Researchers studied a group of prostate cancer patients.
Those patients were told to not eat meat or cheese, spend 30 minutes a day exercising and do yoga and meditation everyday.
The men also skipped conventional treatment including surgery and radiation.
After three months, the men had changes in activity in about 500 genes -- including 48 that were turned on and 453 genes that were turned off.
"My latest biopsy, they couldn't' find any cancer cells at all. I'm not ready to say I'm cured of cancer. They just can't find it any more," said Jack McClure, patient.
Learn more about this study in the Proceedings of the National Academy of Sciences.