The research is the first randomized, controlled trial showing that lifestyle changes may affect the progression of any type of cancer. Study findings are published in the September issue of the Journal of Urology.
The study was directed by Dean Ornish, MD, clinical professor, and Peter Carroll, MD, chair of the Department of Urology, both of the University of California, San Francisco, and the late William Fair, MD, chief of urologic surgery and chair of urologic oncology, Memorial Sloan-Kettering Cancer Center.
The research team studied 93 men with biopsy-proven prostate cancer who had elected not to undergo conventional treatment for reasons unrelated to this study. The participants were randomly divided into either a group who were asked to make comprehensive changes in diet and lifestyle or a comparison group who were not asked to do so.
After one year, the researchers found that PSA levels (a protein marker for prostate cancer) decreased in men in the group who made comprehensive lifestyle changes but increased in the comparison group. There was a direct correlation between the degree of lifestyle change and the changes in PSA. Also, they found that serum from the participants inhibited prostate tumor growth in vitro by 70 percent in the lifestyle-change group but only 9 percent in the comparison group. Again, there was a direct correlation between the degree of lifestyle change and the inhibition of prostate tumor growth.
Participants in the lifestyle-change group were placed on a vegan diet consisting primarily of fruits, vegetables, whole grains, and legumes supplemented with soy, vitamins and minerals. They participated in moderate aerobic exercise, yoga/meditation, and a weekly support group session. A registered dietitian was available for consultation, and a nurse case manager contacted the participants once a week for the first three months and weekly thereafter.
None of the lifestyle-change participants had conventional prostate cancer treatments such as surgery, radiation, or chemotherapy during the study, but six members of the comparison group underwent conventional treatments because their disease progressed. Patients in the lifestyle-change group also reported marked improvements in quality of life.
According to Carroll, "This study provides important new information for men with prostate cancer and all men who hope to prevent it. This is the first in a series of trials attempting to better identify the exact role of diet and lifestyle in the prevention and treatment of prostate cancer."
"Changes in diet and lifestyle that we found in earlier research could reverse the progression of coronary heart disease may also affect the progression of prostate cancer as well. These findings suggest that men with prostate cancer who undergo conventional treatments may also benefit from making comprehensive lifestyle changes," said Ornish, who is also founder and president of the non-profit Preventive Medicine Research Institute. "This adds new evidence that changing diet and lifestyle may help to prevent prostate cancer."
The researchers are continuing to follow these patients to determine the effects of their changes in diet and lifestyle on morbidity and mortality.
The research was funded by the Department of Defense via the Henry Jackson Foundation, the Prostate Cancer Foundation, the National Institutes of Health, the UCSF Prostate Cancer Specialized Program of Research Excellence, the Buckshaum Family Foundation, Highmark, Inc., the Koch Foundation, the Ellison Foundation, the Fisher Foundation, the Gallin Foundation, the Resnick Foundation, the Safeway Foundation, the Walton Family Foundation and the Wynn Foundation.