Teens and young women who average about one alcoholic drink per day between their first period and giving birth for the first time have a higher risk of breast cancer according to a new study.
The research was published online on Aug. 28 by the Journal of the National Cancer Institute.
Having about one drink per day also increased the risk of benign (not cancer) breast disease. This is important because being diagnosed with benign breast disease -- called proliferative benign breast disease -- is linked to a higher risk of breast cancer in the future.
While many studies have found a link between drinking and breast cancer risk in adult women, few studies have looked at how alcohol affects breast cancer risk in adolescent girls and young women.
In this study, called the Nurses’ Health Study II (NHS II), researchers are looking for links between personal health and lifestyle factors and a variety of health risks. More than 116,670 female nurses between the ages of 25 and 44 completed a comprehensive questionnaire about their health and lifestyle when they enrolled in the study in 1989. Since then, the women have regularly provided updated information on their health, diets, and lifestyles.
This study is a prospective study, which means the women were followed over time and the researchers tracked who did and didn’t develop breast cancer. The results of prospective studies are usually given more weight than the results of retrospective studies, which look back into the histories of people diagnosed with a particular disease or condition to find things they may have had in common. Most previous studies looking at the relationship between alcohol and breast cancer have been retrospective studies.
For this latest analysis, the researchers looked at information from more than 91,000 women in the study. The women were asked how much they drank at certain ages:
- 15 to 17 years old
- 18 to 22 years old
- 23 to 30 years old
- 31 to 40 years old
Answers ranged from none or less than one drink per month to more than 40 drinks per week. One drink was equal to one bottle of beer, one glass of wine, or one shot of liquor.
The researchers also asked the women how much they drank in the past year and how much they drank before and after their first pregnancy.
Health records showed that 1,609 cases of breast cancer and 970 cases of benign breast disease were diagnosed in the women.
Women who averaged about one drink per day between their first period and giving birth to their first child had a 13% higher risk of breast cancer and a 15% higher risk of benign breast disease.
Compared to women who didn’t drink, women who drank between their first period and first full-term pregnancy were:
- more likely to be older when they had their first child
- more likely to have a family history of breast cancer
“More and more heavy drinking is occurring on college campuses and during adolescence and not enough people are considering future risk,” said Graham Colditz, M.D., associate director for cancer prevention and control at the Siteman Cancer Center at the Washington University School of Medicine, who co-authored the study. “But, according to our research, the lesson is clear: If a female averages one drink per day between her first period and her first full-term pregnancy, she increases her risk of breast cancer by 13%.”
Limiting or avoiding alcohol is a good idea for every girl and young woman who wants to do all she can to lower her risk of breast cancer. You may want to talk to your sisters, daughters, granddaughters, and other young women in your life about the effects alcohol can have on health, especially breast health.
For many of us, drinking is social. But cutting back on alcohol doesn’t mean cutting back on seeing your friends and family. If you’re not sure you can go to an event and not have a drink, keep your health in mind. Remember that you’re keeping your risk of breast and other cancers as low as possible.
For more tips on how to be social and not drink, visit the Breastcancer.org Drinking Alcohol page in the Breast Cancer Risk Factors pages.