Other Risk Factors

Factors That May Lower Breast Cancer Risk

Pregnancy before age 18, early onset of menopause, and surgical removal of the ovaries before age 37 are all associated with a lower-than-average breast cancer  risk. Breastfeeding may also lower breast cancer risk.

Factors NOT Linked to Breast Cancer

Factors that have not been found to be related to breast cancer include coffee or caffeine consumption, antiperspirants, underwire bras, abortion or miscarriage, and breast implants.

Risk Factors Under Investigation

Scientists are still investigating whether environmental pollution increases breast cancer risk. Some studies have suggested that women who are using birth control may have very slight increased risk of developing breast cancer, though that risk disappears after stopping them for 10 years or more. Still other studies show no relationship. Similarly, some studies suggest that diets high in soy, which contains naturally occuring estrogens, may increase breast cancer risk, while other studies suggest that higher levels of soy intake may lower breast cancer risk. Some studies suggest that green tea may lower breast cancer risk. More research is needed and is underway to confirm these findings.