Young Women Who Drink Face Higher Risk of Breast Cancer, Study Claims

There's a new reason for young female drinkers to slow down. Photo: GettyHappy hour just got a little sad. A new study claims that the more alcohol young women consume between the age of their first period and their first pregnancy, the higher their risk of developing breast cancer. Just one drink per day during that invincible-feeling time, in fact, raises the risk by 13 percent.

More on Shine: Even Moderate Drinking Linked to Increased Cancer Risk

“Alcohol itself is already a well-documented breast pathogen,” lead study author Ying Liu, of Washington University School of Medicine in St. Louis, told Yahoo Shine. “But there was no data showing that the timing of drinking is also an important issue. Our study is the first to show this.”

The findings, if heeded, could have a major impact on young women's lives. “More and more heavy drinking is occurring on college campuses and during adolescence, and not enough people are considering future risk,” noted study co-author Graham Colditz, of the Siteman Cancer Center at Barnes-Jewish Hospital, also in St. Louis.

In May, a Harvard Medical School study of nearly 1,000 college students found that the young women were binge-drinking more frequently than their male counterparts, meaning they had more than three drinks per day on a fairly regular basis.

For the latest study, published online on Thursday in the Journal of the National Cancer Institute, researchers analyzed data on more than 91,000 mothers in the U.S. who were tracked over a 20-year period.

In addition to the cancer link, the study found that for every drink a young woman consumes daily, her risk of benign breast disease increases by 15 percent. And while it is noncancerous, the presence of benign breast disease can increase a woman's breast cancer risk by up to 500 percent, Liu noted.
 
So why do the findings make sense? First, because of the time period in question, between the onset of menstruation, or menarche, and a first pregnancy. “That time period is very important for a woman in terms of breast cancer,” Liu said. “It’s when the breast tissue is particularly susceptible to environmental exposures, because of the cell proliferation during that time. It’s more resistant later.”

That risk increases with the introduction of alcohol. Drinking poses a potential health risk on its own, but introducing it during a biologically vulnerable period in a woman's life is like throwing fuel on the fire.

Pooled data from more than 50 studies on booze and breast cancer, according to the Susan G. Komen organization, shows that women have a 7 percent increased risk of the disease from every one drink consumed daily. That jumps to 20 percent with three drinks consumed daily. Though scientists are unsure about why alcohol is such a risk, Liu said some theorize that it causes an increase in estrogen levels, which leads specifically to estrogen-receptor positive cancers (in which estrogen is what's causing the tumor to grow).

Either way, she added, the findings of this latest study tell us clearly “that lower alcohol consumption among young women might be a good strategy in reducing the risk of breast cancer.”

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