For example, a previous report by the same group, published in June 2007 in the Journal of Clinical Oncology, showed that diet made a big difference in reducing breast cancer mortality.
There is another point of view in the diet and cancer world: Perhaps everything that we think is good for us is actually bad.
"Good food causes cancer," says Dr. David Jenkins, professor of nutritional sciences at the University of Toronto.
"Let me explain the hypothesis: Cancers also feed on good foods," he says. "So giving cancer lots of calcium, omega-3 fatty acids, folic acid, and so on can actually help it grow."
Dr. Jenkins believes that the way out of the good-food-causes-cancer quagmire is to reduce the amount of calories we take in -- drastically.
"The solution is not cherry-picking good foods," he explains, "but choosing things that have anti-nutritive values, and keeping your calories low. If you eat 20 percent fewer calories, then you are truly lean and mean. You're also lean and mean as an environment for tumor growth."
But the worst solution to this problem, Jenkins says, is to switch over to a junk-food diet.
"Good food will kill you," he says. "But bad food will kill you quicker."
Outside of an extreme diet, there are other factors that may reduce both the risk of cancer's first time occurrence, as well as its recurrence.
"The strongest influence on risk of first occurrence of breast cancer is diet at the time breasts are developing -- that is during puberty," says Carla Wolper, of the Obesity Research Center at St. Luke's Hospital in New York City.
"A healthy body weight and low to moderate fat intake during puberty, particularly a diet low in animal fat, is recommended."
Even if women can't go back in time to rescue their eating habits in their teenage years, there are still things they can do today to reduce the risk of breast cancer.
"A healthy diet needs to be a marathon, not a sprint," says Ayoob, who recommends a diet high in fruits, vegetables , and whole grains, along with a focus on low-fat and fat-free dairy foods.
"I also want [my patients] to be a healthy weight and exercise daily," he says. "I want my patients to have a decent shot at preventing cancer recurrence, but they shouldn't have to trade cancer survival for heart disease."
Other experts agree that a long-term view is the best one to take.
"Consider, as an analogy to cancer prevention, fire prevention," says Dr. David Katz, director of the Prevention Research Center at the Yale University School of Medicine.
"So, for example, not smoking -- or having a smoke detector -- would be useful fire prevention strategies. But not smoking, or having a fire detector, would do nothing to help put a fire out! And neither would do much to prevent the recurrence of a fire that had not been put out altogether, either."