Many studies show drinking alcohol increases the risk of breast cancer. A pooled analysis of data from 53 studies found for each alcoholic drink consumed per day, the relative risk of breast cancer increased by about seven percent [148]. Women who had two to three alcoholic drinks per day had a 20 percent higher risk of breast cancer [148].
Alcohol may increase breast cancer risk in several ways.
Alcohol, estrogen and breast cancer risk
Alcohol can change the way a woman's body metabolizes estrogen (how estrogen works in the body), causing blood estrogen levels to rise. These higher estrogen levels may in turn, increase the risk of breast cancer [50,149-150].
Learn more about estrogen and breast cancer risk.
Alcohol, folic acid and breast cancer risk
Drinking alcohol can reduce blood levels of the vitamin folic acid. Folic acid plays a role in copying and repairing DNA. Low levels of folic acid may make it more likely that DNA is incorrectly copied when cells divide. Such errors can lead cells down a pathway to become cancerous.
No one should drink a lot of alcohol. For those who do drink some alcohol, getting enough folic acid (often called folate on nutrition labels) may help reduce the extra breast cancer risk linked to drinking alcohol [151-153]. Although not all studies show this benefit [154-157], folic acid is part of a healthy diet. You can get folic acid through a multivitamin or foods such as oranges, orange juice, green leafy vegetables and fortified breakfast cereals.
Updated 11/02/11
