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Supplements

gamma-oryzanol

What Is It?
Health Benefits
Forms

Dosage Information

Guidelines for Use

General Interaction

Possible Side Effects

Cautions

References

Evidence-Based Rating Scale

 

What Is It?

For commercial purposes, gamma-oryzanol is extracted from rice bran oil although it also appears in grains such as barley and corn. In Japan, this concentrated mixture of ferulic acid and other compounds is commonly added to foods and beverages. The bulk of research on gamma-oryzanol's health benefits has been done in Japan, although supplements are now available in the United States as well. Gamma-oryzanol is a member of a group of plant-based sterols similar to cholesterol known as phytosterols.  Please see the WholeHealthMD article on phytosterols.

Health Benefits

Apparently acting on the brain's control of digestion, and possibly through a direct effect on the stomach, gamma-oryzanol may help to ease heartburn and other digestive-system discomforts. In a 2008 animal study, gamma-oryzanol reduced inflammation from colitis and could possibly have the same effect in humans.  More studies are needed. (1).

Gamma oryzanol has been used for treating symptoms of menopause but no human studies support its effectiveness for this use. Studies using injections of gamma-oryzanol into animals indicate the supplement suppresses luteinizing hormone (LH), the hormone that stimulates ovulation. (2) More studies are needed to determine any effectiveness in humans.

Gamma-oryzanol may even help to lower cholesterol.  A 2005 study of mildly hypercholesterolemic (high cholesterol concentration in the blood) men showed that rice bran oil containing various amounts of gamma-oryzanol improved lipoprotein levels. (3) Gamma-oryzanol in combination with omega-3 fatty acids, vitamin E and niacin has also been shown to improve lipid profiles and inflammation in patients with dyslipidemia, a condition that is a risk factor for atherosclerosis. (4) In addition, gamma-oryzanol has Antioxidant properties that could potentially protect heart vessels from free-radical damage. (5)

Body-builders have tried gamma-oryzanol supplements to boost their performance, but clinical trials indicate that this is fruitless. In a 1997 study, male weight trainers who took gamma-oryzanol supplements (500 mg a day for nine weeks) failed to perform better than participants taking a Placebo. Nor were levels of various hormones, including endorphins or testosterone (a male Hormone), affected in any way. (6) 

In a study of patients with hypothyroidism (underactive thyroid), gamma-oryzanol was shown to reduce serum levels of thyroid stimulating hormone (TSH), which normally elevate in an effort to stimulate the thyroid to produce more hormone. However, in this study, even though TSH was lowered, levels of the active thyroid hormones were unchanged suggesting that lowering TSH did not actually treat the hypothyroid condition. (7)

Gamma-oryzanol has shown promise in antitumor activity in animal studies.  In a 2003 study, human prostate cancer tissues were implanted in mice and the mice were given gamma-oryzanol in combination with other herbal supplements. Tumor growth was inhibited in the tissue; however, more studies are needed. (8)

Forms

  • Capsules

  • Extract

  • Powder

  • Tablets

Dosage Information

  • For heartburn and acid-related stomach disorders; ulcers, GERD. Take 150mg three times a day until symptoms ease.

  • For elevated cholesterol. Take 300 mg per day or 100mg three times per day. (9)

Guidelines for Use

  • Gamma-oryzanol has been shown to reduce TSH levels in blood and serum. This may interfere with test results for this condition.

  • Gamma-oryzanol in combination with omega-3 fatty acids, vitamin E and niacin has been shown to reduce cholesterol levels in blood and serum.

General Interaction

There are no known drug or nutrient interactions associated with gamma-oryzanol.

Possible Side Effects

There are no known side effects for gamma-oryzanol. (10)

Cautions

  • Gamma-oryzanol appears to be quite safe and free of significant side effects, although more research in humans is needed.

  • People with an underactive thyroid should be aware that gamma-oryzanol can lower levels of thyroid stimulating hormone (TSH) as well as alter test results used to monitor this condition.

  • Because of its apparent effect on hormone levels, pregnant or breast-feeding women should avoid taking gamma-oryzanol in highly concentrated supplement form.

 

References

1.  Islam MS, Murata T, Fujisawa M, Nagasaka R, Ushio H, Bari AM, Hori M, Ozaki H Anti-inflammatory effects of phytosteryl ferulates in colitis induced by dextran sulphate sodium in mice. Br J Pharmacol. 2008 Jun;154(4):812-24.
2.  Wheeler KB, Garleb KA. Gamma oryzanol-plant sterol supplementation: metabolic, endocrine, and physiologic effects. Int J Sport Nutr. 1991 Jun;1(2):170-7
3.  Berger A, Rein D, Schäfer A, Monnard I, Gremaud G, Lambelet P, Bertoli C. Similar cholesterol-lowering properties of rice bran oil, with varied gamma-oryzanol, in mildly hypercholesterolemic men. Eur J Nutr. 2005 Mar;44(3):163-73.
4.  Accinni R, Rosina M, Bamonti F, Della Noce C, Tonini A, Bernacchi F, Campolo J, Caruso R, Novembrino C, Ghersi L, Lonati S, Grossi S, Ippolito S, Lorenzano E, Ciani A, Gorini M. Effects of combined dietary supplementation on oxidative and inflammatory status in dyslipidemic subjects. Nutr Metab Cardiovasc Dis. 2006 Mar;16(2):121-7.
5.  Cicero, AF, Gaddi, A. Rice bran oil and gamma-oryzanol in the treatment of hyperlipoproteinaemias and other conditions. Phytother Res. 2001 Jun;15(4):277-89.
6.  Fry AC, Bonner E, Lewis DL, Johnson RL, Stone MH, Kraemer WJ. The effects of gamma-oryzanol supplementation during resistance exercise training. Int J Sport Nutr. 1997 Dec;7(4):318-29.
7.  Shimomura Y, Kobayashi I, Maruto S, Ohshima K, Mori M, Kamio N, Fukuda H. Effect of gamma-oryzanol on serum TSH concentrations in primary hypothyroidism. Endocrinol Jpn. 1980 Feb;27(1):83-6.
8.  Ng SS, Figg WD. Antitumor activity of herbal supplements in human prostate cancer xenografts implanted in immunodeficient mice. Anticancer Res. 2003 Sep-Oct;23(5A):3585-90.
9.  Sasaki J, Takada Y, Handa K, Kusuda M, Tanabe Y, Matsunaga A, Arakawa K. Effects of gamma-oryzanol on serum lipids and apolipoproteins in dyslipidemic schizophrenics receiving major tranquilizers. Clin Ther. 1990 May-Jun;12(3):263-8.
10. Amended final report on the safety assessment of Oryza Sativa (rice) Bran Oil, Oryza Sativa (rice) Germ Oil, Rice Bran Acid,Oryza Sativa (rice) Bran Wax, Hydrogenated Rice Bran Wax, Oryza Sativa (rice)Bran Extract, Oryza Sativa (rice) Extract, Oryza Sativa (rice) Germ Powder, Oryza Sativa (rice) Starch, Oryza Sativa (rice) Bran, Hydrolyzed Rice Bran Extract, Hydrolyzed Rice Bran Protein, Hydrolyzed Rice Extract, and Hydrolyzed Rice Protein. Int J Toxicol. 2006;25 Suppl 2:91-120

Evidence Based Rating Scale  

The Evidence Based Rating Scale is a tool that helps consumers translate the findings of medical research studies with what our clinical advisors have found to be efficacious in their personal practice. This tool is meant to simplify which supplements and therapies demonstrate promise in the treatment of certain conditions. This scale does not take into account any possible interactions with any medication/ condition/ or therapy which you may be currently undertaking. It is therefore advisable to ask your doctor before starting any new treatment regimen.

Condition

Rating

Explanation

 

 

  

  

Heartburn

 

 

 

  

 

 

 

 

 

Usual practice, opinion, animal studies done, more human studies needed.
 
 

 

  

Acid-Related Stomach Disorders; Ulcers, GERD,

 

 

 

 

 

 

Usual practice, opinion, animal studies done, more human studies needed.

 

 

 

 

 

 

 

 

Elevated cholesterol 

 

 

 

 

 

 

 

 

 

Small studies in rice bran oil and in combination with other supplements show benefit. Favorable patient evidence, more studies needed.

 


Date Published: 04/18/2005
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