Drinking alcohol—whether wine, beer, or liquor—is a confirmed risk factor for breast cancer, causing over 100,000 new cases globally each year and accounting for nearly one in ten cases worldwide. The International Agency for Research on Cancer (IARC) classifies alcoholic beverages as a Group 1 carcinogen, placing them in the same high-confidence cancer-causing category as tobacco. The risk rises with consumption: even light drinking (1-3 drinks per week) increases the risk, while drinking two units daily elevates the risk by 13% compared to one unit daily. Heavier drinking not only increases the likelihood of developing the disease but also raises the chances of dying from it and experiencing a recurrence after treatment. While the exact biological mechanism remains unclear, scientists suspect alcohol raises estrogen levels and damages mammary DNA, with risk amplified by factors like folate deficiency or hormone replacement therapy. Globally, alcohol consumption leads to roughly 144,000 breast cancer diagnoses and 38,000 deaths each year, with the majority occurring among moderate or heavy drinkers.