Dr. T. Colin Campbell of Cornell University has studied the Chinese diet, which is centered on rice and vegetables, with little meat and no dairy products. The apparent effect is not just a higher age of puberty, but also phenomenally low rates of heart disease, obesity, and cancer. High-fat diets may also encourage the absorption of carcinogens into the body. Researchers have observed, for example, that when the carcinogens in cigarette smoke are absorbed through the lung tissue, they tend to travel along with fats in the blood. It may be that on a low-fat diet, the body is less able to absorb and transport carcinogens.
Evidence suggests that other factors also play important roles.
The mineral selenium, found in grains, helps prevent cancer, as does physical exercise and avoiding alcohol. We can dramatically reduce the toll, not only of breast cancer, but of other cancers as well. A complex and fascinating study by Dr. Daniel Cramer of Harvard University elucidated the relationship between cancer and diet. Dr. Cramer studied hundreds of women with ovarian cancer, and had them record in detail what they normally ate. He compared them to a group of women who were similar in age and other demographic variables but did not develop cancer.