A Diet for Cancer?
The Dean Ornish solution.
What's the Evidence? continued...
And though there is little research suggesting that exercise or stress management will affect prostate cancer, there is some data suggesting that these lifestyle changes can have a positive impact on other types of cancer. In a study published May 1, 1997, in the New England Journal of Medicine, researchers found that women who were more physically active were less likely to develop breast cancer than were less-active women.
For Ornish colleague Peter Carroll, MD, a urologist at the University of California, San Francisco, the evidence was enough to convince him that this approach was worthy of more thorough study. "This is a group of men who are at low risk because their cancers grow slowly, if at all," he says. "If lifestyle changes can make a difference -- particularly given the other benefits of such changes -- then we would have another treatment option for a substantial number of men."
In fact, as many as 10% to 15% of all men diagnosed with prostate cancer might be candidates for this approach, according to Carroll. This size of this group has convinced the U.S. Army to participate in a larger clinical trial with as many as 3,000 men, which should start this fall. "Given the data, I think that lifestyle changes hold a good deal of promise for the treatment of prostate cancer," said Colonel Judd Moul, MD, director of the Department of Defense's Center for Prostate Disease Research.
It's hard to find a prostate cancer expert who will criticize the notion of a lifestyle-induced remission. Consensus seems to hold that the epidemiological evidence amounts to a good reason to test this hypothesis, and that Ornish and his colleagues, by setting up a randomized, controlled trial, are taking the right course to validate the theory.
Still, not all urologists are as enthusiastic as Moul and Carroll. Some take issue with watchful waiting itself. William Catalona, MD, professor of surgery at Washington University in St. Louis and a leading prostate cancer expert, believes that this approach is really nothing more than a delaying tactic based on outdated information. "About five years ago there was data coming out of Sweden suggesting that watchful waiting was as good as surgery, particularly in older men with early-stage cancer," he says. But, Catalona adds, "We haven't seen any follow-up since then. I think watchful waiting causes some men to postpone effective therapy so long as to miss their window of opportunity for successful treatment."
But the major criticism is the same one as for Ornish's anti-heart-disease regimen: that the program is too draconian. "The dietary change is much too difficult for all but the most committed person to stick to," says Catalona. Both Ornish and Moul, not surprisingly, disagree. When threatened with cancer, they say, people become motivated to make changes that might otherwise have seemed unthinkable.