NEXT Chapter 5. The risk of getting breast cancer is several times higher in the United States than in many other countries. Thus, it does not seem that most breast cancers are inherited, but rather are due to something about living in the high-risk country. It does not seem to be due to how old the average woman is or the standard of living. Women in Japan have a much lower breast cancer risk, but live just as long as American women and live in just as advanced a country.
Careful studies suggest that the difference in risk is probably due to something about the diet.
It is uncertain whether it is the fat or something that goes along with eating a high-fat diet that increases a woman's risk for getting breast cancer. Some experts say it would help, while others say it might not. Much of the argument is about whether a woman who changes her diet in the middle of her life, after years of eating a high fat diet, would reduce her breast cancer risk. No one knows for certain. It might help and it is unlikely to hurt, although making such a major change is often difficult.