphin release by the hypothalamus.3 Hot flashes and other menopausal symptoms (profuse sweating, mood changes) result indirectly from the over-secretion of leutinizing hormone, which is attempting to initiate the start of another ovulatory cycle. The lack of response by the immature egg cells in the ovaries in menopause results in an over-secretion of FSH (follicle stimulating hormone) and LH by the pituitary, contributing to the onset of hot flashes and related symptoms.
Clinical trials involving menopausal women and women who had their ovaries surgically removed, have revealed that 67-85 percent of women treated with Gamma-Oryzanol have experienced a significant reduction in menopausal symptoms.
2. Cholesterol and Triglyceride Lowering (Hypo-Lipidemic Effects)
A number of clinical traits reveal that 300 mg per day of Gamma-Oryzanol supplementation can lower cholesterol by 8-12 percent and triglycerides by approximately 15 percent in subjects with elevated lipid levels.
Gamma-Oryzanol supplementation increases the conversion of cholesterol to bile acids, increases bile acid excretion, and inhibits the absorption of cholesterol from the intestinal tract to the bloodstream.
These are important considerations for post menopausal women as heart disease is the most common cause of death in women over 50 years of age in North America. The decline in circulating estrogen levels with menopause predisposes postmenopausal women to a rise in blood cholesterol and the development of atherosclerosis. This is, in part, due to the fact that estrogen increases the number of LDL- cholesterol receptors on body cells, enabling the body to remove LDL-cholesterol from the bloodstream very effectively.
Dosage
Menopausal Symptoms: 300 mg per day, taken in divided doses (ie. 150 mg, twice per day).
Hypolipidemic Effects: 300 mg per day, taken in divided doses (i.e. 150 mg, twice per day).

Adverse Side Effects and Toxicity
Toxicity studies on animals demonstrate that it is a very safe compound. No significant side effects have been reported in human trials or experimental studies.

Drug-Nutrient Interactions
There are no reported drug-nutrient interactions for gamma-olyzanol.
References
1. Murray M. Encyclopedia of Nutritional Supplements. Rocklin, CA: Prima Publishing; 1996. p. 332-5.
2. Fujiwara S, et al. Mass fragmentographic determination of ferulic acid in plasma after oral administration of gamma-oryzanol. Chem Parm Bull 1982;30:973-979.
3. Yamauchi J, et al. Inhibition of LH secretion by gamma-oryzanol in rat. Horm Metabol Res 1981;13:185.
4. The Merk Manual. 16th edition. Merck & Co. 1992. p. 1767-8.
5. Murase Y, Iishima H. Clinical studies of oral administration of gamma-oryzanol on climacteric complaints and its syndrome. Obtet Gynecol Prac 1963;12:147-9.
6. Ishihara M. Effect of gamma-oryzanol on serum lipid peroxide levels and climacteric disturbances. Asia Oceania J Obstet Gynecol 1984;10:317.
7. Yoshino G, Kazumi T, Amano M, et al. Effects of gamma-oryzanol on hyperlipidemic subjects. Curr Ther Res 1989;45:543-52.
8. Yoshino G, et al. Effects of gamma-oryzanol and probucol on hyperlipidemia. Durr Ther Res 1989;45,975-82.
9. Sasaki J, et al. Effect of gamma-oryzanol on serum lipids and apolipoproteins in dyslipidemic schizophrenics receiving major tranquilizers. Clin Ther 1990;12:263-8.
10. Seetharamaiah GS, Chandrasekhara N. Effect of oryzanol on cholesterol absorption and biliary & fecal bile acids in rats. Ind J Med Res 1990;92:471-5.
11. Sakamoto K, et al. Effects of gamma-oryzanol and cycloartenol ferulic acid ester on cholesterol diet induced hyperlipidemia in rats. Jap J Pharmacol 1987;45:559-65.
12. Gura T. Estrogen: key player in heart disease among women. Science 1995;269:771-3.
13. Colditz G, Willett W, Stampfer M, Rosner B, Hennekens C. Menopause and the risk of coronary heart disease in women. New Engl J Med 1987;316:1105-10.
14. Tamagawa M, Otaki Y, Takahashi T, Otaka T, Kimura S, Miwa T. Carcinogenicity study of gamma-oryzanol in B6C3F1 mice. Food Chem Toxicol 1992;30:49-56.
15. Tamagawa M, Shimizu Y, Takahashi T, Otaka T, Kimura S, Kadowaki H, et al. Carcinogenicity study of gamma-oryzanol in F344 rats. Food Chem Toxicol 1992;30:41-8.