Long-term drinking of alcohol may make breast cancer more likely to occur in women who are less than 50 years.

This study investigated the theory that alcohol consumption is associated with increased risk of breast cancer in women. A total of 1,506 Brazilian women volunteered for this study and were assessed for their alcohol drinking habits and incidence rate of breast cancer. 

Researchers discovered that alcohol consumers who were less than 50 years with a drinking history of at least 10 years had high tendency to suffer from breast cancer compared to occasional or non-consumers of alcoholic beverages. The study concluded that "Regular alcohol consumption increases the risk of breast cancer mainly among women less than 50 years old."