Nutrition and cancer prevention.

Of all cancers in the United States, 35% are estimated to be caused by dietary factors and may be preventable. Diets high in fat or calories, for example, are said to be associated with five of the six most common cancers: breast, colorectal, pancreatic, prostatic, and uterine. Conversely, some dietary components such as vitamin A, in fruits and vegetables, and fiber may help protect against certain cancers. Obesity may confer a small risk of breast cancer on a woman, but women with upper body fat localization are at significantly higher risk of developing breast cancer and endometrial cancer.