Rice Bran and Why It Might Help Prevent Cancer
A grain of rice may look boring or unexciting, but to a group of scientists in Colorado, who are looking extremely closely at each grain, it may hold exceptional powers. In fact, experts are now exploring the real possibility that rice bran might help prevent cancer.
What is rice bran?
If you were to slice a grain of rice and examine it under a microscope, you would see there are several layers. Rice bran is the highly nutritious layer between the inner white rice grain and the outer hull, and it is also a byproduct of the process that converts brown rice to white rice. In fact, you can buy rice bran as a food product or supplement.
Rice bran is a rich source of fiber and a variety of bioactive molecules, including but not limited to:
- Vitamin E, a potent antioxidant
- Beta-sitosterol, a phytosterol that helps lower cholesterol
- Ferulic acid, an antioxidant
- Tricin, a flavonoid, which has antioxidant properties
- Polyphenolics, a broad term for literally thousands of different plant nutrients, some of which have been shown to have potent disease-fighting properties
- Gamma-oryzanol, a component that was shown in a recent study to inhibit tumor growth in mice
- Various minerals
One negative concerning rice bran is that it also contains arsenic.
New rice bran research regarding cancer
At the University of Colorado Cancer Center, researchers under the lead of Elizabeth P. Ryan, PhD, assistant professor in the Department of Environmental and Radiological Health Sciences at the CSU Animal Cancer Center, have uncovered cancer prevention properties in rice bran. The challenge, they note, is sifting through the many bioactive molecules.
According to Ryan, "There's a delicate balance of bioactive components in rice bran that together show anti-cancer activity." Among that anti-cancer activity is an ability to inhibit the spread and growth of cancer cells, trigger cell death (also called apoptosis) in malignant cells, and change cell cycle progression.
In the past, scientists have tried to isolate these substances, but Ryan noted it now appears that "it's the synergistic activity of multiple components in the whole food that should be studied." That's a tall order, given that there are more than 100,000 varieties of rice, and many of them have a unique combination of bioactive molecules.
It appears Ryan and her team are up for the challenge, and one reason is the importance of the work. She noted that working with rice bran "has the potential to have a significant impact on cancer prevention for the global population."
Part of that work includes an ongoing clinical trial in which they are evaluating the impact of rice bran in colon cancer survivors. In any case, it appears there's much work to be done in the search for how rice bran might help prevent cancer.
Henderson AJ et al. Chemopreventive properties of dietary rice bran: current status and future prospectives. Advances in Nutrition: An International Review Journal 2012; 3(5): 643
Kim SP et al. Dietary rice bran component gamma-oryzanol inhibits tumor growth in tumor-bearing mice. Molecular Nutrition & Food Research 2012 Jun; 56(6): 935-44