Beliveau recommends these items only for preventing a first occurrence of cancer. "The primary prevention evidence is really strong," he says. "There is very little evidence yet for treatment of cancer and secondary prevention."
This is generally true for all of the book's advice. Studies that look at whether an intervention -- be it diet, exercise or meditation -- can reduce the risk of a relapse or alter a treatment outcome are rare.
But Servan-Schreiber goes further, recommending them also for after a cancer diagnosis, as a follow-up to conventional treatment and prevention of a relapse.
Still, the dearth of hard data does not stop some doctors from recommending Servan-Schreiber's approaches for cancer survivors.
"None of his recommendations fit that model of randomized, placebo-controlled trials," says Dr. Larry Bergstrom, director of complementary and integrative medicine at the Mayo Clinic Arizona, in Scottsdale. "But everything he advocates in the book, it's what I tell my patients to do every day."
Bergstrom sees the book as empowering for patients: "There are some things you can do for yourself no matter what is going on with your health."
Dr. Richard Schilsky, president of the American Society for Clinical Oncology and an oncologist at the University of Chicago, says that none of the advice would harm a patient.
But the lack of definitive data is why many mainstream oncologists do not hand out specific recommendations (10 servings of blueberries per week, say, or 30 minutes of swimming three times per week) when patients ask about lifestyle changes, Schilsky says.
Adds Dr. Lowell Schnipper, chief of oncology at Beth Israel Deaconess Medical Center in Boston, "just because something makes sense is not a good enough reason to cause a patient to act on it, when you are in a position of authority, advising them. . . . There are so many examples of promising medications that fell apart when looked at under the magnifying glass of the randomized-controlled study."
But Servan-Schreiber thinks waiting for elusive and far-off absolute answers from large clinical trials is institutional resistance at its worst.
"I think it's medical negligence not to give this information to patients, because people will die without this advice and they will not hurt themselves with it," he says.
Certainly, there is soundness to much of his advice. The American Cancer Society, World Cancer Research Fund and American Society of Clinical Oncology all have guidelines encouraging us to eat more produce and less meat, lower our intake of sugar and fat, exercise more, maintain a lean body mass and not smoke.
It's when Servan-Schreiber departs from these generalities that he gets into debatable science.
For example, the only environmental toxins that the American Cancer Society flags for the public to avoid are cigarette smoke and UV radiation from the sun. But Servan-Schreiber, among other things, urges readers to avoid antiperspirants containing aluminum and limit exposure to the electromagnetic radiation emitted by cellphones. Links between these exposures and cancer have been deemed inconclusive so far by the scientific community.
Still, cancer survivors say his advice isn't hard to swallow.
"Whether or not there's a randomized, controlled trial of these things, I'm going to do them anyway," says Diana Chingos, a three-time cancer survivor and head of USC's Norris Cancer Center Survivorship Advisory Council. The cost is minimal, she says -- slightly higher grocery bills, perhaps paying for acupuncture treatment or a yoga class.
"It doesn't hurt, it makes you feel better, and it will help with other things too," Chingos says. "In my mind, there isn't a downside."