I have yet to meet a woman who isn't worried about developing breast cancer, the most common female malignancy in the U.S. All breast cancers are not alike and each type carries different preventions and treatments. It is important to know that only 5-10% of breast cancers are hereditary and those cancers generally appear in younger women. For these women, genetic testing, surveilance and risk management (including prophylactic mastectomy) is best covered by a genetics specialist, depending on family history and results of testing.
The 90% majority of other breast cancers can be treated and prevented with 4 medications: Tamoxifen, Raloxifene, and Aromatase inhibitors( Exemestane and Anastozole). These medications each carry their own side effects and affect estrogen receptors or the production of estrogen in the body. Each has been proven in blinded clinical trials to reduce the rate of breast cancer. But no decrease in mortality has been proven to date. The benefits of these meds must be weighed against the risk and side effects. These medications are not prescribed for all women and depend upon her individual risk factors for developing cancer or prior lobular carcinoma in situ (LCIS) or ductal carcinoma in situ (DCIS). (in situ means situated in the original place) Both of these are considered "pre-cancer" and carry a higher incidence of developing breast cancer in these women. The size of the ducts involved and the age of the woman are important considerations for types of therapy. Chemo therapy is not recommended for DCIS or LCIS. Some women opt for mastectomy to decrease further risk and avoid medication.
Obesity and physical inactivity have been shown to have a major impact on breast cancer. A BMI of over 30 increases the risk of postmenopausal cancer, delay in diagnosis, increased complications from surgery and radiation and decreased survival. The mechanisms by which obesity increases breast cancer is complicated.
Drinking even small amounts of alcohol is linked with an increase risk of breast cancer. The effects are not fully understood but alcohol can increase the levels of some hormones such as estrogen and insulin.
The best drink for breast cancer is green tea which contains compounds and antioxidants that reduce breast cancer risk. White button mushrooms (easy to find in the market) beat out other mushroom types for reducing breast cancer. (They block breast tumor estrogen production like the aromatase inhibitors). These six vegetables blocked aromatase inhibitors by 20%: bell pepper, broccoli, carrots, celery, green onions and spinach. But the big winner was mushrooms coming in at a whopping 60-65%. And a small daily serving of flaxseed can drop breast cancer risk by 20% by blocking the inflammatory effects of Interleuken 1. And let's not forget fiber, found in plants, grains and nuts. 20 grams of fiber a day causes a 15% lower risk of breast cancer. The average woman eating an American diet gets only 15 grams of fiber a day. Way too low. (Thank you Dr Greger for this info)
Breast cancer is complicated but nutrition, exercise, maintaining a good weight and limiting alcohol are ways we can all limit our risk.