(RxWiki News) It is certainly not uncommon for women to try alcohol during their teen years. And partying during college is almost the norm. But alcohol use during these years could be dangerous for some young women.
Drinking also elevated the risks of proliferative benign breast disease, a condition that increases breast cancer risks and includes everything from abnormal tissue development and cysts to changes in breast tissue.
Not drinking before pregnancy may be an important way young women can lower their lifetime risks of breast cancer.
"As a young woman, limit your drinking."
Ying Liu, MD, PhD, from the Washington University School of Medicine in St. Louis, MO, and colleagues analyzed data from Nurses’ Health Study II (NHSII), which studied female registered nurses from 1989 to 2003.
The authors noted in the study background that the International Agency for Research on Cancer considers alcohol to be linked with invasive breast cancer.
No research had been conducted regarding alcohol consumption among young women between the time of their first period and first pregnancy.
“This time in life before the first pregnancy is when breast cells are most susceptible to the effects of alcohol, a known carcinogen and cause of breast cancer,” Graham A. Colditz, MD, DrPH, Niess-Gain Professor of Surgery at Washington University School of Medicine and one of the study’s authors, told dailyRx News.
Women involved in the NHSII were between the ages of 25 and 44 years. They completed mailed questionnaires about their medical history, reproductive history and lifestyles.
They were asked about alcohol consumption at four different ages: 15-17 years, 18-22 years, 23-30 years and 31-40 years.
Participants reported the types of alcohol they drank — beer, wine and liquor together — in quantities ranging from none or less than one drink per month to 40 or more a week.
One drink was defined as one bottle or can of beer, a 4-ounce glass of wine or a shot of liquor. The estimated content of ethanol per alcoholic drink was 12 grams.
After exclusions due to lack of information or cancer occurrence, 91,005 women were included in the final analysis of breast cancer risk.
Among this group, 1,609 cases (1.76 percent) of breast cancer and 970 (1.06 percent) cases of benign breast disease occurred during the study period.
The researchers found that women who drank an average of 10 grams of alcohol a day between menarche (start of menstruation) and first pregnancy had a 13 percent increased risk of developing breast cancer.
Drinking this amount of alcohol, which equates to six drinks a week, after the first pregnancy increased breast cancer risks by 11 percent, the study found.
Breast cancer risks increased with the quantities of liquor consumed and the more years between menarche and first pregnancy.
Compared to nondrinkers, a woman who became pregnant 10 or more years after her first period had a 26 percent increased risk of breast cancer and an 81 percent higher risk of proliferative benign breast disease.
“With the age at first birth continuing to rise in high-income countries, the adverse effect of alcohol consumption through these years becomes even more evident and more important for prevention,” Dr. Colditz said.
“Alcohol is already a well-demonstrated breast cancer risk factor, but this study gives us a specific time period to focus prevention efforts on,” he continued. “This is the most important time in a woman’s life with regard to breast cancer risk.”
“My key takeaway for public: Young women should reduce their drinking to less than one drink a day, especially during this time period, as a key tool to reduce their life long breast cancer risk," said Dr. Colditz, who is a dailyRx News Contributing Expert.
Findings from this study were published August 28 in the Journal of the National Cancer Institute.
The research was funded by the National Cancer Institute, National Institute of Health. No conflicts of interest were reported.