Prostate cancer is, according to the Centers for Disease Control and Prevention (CDC), the most common form of cancer among men in the United States. In 2009, over 200,000 men were diagnosed with prostate cancer, and over 28,000 died from the disease. Worldwide we see similar incidences of prostate cancer, but in Asian societies scientists noticed a difference. In the West, prostate cancer is likely to progress, expanding and developing more and more tumors, but in Asian countries it is not. This begs the question, "Why?"
A study published last month in the journal Cancer Prevention Research may provide the answer to this question – a high-fiber diet. Asian cultures tend to have a diet high in dietary fiber, from rice and other grains, and Western societies do not. The study, performed at the University of Colorado Cancer Center, was conducted on mice, but the results are interesting enough that scientists and doctors are excited about how the findings of the study may apply to humans.
What happens when you feed mice with prostate cancer a high-fiber diet?
To find out the answer to this question, Komal Raina, PhD, and his fellow researchers fed the mice (in which prostate tumors had been induced) a diet high in inositol hexaphosphate (IP6), one of the major components of high-fiber diets. A control group of mice with prostate tumors were fed a normal diet, without the IP6. Then the researchers used magnetic resonance imaging (MRI) scans to monitor the tumors to see whether and how fast the tumors were spreading in each group.
As Raina says, "The study’s results were really rather profound. We saw dramatically reduced tumor volumes, primarily due to the anti-angiogenic effects of IP6." Feeding the mice a diet high in the active ingredient of high-fiber diets kept the prostate cancer tumors from spreading by preventing the formation of new blood vessels that tumors require to supply themselves with nutrients. Deprived of these nutrients, the tumors could not grow.
The researchers also found that IP6 slowed the rate at which these prostate cancer tumors metabolized glucose, another factor that allows cancer to grow and spread. When speculating about the possible reasons for this significant effect of IP6 on cancer growth, the researchers suggest that the IP6 may cause a reduction in the production of a protein called GLUT-4, which is instrumental in transporting glucose.
Asked to sum up his findings, Raina says, "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. Asian cultures get IP6 whereas Western cultures generally do not."
Diet also plays a part in preventing prostate cancer
Another review study published in the Journal of Human Nutrition and Dietetics suggests that diet can be a major factor in the prevention of prostate cancer. These researchers found that a diet low in fat and red meat but high in fruits and vegetables resulted in significantly reduced rates of prostate cancer. The study authors wrote about their findings, "Although not conclusive, results suggest that general dietary modification has a beneficial effect on the prevention of prostate cancer. In patients with prostate cancer, dietary therapy allows patients to be an active participant in their treatment."
So again diet has been found to be a factor that can reduce one’s risk of developing prostate cancer, or if a case of prostate cancer has already developed, it supports one’s ability to slow its spread and survive the disease. And all as the result of eating more sensibly, the way most of our mothers told us to, "Eat your fruits and vegetables and lots of whole grains." It looks as if Mom was right.