That old notion that a single glass of wine a day is somehow good for you having been thoroughly debunked, researchers are zeroing in on what ills, exactly, so-called “moderate” drinkers may expect. Breast cancer, as it turns out, is the prime danger.

The risk is not minimal, either. Drinking the equivalent of a small glass of wine or beer a day – 10 grams of alcohol – increases pre-menopausal breast cancer risk by 5 percent and post-menopausal breast cancer risk by 9 percent. For most Americans, a standard drink is 14 grams of alcohol.

The new, major meta-study by the American Institute for Cancer Research (AICR) and the World Cancer Research Fund (WCRF) evaluated and reviewed the research of 119 studies worldwide. It included data on 12 million women and 260,000 cases of breast cancer, indexing diet, weight and exercise.

Along with the bad news for the adult beverage crowd, the report showed that:

• Being overweight or obese increases the risk of post-menopausal breast cancer, the most common type of breast cancer;
• Mothers who breastfeed are at lower risk for breast cancer;
• Greater adult weight gain increases risk of post-menopausal breast cancer.

The good news, such as the report had any, is that pre-menopausal women who regularly engage in vigorous exercise have a 17 percent lower risk and post-menopausal women had a 10 percent lower risk of developing breast cancer compared to those who were the least active. Ratchet the activity down a mite – engage in moderate activity, such as walking and gardening – and you stand to benefit from a 13 percent lower risk when compared to the most versus least active women.

Other data from the studies highlighted the connection between breast cancer and diet. Non-starchy vegetables appear to lower the risk for estrogen-receptor negative breast cancers. Diets high in carotenoids – for example kale, carrots and spinach – and calcium also lower your risk for breast cancer.

"Wherever you are with physical activity, try to nudge it up a bit, either a little longer or a little harder. Make simple food shifts to boost protection – substitute veggies like carrots, bell peppers or green salad for chips and crackers and if you drink alcohol, stick to a single drink or less," said Alice Bender, MS, RDN, AICR's Head of Nutrition Programs. "There are no guarantees when it comes to cancer, but it's empowering to know you can do something to lower your risk."

The review was published in Cancer Epidemiology Biomarkers & Prevention.