For decades, we've known that a woman's risk of osteoporosis increases if she is white or Asian, 50 years or older, thin or have small frame, consume diet low in calcium and vitamin D, smoke, or drink too much alcohol. What was not known until recently is how fast and widespread bone loss occur in postmenopausal women. New statistics have medical experts scrambling for answers.

In United States, osteoporosis and low bone mass are now believed to be a major public health threat for 44 million Americans aged 50 and older. By 2010, that number is expected to increase to over 52 million. Nearly half of all women and a quarter of men aged 50 and older will suffer an osteoporosis-related fracture in their remaining lifetime.

Currently, the disease affects an estimated ten million Americans - eight million women and two million men. Another 34 million Americans, most of whom are women, have low bone mass, placing them at increased risk of osteoporosis. In addition, osteoporosis is responsible for 1.5 million fractures, and the direct health care costs associated with these fractures are estimated at $18 billion per year. That's right; billion with a "B".

Hip fractures account for 300, 000 hospitalizations each year. About 20% of senior citizens who suffer a hip fracture die within a year of sustaining the fracture, and another 20% of all hip-fracture patients will be in a nursing home within one year. These numbers are worrisome, to say the least.

Although there is no clear explanation for this upsurge in the incidence of osteoporosis among older women, poor diets and sedentary lifestyle are suspected to play a role. In fact, a recent National Health and Nutrition Examination Survey concluded that many Americans particularly women, ethnic minorities, and the socially disadvantaged are not meeting the current recommendations for adequate calcium and vitamin D intake through diet alone or with calcium and vitamin D supplements.

Another factor implicated in the steep rise in osteoporosis cases is too much coffee drinking among older women. There is growing evidence that caffeine decreases blood calcium levels by increasing calcium excretion in urine, and this increases the risks of fracture and osteoporosis. In a study published in 2001, for example, postmenopausal women who consumed 300 milligrams of caffeine a day lost more bone mass in the spine compared to women who consumed less than 300 milligrams a day.

So, is there something a woman can do to slow down bone loss? Many experts believe that the results of these new surveys amount to a wake-up call to all women to take immediate steps to protect themselves against the debilitation of osteoporosis. The current health advice is that older women should begin by ensuring that they meet their daily calcium and vitamin D requirements through diet alone or with supplements.

They should also get regular weight-bearing exercise. Examples of exercises that provide bone health benefits include walking, jogging, racket sports, dancing, stir climbing, and skating. For bone health, any physical activity that puts stress or strain on bone will help strengthen the bone and increase its density. On the other hand, exercises such as biking and swimming may not provide the same benefits because, during these exercises, the bone is supported rather than being put under stress.

Of course, older women must take care of smoking. In addition to having a negative effect on a woman's bones, there is a number of health problems associated with smoking. Cigarette smoke produces toxins in the body and increases a person's risk for chronic diseases like heart disease, cancer, diabetes, and osteoporosis.

The bottom line is that numbers do not lie, and the current numbers for osteoporosis suggest a silent epidemic among postmenopausal women. However, older women should not feel helpless; there are steps they can take to fight back. These steps include getting enough calcium and vitamin D, getting a regular weight-bearing exercise, moderating coffee drinking, and avoiding smoking. But, they must get going. The time is now; tomorrow may be too late.