July 16, 2015 | 2 minute read

Research clearly shows that alcohol increases risk for breast cancer overall. Now, a study published this week in the International Journal of Cancer finds that drinking alcohol increases risk for nearly all breast tumor types, especially when women start drinking as young adults. The risk is modest, but it shows one way women can take steps to lower their risk.

Using data from the European Investigation into Nutrition and Cancer (EPIC) study, researchers included 335,000 women from ten European countries and of those,11,576 participants had breast cancer diagnoses after an average of 11 years follow-up. Data on participants included BMI, waist to hip ratio, smoking status, physical activity, education level and diet information. The authors calculated how much alcohol women drank over their life, based on surveys the women filled out on what they drank in their 20s and beyond. About 15% of the women drank more than one alcoholic drink daily.

Drinking alcohol did up risk for most tumor types, including the most common tumors (those sensitive to estrogen-progesterone: ER+/PR+)  and the most aggressive (triple negative, not sensitive to these hormones: ER-/PR-/HER2-). Compared to women who drank on average almost nothing to about half a glass per day, risk increased by 12% for those who consumed 1-2 drinks  daily and 25% for more than 3 drinks daily.

Using models, the authors also calculated the effects when women started drinking before their first pregnancy to those who began later, and found that women who start drinking before their first pregnancy were more likely to develop breast cancer decades later. This supports other studies that show drinking alcohol during adolescence and as young women may increase breast cancer risk, the authors say, because the breast tissue may be more sensitive to alcohol carcinogens.

AICR’s recommendation on alcohol is, if you drink, women should consume no more than 1 standard drink per day, men, no more than 2. One standard drink is 5 ounces of wine, 12 ounces of regular beer or 1 1/2 ounces of liquor. Learn more about the research on lifestyle and breast cancer prevention. In addition to breast cancer, alcohol increases risk for oral, esophageal, liver and colorectal cancers.

For some delicious and colorful alternative beverages to alcohol, check out our summer drinks slideshow.

The study was funded by the International Agency for Research on Cancer, World Cancer Research Fund and government agencies from European countries (see study for full list.)