High Fiber Diet Could Inhibit Prostate Cancer Spread

The January, 2013 issue of Cancer Prevention Research published findings of the University of Colorado Cancer Center which reveal a protective effect for inositol hexaphosphate (IP6) against the metastasis of prostate cancer in an animal model of the disease. Inositol hexaphosphate is a compound that is abundant in high fiber diets, which are more prevalent among non-Western cultures that, while having a similar incidence of prostate cancer as Westerners, have a significantly lower risk of the cancer progressing.

"Researchers have long been looking for genetic variations between Asian and Western peoples that could explain the difference in prostate cancer progression rates, but now it seems as if the difference may not be genetic but dietary," stated lead author Komal Raina, PhD. "Asian cultures get IP6 whereas Western cultures generally do not."

Rajesh Agarwal and colleagues studied the effects of IP6 in TRAMP (transgenic adenocarcinoma of the mouse prostate) mice, which are genetically modified to develop metastatic prostate cancer. Four week old mice were given water that contained 1 percent, 2 percent, 4 percent or no IP6 for 24 weeks. Magnetic resonance imaging (MRI) of the prostate was periodically conducted to assess prostate volume and tumor vascularity.

The team found a reduction in prostate tumor metastasis in animals that received higher concentrations of IP6 that was due in part to the ability of the compound to reduce new blood vessel formation. They discovered a decrease in a glucose transporter protein known as GLUT-4 in the prostates of treated mice, and observed that IP6 decreased glucose metabolism and membrane phospholipid synthesis. "The study's results were really rather profound," Dr Raina commented. "We saw dramatically reduced tumor volumes, primarily due to the antiangiogenic effects of IP6."

"These findings show that oral IP6 supplement blocks growth and angiogenesis of prostate cancer in the TRAMP model in conjunction with metabolic events involved in tumor sustenance," the authors conclude. "This results in energy deprivation within the tumor, suggesting a practical and translational potential of IP6 treatment in suppressing growth and progression of prostate cancer in humans."