Drinking Before First Pregnancy Raises Risk of Breast Cancer: Study | WPN World People News

Drinking even one alcoholic drink a day in the years before a woman's first pregnancy can increase her risk of breast cancer later in life, according to a large new study.

Other research has linked alcohol consumption to increased breast cancer risk, as well as finding that delayed childbearing can increase breast cancer risk.

The new research is thought to be the first to focus on the effect of alcohol intake during the time frame between the start of menstruation and a first pregnancy, the researchers said.

The risk increased by 11 percent for every 10 grams a day of intake, about six drinks per week. These risk values were estimated as compared with nondrinkers.

Drinking about one drink a day also increased the risk for proliferative benign breast disease, a risk factor for breast cancer, by about 16 percent, according to the study.

The researchers analyzed data from more than 91,000 women who took part in the Nurses' Health Study II who had no cancer history when they began. They answered questions on alcohol consumption in 1989 and were followed through 2009 to analyze their risk of breast cancer.

The new study also looked at whether the women contracted benign breast disease, and whether alcohol may have played a role in that condition, in a subgroup of more than 60,000 women who were evaluated from 1991 through 2001.

The researchers found more than 1,600 cases of breast cancer and 970 diagnoses of benign breast disease during the study period.

Drinking alcohol after the first menstrual period and before the first pregnancy was linked with a risk of both, regardless of whether a woman drank after the first pregnancy. The link held after accounting for multiple other risk factors, including family history of breast cancer.

The more the women drank, the higher their risk.

The researchers, however, found only a link between pre-pregnancy drinking and breast cancer risk, not a cause-and-effect relationship.

"Breast tissues are particularly susceptible to environmental exposures between [the onset of menstruation] and first pregnancy because they undergo rapid cellular proliferation," expert said. During pregnancy, however, other cellular changes make the breast tissue less susceptible to cancer.

The results suggest that alcohol intake before the first pregnancy consistently increases the risk of breast cancer and the risk of proliferative [benign breast disease]. Expert speculated that the benign breast disease may be a pathway linking drinking in early life and breast cancer, but not the only route.

It is crucial to put the 11 percent increased risk in perspective.

Overall, a woman's lifetime risk of breast cancer is about one in eight, or 12 percent. If you take the baseline risk -- 12 percent -- and increase that by 11 percent, it is about 13 percent.

The research is another call for moderation, all women in the age category she studied "should reduce their drinking to less than one drink a day, especially before first pregnancy, to reduce their breast cancer risk.

Source: HealthDay News