Breast health is tricky. "The first thing to remember is that reducing the risk of breast cancer is not like reducing the risk of heart disease or diabetes," says Dr. Susan Love, physician and author of Dr. Susan Love's Breast Book. "We don't have a list of rules that, if you follow them, can guarantee you won't get breast cancer." Rules, perhaps not. But strong suggestions, very much so. Here are seven of the most important:

Exercise isn't just good for your waistline -- it's good for your breasts as well. In fact, more than 35 studies show a link between regular exercise and reduced breast cancer risk. How much do you need? "Three or four hours of activity a week," says Leslie Bernstein, a breast cancer prevention expert at the University of Southern California's Keck School of Medicine. The more vigorous the exercise, the better.

Recent studies show that drinking even one glass of wine or beer a day can increase breast cancer risk by about 10 percent. The greater the alcohol consumption, the greater the risk.

In 2002, researchers found that women who took hormone replacement therapy containing both estrogen and progestin increased their breast cancer risk by 24 percent. That led to a precipitous drop in HRT use which, in turn, led to a precipitous drop in rates of estrogen-sensitive breast cancer. Virtually all doctors now agree that long-term HRT use is unsafe, but many think short-term use is probably justified in women with severe menopausal symptoms, says Dr. Wendy Chen, an oncologist and epidemiologist at Boston's Dana-Farber Cancer Institute. "But minimize the time you're on it. Ideally, that should be less than a year or two," she says.

Weight gain is linked to higher breast cancer rates. If losing weight proves too difficult, Chen suggests a still-worthy goal: "Try not to gain weight after menopause," she says, when your risk of breast cancer is highest.

A small percentage of women are at extremely high risk of developing breast or ovarian cancer as a result of two genetic mutations, called BRCA-1 and BRCA-2. If you have a strong family history of breast or ovarian cancer, ask your doctor about genetic counseling and testing. The information can clarify your risk and help you evaluate your options.

Annual mammograms are important for women 40 and older and can help catch the disease early, when it's easier to treat. Federal law requires that you receive your mammogram report in the mail, written in terms a layperson can understand. "If you don't get one from the center, call," says Love.

"If we're going to prevent breast cancer and not just treat it," says Love, "we're going to have to start demanding research that looks into prevention." One way to do that is to visit the Web site of the National Breast Cancer Coalition, stopbreastcancer.org, and click on "Join Our Email List." You'll receive regular alerts that can help you become involved in the cause. Or find a breast cancer action group near you by contacting a local hospital.