A new study links the amount a woman drinks in the years prior to having children to breast cancer years later. The Journal of the National Cancer Institute released the study results online Aug. 28, showing a double-digit increase in breast cancer risk for women who drank as little as one drink daily prior to conception. The results were independent of drinking after first pregnancy.
"The risk increased by 11 percent for every 10 grams a day of intake, about six drinks per week," said study author Dr. Ying Liu of Washington University School of Medicine in St. Louis. A drink, or 10 grams of alcohol, is a 12 oz. beer, a 4 oz. glass of wine or a1.5 oz. shot of hard liquor.
Researchers also discovered an increase in benign breast disease, a non-cancerous condition which accounts for 80 percent of breast lumps. These benign lumps do increase the risk of breast cancer by 500 percent. The more alcohol consumed between the onset of the first menstrual period and the first pregnancy, the greater the risk for both benign breast disease and breast cancer, the study reported.
The results are a warning in favor of alcohol moderation – or abstinence – during adolescence and early adulthood when the breasts are developing new tissue. "Breast tissues are particularly susceptible to environmental exposures between [the onset of menstruation] and first pregnancy because they undergo rapid cellular proliferation," Liu said. "Our results suggest that alcohol intake before the first pregnancy consistently increases the risk.” The association between drinking before first pregnancy and breast cancer appeared to be stronger for women who had a greater interval of time between the first menstrual cycle and first pregnancy, which is to say that older first-time moms carry a higher risk if they were daily drinkers.
Earlier research reported in the Journal of the American Medical Association (JAMA) in 2012 also connected an increase in breast cancer risk to how much a woman drinks. (see related examiner.com article, “The pink link between alcohol and breast cancer”) The earlier study did not, however, look specifically at drinking before having children. Changes to the breast during pregnancy are related to a lower susceptibility to cancers.
One in eight women, drinkers and non-drinkers, will develop breast cancer in her lifetime.