1. Eat and drink what you want. Diet doesn't play a big role in breast cancer.
False. Being overweight increases risk: Fat cells produce estrogen, the hormone that fuels many breast tumors, so the fewer you have, the better. Watch those cocktails as well, since overdoing alcohol is bad for your liver, which helps to regulate estrogen levels. (Have fewer than five drinks a week.)
2. Exercise is one of the most effective ways to lower your risk.
True. All those workouts torch estrogen-producing fat. And you can't start too early. A new study in The Journal of the National Cancer Institute found that girls and women who exercise regularly between 12 and 35 are significantly less likely to develop breast cancer before menopause than those who aren't as active.
3. Fertility drugs increase breast cancer risk.
False. Although these drugs affect hormone levels, research shows they don't increase the likelihood of breast cancer in otherwise healthy women, according to a Danish study of more than 54,000 (the exception: women with active breast cancer genes).
4. Family history is the biggest risk factor for this disease.
False. A woman's odds are higher than average if a close relative (from either side of the family) was diagnosed, but age is actually the strongest predictor. In fact, the majority of breast cancer patients are the first in their families to get it-and 80 percent are diagnosed after 65. For more on protecting yourself from breast cancer, log on to breastcancer.org or cancer.gov.
5. Breastfeeding is good for your baby -- and for your breasts.
True. Nursing lowers hormone levels, but you have to keep it up for several months to get the protective benefit. Consider it incentive!