Thirty men diagnosed with early prostate cancer were enrolled in the study. The men were predominantly white (84 percent), with an average age of 62.3 years, and an average PSA score of 4.8 nanograms per milliliter (ng/ml). Their Gleason scores -- another measure of the severity of the cancer -- were an average of six.
All of the men had already declined immediate surgery, hormonal therapy or radiation. Instead, they chose to have their tumors periodically monitored to ensure that they remained slow-growing.
The lifestyle interventions began with a 3-day residential retreat, followed by weekly telephone consultations and a one-hour group support session each week. The study participants were provided all of their food and were asked to follow a plant-based diet containing about 10 percent of calories from fat. They were also told to walk for 30 minutes a day, six days a week.
Additionally, the study volunteers practiced stress management for 60 minutes a day. Stress management techniques included yoga-based stretching, breathing exercises, meditation, imagery, and progressive relaxation. The study volunteers were also given additional soy, three grams of fish oil, 100 units of vitamin E, 200 milligrams of selenium and 2 grams of vitamin C daily.
The researchers compared genetic expression from baseline samples to those taken after three months of study intervention and found positive changes in more than 500 genes, according to Ornish.
"I thought younger people with milder disease would show the most improvement, but neither age nor disease severity made as much difference as adherence," said Ornish. That means that the more people are able to change, the better. And, these findings suggest that you're never too old to make changes that can positively affect your health.
"It's encouraging to see that by going on a very low-fat diet that you can change gene expression in the prostate itself, but just because changes can happen, you don't yet know if it would mean anything for cancer risk," said Dr. Simon J. Hall, director of the Deane Prostate Health and Research Center, and the chairman of urology at Mount Sinai School of Medicine in New York City.
