Health experts have long suspected Asian men have lower prostate cancer death rates than those of Western nations because of a genetic advantage. But new research suggests genes have less to do with it than diet. In fact, a compound found in high-fiber foods — more common in Asian cuisine — prevents cancer growth.
The discovery, reported by University of Colorado Cancer Center researchers in the journal Cancer Prevention Research, suggests a high-fiber diet may have the clinical potential to block progression of the disease in patients diagnosed in early stages. The study, which is based on tests of laboratory mice, indicates a major component of high-fiber diets — called IP6 (inositol hexaphosphate) — effectively shuts down prostate tumors by preventing them from making new blood vessels they need to grow and spread.
"The study's results were really rather profound. We saw dramatically reduced tumor volumes, primarily due to the … effects of IP6," said Komal Raina, research instructor at the Skaggs School of Pharmaceutical Sciences.
The CU researchers noted prostate cancer rates in Asia are similar to those in the West, but it tends to progress and spread more in non-Asian men. To examine the effects of IP6 on tumors growth, Raina and colleagues compared cancerous mice fed the compound to those that were not, then monitored MRI scans to track the progression of the disease.
The results showed IP6 kept prostate tumors from making the new blood vessels they need to supply themselves with energy and hindered their ability to process glucose.
"Researchers have long been looking for genetic variations between Asian and Western peoples that could explain the difference in prostate cancer progression rates,” Raina said. “But now it seems as if the difference may not be genetic but dietary. Asian cultures get IP6 whereas Western cultures generally do not."