Regular physical activity
Active women of all ages are at reduced risk of breast cancer compared to women who do not exercise.
The exact amount of physical activity needed to reduce your risk is not yet clear. However, studies have shown that one and a half to four hours per week of brisk walking (or equivalent) reduces the risk of breast cancer in post-menopausal women. And the more exercise you do, the bigger the benefits in lowering your risk.
Having children is associated with a decreased risk of breast cancer. The more children women have, the more their risk of breast cancer appears to be reduced.
Among women who have had children, having them at a younger age (less than 30 years) is associated with lower breast cancer risk.
Breastfeeding for a total of 12 months or longer can slightly reduce your breast cancer risk.