Gaynor says that eating fish rich in omega-3 fatty acids is also healthful because it supports proper immune function and lowers a woman's risk of heart disease and diabetes.
The American Cancer Society warns against eating too many of these fatty foods: "Diets high in fat tend to be high in calories and may contribute to obesity, which in turn is linked with an increased risk of several types of cancer."
Beans and whole grains
Women who consume a high-fiber diet probably boost their life expectancy.
"A high-fiber diet is associated with lower overall mortality in breast cancer patients," said Dr. Keith Block, medical-scientific director at the Block Center for Integrative Cancer Treatment in Skokie, Ill.
Block says fiber is beneficial because it can help women control their appetite and may decrease the number of calories they consume. Achieving and maintaining a healthy weight, particularly after menopause, is widely viewed as one factor that influences survival.
Which is why Estabrook at the Comprehensive Breast Center is offering that nutrition class in the first place.
"When you look at cancers, most are caused by weight gain," she said. "The fatter you are, the more estrogen circulates in your body, and when there's more estrogen, the risk of breast disease increases.
"But cancer survival is not just about eating one kind of fruit or vegetable. It's about making the right lifestyle choices, including exercise. Diet is one part of a larger picture."