According to the Mayo Clinic, research shows that lifestyle changes can decrease the risk of breast cancer, even in women at high risk. To lower your risk:

Limit alcohol. The more alcohol you drink, the greater your risk of developing breast cancer. The general recommendation — based on research on the effect of alcohol on breast cancer risk — is to limit yourself to no more than one drink a day, as even small amounts increase risk.

• Breast-feed. Breast-feeding might play a role in breast cancer prevention. The longer you breast-feed, the greater the protective effect.
• Limit postmenopausal hormone therapy. Combination hormone therapy may increase the risk of breast cancer. Talk with your doctor about the risks and benefits of hormone therapy. You might be able to manage your symptoms with nonhormonal therapies and medications. If you decide that the benefits of short-term hormone therapy outweigh the risks, use the lowest dose that works for you and continue to have your doctor monitor the length of time you’re taking hormones.