The announcement was made in the early online edition of the Proceedings of the National Academy of Sciences for July 2003. The new results suggest that a molecular defect linked to bone stem cells that help maintain bone health may be contributing to the loss of bone.

Although it has been known that a family history of osteoporosis increases a person's chances of developing the disease, physicians have not been able to accurately predict who would be a victim. New research is bringing us closer to predicting, preventing and perhaps even curing this debilitating and sometimes disfiguring disease.

Osteoporosis literally means porous bone. The disease is characterized by low bone mass and structural deterioration of bone tissue. Those in the later stages of the disease can have spines that are severely compressed and bent with kyphosis or necks that are compressed until the head has sunken into or below the shoulders.

Now considered a major public health threat, osteoporosis is a sly, silent disease that progresses with a creeping collapse of the supporting skeletal framework of the body. Too often the condition is discovered only when a fracture occurs. If the break is minor, the victim is lucky.

A hip fracture can be the fatal finish to a once-active life, particularly when the patient is elderly. This type of fracture results in prolonged immobility, a situation that contributes to further loss of bone in an area already frail. One in four of these patients dies within a year following the hip fracture; curiously, the death rate in men is twice that of women.

Some physicians feel that once a patient's bone is thin enough to result in fractures it will be difficult to reverse the disease process and restore sufficient strength to the bones. The fractures mostly occur in the hip, spine or wrist. So far there is no cure for osteoporosis.

The typical patient with osteoporosis is usually depicted as a Caucasian or Asian woman, small-boned or thin, and postmenopausal. Unfortunately, in actuality, no one is safe. The disease has been found in all ethnic groups and it can strike at any age. One 52-year-old office worker was chagrined to find that, in spite of running 15 to 20 miles per week, she was scored by a bone density test as being at "moderate" risk of fracture.

Smoking and heavy drinking, as well as an inactive lifestyle, low lifetime calcium intake and surgically induced menopause increase the likelihood of bone loss.

Medications prescribed to treat conditions such as rheumatoid arthritis, endocrine disorders (for instance, an underactive thyroid), seizure disorders and gastrointestinal diseases may have side effects that can damage bone and thus lead to osteoporosis. Even over-the-counter medications such as antacids containing aluminum can cause bone loss. Patients should always check with their caregiver about any side effects when medications are prescribed, but seniors should be especially concerned about those that might cause bone loss. A less damaging drug might be able to be used instead. At the very least, bone density should be carefully monitored in seniors on such medications.

In the United States alone, 44 million people have some form of osteoporosis: 10 million already have serious disease (8 million women and 2 million men), and another 34 million (about 55 percent of people over 50) have bone mass low enough to be at risk for fracture. One in two women and one in four men over 50 will have an osteoporosis-related fracture sometime in their lifetime.

Prevention should begin early, according to the National Osteoporosis Foundation, a professional nonprofit organization devoted to the prevention, diagnosis and treatment of osteoporosis. Peak bone density is achieved regularly during childhood and adolescence and is harder to achieve during the later years. This is a good reason to encourage grandchildren to bike-ride or hike or engage in impact exercise or sports (such as tennis, basketball and so on).

To ensure good bone health throughout the adult and senior years, weight-bearing exercise (for example, jogging several times per week) should be maintained well into the elder years. Most experts recommend at least a brisk walk for 20 or more minutes every day. Walter M. Bortz II, M.D., claims in his book, Dare to be 100, that not only is there is no evidence of any damage to the bones of elders due to regular jogging but their bones are in better shape than those of inactive people. Dr. Bortz also states that it is never too late to begin your prevention program, and NOF agrees.

In addition to regular exercise, a diet rich in calcium (recommendations range from 1,000 to 1,300 mg per day) and vitamin D (recommendations range from 400 to 800 IU per day) is usually advised by the experts. However, beware of using as a source of calcium antacids that contain aluminum.

Neal Barnard, M.D., author of Foods that Fight Pain, claims that too much animal protein (meat, poultry, fish, eggs), sodium (salty foods), caffeine and tobacco leach calcium from the blood and bones. He also says that, in the few studies done, sugar has been implicated in calcium loss.

Andrea Dorey is a former AARP chapter president. Contact her at purrenialgreene@aol.com.