Avoid Alcohol, or at least be temperate in enjoying it. The evidence is pretty strong that consuming more than 3 or 4 drinks per week will increase your breast cancer risk. Specifically, studies show that women who consume 2 to 5 drinks per day have a 41 percent higher risk of getting breast cancer than women who don't drink at all.
Alcohol Serving Sizes:
1 serving = 12 oz. of beer, 5 oz. of wine, 1.5 oz. of hard liquor