Exercise.  Evidence is growing that exercise can reduce breast cancer risk.  The American Cancer Society recommends engaging in 45-60 minutes of physical exercise 5 or more days a week.  Alcohol consumption.  Studies have shown that breast cancer risk increases with amount of alcohol a woman drinks.  Alcohol can limit your liver’s ability to control blood levels of the hormone estrogen, which in turn can increase risk.  Smoking is associated with a small increase in breast cancer risk.

Source:  NCI  2019