To Avoid Osteoporosis, Start Early

It's easy to think of bone loss as something that women need not worry about until they've joined the blue-hair set. That would also be wrong. True, more than half of all American women who live past 65 are affected by osteoporosis. But the damage begins much earlier. In the six years after menopause, a woman can lose 20 percent or more of her bone mass—enough to set her up for crippling fractures in her 60s.

By taking action in her 40s and 50s, a woman stands a much better shot of keeping the bone she's got. "Within one year of your last period, you've lost half of what you're going to lose," says Robert Recker, director of the Creighton University Osteoporosis Research Center in Omaha. "You can preserve bone mass way better than you can restore it if it's lost."

Fortunately, the first steps are simple and cheap: Take 1,200 milligrams of calcium and 1,000 mg of vitamin D (there's little downside to using supplements), and get 30 minutes of weight-bearing exercise each day; two 15-minute walks count. Since the body builds new bone in response to stress, this save-the-bone program is the perfect excuse to play more tennis or perhaps shoot hoops. (You might pick an activity that's good for the whole family, like double-dutch jump rope; a study published last April found that children who jumped off a box 100 times during thrice-weekly PE classes had significantly more bone mineral density eight years later than children who didn't make the leaps.)

Some people should consider escalating their response. Women who are small and thin face a greater risk of osteoporosis, as do those who are inactive, smoke or drink heavily, or ingest a lot of caffeine. Family history matters, too. So a person with one or more of these risk factors should consider getting a central DEXA scan, an X-ray that measures bone mineral density in the hip and spine. The quick, noninvasive test is the only way to measure bone density. A middle-aged woman found to have either low bone density or osteoporosis can take medication to slow bone loss, but the choices are far from simple.

For years, doctors offered one effective treatment to keep women from losing bone after menopause—hormone replacement therapy. Estrogen protects bones by slowing bone loss, and it can be particularly useful in stopping the accelerated bone loss immediately after menopause. But in the past few years, data from the Women's Health Initiative have shown that estrogen plus progestin, a drug often combined with it, increases the risk of breast cancer, heart attack, and stroke.

Nevertheless, some endocrinologists say that estrogen by itself remains a valid option for slowing bone loss, particularly if it's taken for a decade or less and by women who don't have a family history of breast cancer. Women can also take raloxifene, which protects bone by slowing bone thinning and causing increased bone thickness.

The third big option in medication is bisphosphonates, a group of drugs that slow bone loss, reducing the risk of spine or hip fractures by about half over two to four years. They've been associated with rare side effects, including jaw pain and osteonecrosis of the jaw, in which areas of jawbone die. Almost all osteonecrosis cases occur in cancer patients taking the drug intravenously, whereas most cancer-free patients take it orally. The National Osteoporosis Foundation recommends that people taking biphosphonates tell their dentist and get regular dental checkups to help reduce risk.