Alcohol and Risk of Breast Cancer
In this issue of JAMA, Chen and colleagues report findings from the Nurses’ Health Study exploring the relationship between alcohol consumption and breast cancer risk. The authors’ principal findings were that the cumulative amount of alcohol a woman consumes during adulthood is the best predictor of her breast cancer risk and that low levels of alcohol consumption (as few as 3 units of alcohol a week) are associated with an increased risk of breast cancer.
In addition, the risk of breast cancer was increased with the quantity consumed; for example,
- women who drank 2 or more units of alcohol per day had a risk of breast cancer approximately 1.5 times higher than women who never consumed alcohol, and their 10-year risk of breast cancer increased by 1.3% (from 2.8% to 4.1%)
- For women who consumed 1 unit of alcohol per day, the risk was approximately 1.2 times higher than expected and their 10-year risk increased by 0.7% (from 2.8% to 3.5%)