One in eight women will have an encounter with breast cancer in her lifetime. The only dietary factor with a proven connection to increased breast cancer risk is alcohol consumption. And it takes relatively little alcohol to boost that risk. As little as one drink a day can provide a double digit increase in the chance of getting the disease. Three or more servings of alcohol per day gives you the same risk as a daily pack of cigarettes.
A serving is 12 ounces of beer, 4 ounces of wine or a shot (1.5 ounces) of liquor.
Alcohol increases production of the hormone estrogen. Estrogen increases are behind 80 percent of breast cancers. Toxic alcohol also creates another toxin -- acetaldehyde -- as it is metabolized by the body. That second toxin has been shown to alter DNA and breast tissue in younger drinkers, leading to increased cancer risk later in life.
More than 100 studies 1920-2014 have conclusively linked alcohol consumption to increased breast cancer risk. A consensus panel formed by the American Institute for Cancer Research (AICR) in 2007 concluded: "The evidence on cancer justifies a recommendation not to drink alcoholic drinks" ... a recommendation still maintained by the organization.