Can Rice Bran Prevent Occurrence of Cancer?

Cancer is a major public health problem the world over. One in four deaths in the U.S. is due to cancer. According to the Centers for Disease Control and Prevention, 12.7 million people are diagnosed with the ailment each year, and 7.6 million die from it.

Several studies have been done to curb the incidences of cancer.

The latest clinical trial tests conducted at the University of Colorado Cancer Center show how rice bran offers promising cancer prevention properties. Simultaneously, the ongoing clinical trial is testing the effectiveness of rice bran in preventing the recurrence of colon cancer.

"While I have been trained as a molecular toxicologist, I am excited about the opportunities to deliver bioactive, cancer fighting compounds with food, and this has led to my focus now primarily on the multiple drug-like characteristics of rice bran," says Elizabeth P. Ryan, PhD, CU Cancer Center investigator, assistant professor in the Department of Environmental and Radiological Health Sciences at the CSU Animal Cancer Center, and the review's senior author. "There's a delicate balance of bioactive components in rice bran that together show anti-cancer activity including the ability to inhibit cell proliferation, alter cell cycle progression and initiate the programmed cell death known as apoptosis in malignant cells," Ryan says.

Though this trial Ryan and her colleagues have shown how bioactive rice bran derived small molecules include but are not limited to polyphenolics, ferulic acid, tricin, β-sitosterol, γ-oryzanol, tocotrienols/tocopherols, and phytic acid.

"We're working now to tease apart the ratios of these active molecules required for bioactivity and mechanisms. Previous attempts to isolate one or another compound have been largely unsuccessful and so it looks now as if rather than any one compound giving rice bran its chemopreventive powers, it's the synergistic activity of multiple components in the whole food that should be studied."

On working with cancer cell lines and animal models, it was seen that the bioactive components of rice bran act not only within cancer cells but also around the cancer cell in order to create conditions in the surrounding tissues that promote the function of healthy cells while inhibiting the function of cancer cells.

This tissue microenvironment activity includes intervening chronic inflammation that provides a ripe landscape for cancer.

The researchers are evaluating how rice bran may also help to promote an anti-cancer immune response and modulate gut microbiota metabolism for protection against cancer.

"There are well over 100,000 varieties of rice in the world, many with their own unique mix of bioactive components and so one major challenge is to discover the optimal composition for chemoprevention. Another challenge is ensuring that people consistently receive the required daily intake amount or 'dose' needed to demonstrate these chemo-protective effects. That said, rice is an accessible, low-cost food in most places of the world, and so work with rice bran as a dietary chemopreventive agent has the potential to impact a significant portion of the world's population," Ryan says.

The study is presented in the journal, Advances in Nutrition.