5. Smoking

Smoking is harmful to everyone, being responsible for numerous conditions. It is also responsible for a higher risk of suffering from breast cancer, particularly among younger and premenopausal women. “Researchers at the American Cancer Society have found an increased breast cancer risk among women who smoke, especially those who started smoking before they have their first child,” state the American Cancer Society. “Although previous studies have looked at the possible relationship between breast cancer and smoking, they have not settled the controversy within the scientific community. Part of the reason is that while many studies have found a slight increase in risk overall, they have not found that smoking more cigarettes per day or smoking for more years increases the risk further, which is what might be expected.”

Read more about how smoking can be a breast cancer risk factor.