The scientific link between alcohol and breast cancer is strong, but most of the research backing it has been done in white women, not diverse groups of women.
Now, in a new analysis published in Cancer Epidemiology, Biomarkers & Prevention, scientists find the same risk among black women. They studied more than 22,000 women in the African-American Breast Cancer Epidemiology and Risk Consortium, in which the women answered questionnaires about their alcohol habits. Their answers were correlated with records of breast cancer diagnoses. Women who reported drinking more than seven drinks a week had a higher risk of breast cancer of nearly all types compared to women who drank less. Women who drank 14 or more alcohol beverages weekly had a 33% higher chance of developing breast cancer than women who drank four or fewer beverages a week.
The findings strengthen what’s already known about alcohol as a risk factor for breast cancer. Researchers believe alcohol can boost estrogen levels, which then feed certain types of breast cancer. In some cases, alcohol may also damage DNA in breast cells, causing them to grow abnormally.