Last updated: Apr 21, 2008
Your breasts now:
In your 30s, your chest is made up mostly of breast tissue. But as you enter this decade, the percentage of fat in your breasts increases, breast specialist Holly Smedira says. Fats less likely to withstand the effects of gravity, so your breasts will start to droop and sag.
 
Your most common concern:
Breast cysts. As breasts change from their lactational state, fluid can be trapped in the ducts, causing fluid-filled cysts, Smedira explains. They are harmless (though sometimes painful) and can be evaluated by ultrasound and then aspirated if they are large or uncomfortable. They wont increase your future risk of cancer, Smedira says.


Best breast-cancer-screening strategy:
Annual mammograms. Starting at age 40, “its crucial to get a mammogram every year, especially since the test has only about 80 percent sensitivity in younger, premenopausal women,” stresses Julia Smith, MD, director of the New York University Cancer Institute Breast Cancer Screening and Prevention Program. “This way, if an early-stage cancer is missed one year, it most likely will be caught the next.”

See: "What to expect if you're having a mammogram."

Its also important to do monthly at-home breast checks and see your doctor for yearly breast exams, says Rachel Brem, MD, vice chairman of radiology and director of breast imaging at the George Washington University Medical Center in Washington, D.C. A must for premenopausal women: Find a center that offers digital mammography, which takes an electronic image of your breasts and stores it directly into a computer, Brem says. A recent National Cancer Institute (NCI) study found that digital mammography picks up more cases of cancer, but only in women who are premenopausal and/or have dense breasts.

Best breast-saving move:
Stand up straight. “As a woman gets older, her back muscles weaken, and she tends to slouch, which gives her breasts the appearance of hanging down to her belly button,” Archer says. “If you strengthen your upper-back and torso muscles, youll have a nice open chest and shoulder line, which will help make your breasts look perkier.”

Try the Back–Shoulder Blade Squeeze:
Stand with shoulders relaxed and arms at your sides. Hold the end of an exercise band in each hand in front of your body. Exhale as you squeeze shoulder blades together, keeping your shoulders relaxed, torso stable, and wrists flat; inhale as you return arms to starting position. Do 8–12 reps, working up to 1 minute. And increase band resistance as you get stronger.

Good news!
Premenopausal women who get three servings of low-fat dairy every day and pop a calcium supplement with vitamin D daily reduce their risk of breast cancer by about 40 percent, according to a Harvard study.