Dr. Jean H. Hankin is a researcher and professor of public health with the Epidemiology Program of the Cancer Research Center of Hawaii.
Her review of scientific research on diet and breast cancer was published recently in the Journal of the American Dietetic Association.
Dr. Hankin found the relationship between dietary fat and breast cancer still controversial. Animal studies show that high fat diets increase risks for breast cancer. Yet studies that look at large groups of women produce conflicting results.
Twelve studies show that diets high in fat and low in vitamin C increase breast cancer risk. But three studies, including one of 90,000 nurses, could find no connection between fat and breast cancer.
Ecologic studies show breast cancer is six to eight times higher in North America, northern Europe and Australia than in most Asian and African countries. In addition, breast cancer is more common in countries with higher per person intakes of fat, saturated fat, animal protein and total calories.
Six studies show that high alcohol use, about 40 grams a day, increases risk for breast cancer. That's about three 4-ounce glasses of wine, three 12-ounce beers or 3 ounces of hard liquor.
Several studies indicate soybean products reduce cancer risks, even for premenopausal breast cancer.
The least processed products like tofu, soy milk, tempeh and soy flour retain the most phytochemicals and seem to have the greatest effect, but much more study is needed.
Phytochemicals are a recently discovered group of elements in food that are not vitamins or minerals and contain no calories, but are biologically active and appear to have a cancer preventive effect.
Other apparently protective elements include vitamin A, beta carotene, vitamin E and dietary fiber. Other studies suggest pasta, cereals and vegetables high in vitamin A and C might be helpful.
So what should I eat?
Each of us gambles with our knife and fork daily.
Eating a low-fat diet reduces risks for heart disease and obesity, so we can reduct fat without absolute proof that it prevents breast cancer. Dr. Hankin suggests high-risk women aim for 20 percent of calories from fat. That's about 50 grams a day before menopause, and 40 grams a day after.
To get fiber, vitamins and minerals, aim for two to four fruits, three to five vegetables and six or more grain products daily, at least three of them from whole grains.
Limit alcohol to one or two drinks a day, if at all.
Eat well. Stack the odds in your favor.