Gamma Oryzanol
What is it? Overview Usage Side Effects and Warnings

What is Gamma Oryzanol?

Gamma oryzanol is a mixture of substances derived from rice bran oil, including sterols and ferulic acid. It has been approved in Japan for several conditions, including menopausal symptoms, mild anxiety, stomach upset, and high cholesterol. In the US, it is widely used as a sports supplement, as well as for reducing cholesterol. However, there is no meaningful evidence supporting the use of gamma oryzanol for any of these purposes.

Like many other vegetable oils, rice bran oil appears to improve cholesterol profile . 1 Preliminary evidence, including small double-blind, placebo-controlled trials , suggests that the gamma oryzanol portion of rice bran oil may contribute an additional cholesterol-lowering benefit beyond the effects of the fatty acids. 2 Gamma oryzanol is thought to work by impairing cholesterol absorption in the digestive tract. 3 Additionally, gamma oryzanol has antioxidant properties. It has been hypothesized that antioxidants can help protect against heart disease, cancer, and other illnesses; however, it must be kept in mind that gigantic studies looking for such benefits with the antioxidants vitamin E and beta-carotene have returned negative results. 4 Gamma...

Safety Issues

In the late 1970s, a batch of rice bran oil was contaminated by PCBs (polychlorobiphenyls), resulting in the poisoning of more than 2,000 people. This led to studies on the safety of gamma oryzanol products. On balance, the results of these investigations suggest that gamma oryzanol, when taken at normal doses, is nontoxic and noncarcinogenic. 5 However, the maximum safe dosages for young children, pregnant or nursing women, or those with severe liver or kidney disease have not been established.