Introduction
Cancer of the breast occurs in women of all races and appears to have happened throughout history. It is slowly increasing in frequency all over the western world. In Britain about 24,000 new cases are diagnosed each year, and 15,000 deaths are certified as due to the disease. This suggests that about a third of all cases die of some other cause, with no evidence of further cancer in their bodies. These women could reasonably be claimed to have been cured of their breast cancer. To put it another way, 1 woman in 14 will contract breast cancer during her lifetime and 1 in 21 will die of it (Cancer Research Campaign 1988).
Britain tops the international table, alas, with a death rate five times that of Japan. Now that there is a lot of information on migrant populations, we know that Japanese who immigrate to America soon share American death rates for most common cancers. While this has not yet come true for breast cancer, there is evidence to suggest that it will. Thus the information from migration suggests that environmental factors play a large part in the onset of the disease. Despite intensive study, it is disappointing to report that no clear guidance as to how to reduce risk through diet has emerged.
Those factors implicated in the development of breast cancer that can be avoided are obesity and ionizing radiation. Of the remaining risk factors, age is inevitable and some others carry such a small risk that few would wish to change their lives because of them. It may be more important to list some common worries which are presently under investigation and have not been shown to affect significantly the incidence of the disease. They include high fat diet, hormone replacement therapy, oral contraception, alcohol, stress, and benign breast disease.
