Health: Small Amounts Of Alcohol Can Increase A Woman's Risk Of Developing Breast Cancer, According To New Study

PHILADELPHIA (CBS) -- A warning for women who drink alcohol, even just a little bit. 3 On Your Side Health Reporter Stephanie Stahl has more on how women who drink less than six alcoholic beverages a week could be increasing their risk of breast cancer by 15 percent.

Tracy Richards, like many women, enjoys an occasional drink.

"Probably one, two, maybe three on a Friday night," said Tracy.

Doctors have known that alcohol increases the risk of breast cancer, but the new research that tracked 100,000 women over 30 years found even light drinking increased the odds.

"Even small doses of alcohol about three to six drinks a week increase the risk of breast cancer slightly. These risks have to be kept in context, which is they're still not huge elevations of risk," said Dr. Susan Domchek, Oncologist with Penn's Abramson Cancer Center. She says the risk was found with any kind of alcohol.

The research only found an association, not proof that alcohol causes cancer.

"It's felt to be because of it's interactions with estrogen and how all the works," said Dr. Domchek.

Researchers also found an increased risk for women who drank when they were younger or older.

Doctors say women with a history of breast cancer may want to limit alcohol, but other studies have also shown drinking can help fight heart disease.

"It's complicated. That's why it's important to weight the pros and cons," said Dr. Domchek.

Researchers also found heavier drinkers, women who had at least two drinks per day, increased their risk of developing breast cancer by 51 percent, compared to women who never drank alcohol.

Reported by Stephanie Stahl, CBS 3