Healthy Bones, Healthy Bodies
A Honolulu-based doctor shares her tips for keeping bones strong—whether you’re 30 or 90.
About 1.3 million American women suffer from an osteoporosis-related fracture each year. Half of these fractures occur in the spine, one-quarter in the hip and the rest in the wrist and pelvis. We often think of osteoporosis as a disease of aging, and it is—one-third of women who reach the age of 90 suffer from a fracture—but there are also some conditions that predispose younger women to having weaker bones. Building healthy bones is actually a lifelong project. The good news is that osteoporosis is preventable and treatable, through exercise, diet and even medication.
This spring, many women were concerned by the headlines that came out after the release of the Women’s Health Initiative, a seven-year federal study on 36,282 women ages 50 to 79. “Big Study Finds No Clear Benefit of Calcium Pills,” boomed The New York Times. Yikes. Should we toss out the calcium pills? Well, not so fast.
What About Men?
While women suffer from osteoporosis in greater numbers than men, guys aren’t off the hook. In fact, according to the American Academy of Family Physicians, about 30 percent of all hip fractures occur in men. Past the age of 50, one in eight men will have an osteoporosis-related fracture. So if you’re a man age 50 or older, it’s worth discussing bone health with your doctor.
Later in the same Times story, the writer goes on to say, “The study’s investigators emphasized encouraging hints and biological plausibility in the data. When they looked only at adherent women, or those who took 80 percent of their pills, the supplements reduced hip fractures by 29 percent. [emphasis ours]... In a separate subgroup analysis of women over 60, the investigators saw a 21-percent reduction in hip fractures in the group taking the supplements.” Dr. Elizabeth Nabel, the study’s director, went on to say, “Based on all the results, women—particularly those over 60—should consider taking calcium and vitamin D for bone health.”
This viewpoint was also reflected in recent studies reported in the Journal of the American Medical Association, which determined that if taken regularly, 1,000 to 1,200 milligrams of calcium combined with 400 to 800 IU of vitamin D is effective in the prevention and treatment of osteoporosis.
When you think about your bones, you probably envision something hard and permanent, but in reality, they are living organs that are constantly changing. You build your bones until you are about 30, then your body stops adding new bone, according to the 2004 Surgeon General’s Report on Bone Health and Osteoporosis. But after your bones are fully constructed, your body still deposits and withdraws calcium from them every day.
When there is enough calcium in the blood, the body stores the extra in the bones, increasing their strength. If calcium levels in the blood are low, the body steals it from the bones to use it elsewhere, such as for your muscles and nerves. Calcium in the diet is essential, but, to get the recommended daily intake, most women need to take supplements. The best calcium supplement is the one that is taken consistently, as studies have not found a significant difference among the various types of calcium.
Vitamin D works with calcium like a key unlocking a door, allowing calcium to leave the digestive system and enter the bloodstream. It also works in the kidneys to prevent the calcium from being excreted. Vitamin D is made in the skin when it is exposed to sunlight, but this can be affected by sunscreen, and even skin color. Fish, eggs, and fortified milk are sources of vitamin D, but it is also included in most calcium supplements.
Exercise is also essential to the prevention and treatment of osteoporosis. Weight-bearing exercises, such as jogging, walking, stair climbing, dancing and weight lifting increase the overall bone mass, and improve bone strength. One hour of these exercises three times a week builds stronger bones in as early as six to nine months for most people.
Most health insurance companies provide coverage for routine testing of women over the age of 65, or earlier if they have any of the risk factors for osteoporosis. You should also get your bone density checked if you have any kind of fracture after the age of 50, according to the Surgeon General’s report.
Doctors measure bone mass via a bone mineral density (BMD) test. This easy, painless test is similar to an X-ray, and can be done in minutes. Most studies in the medical literature refer to bone testing done of the hip and spine, as these are the two most common areas of fracture.
Are You at Risk?
Age: After the age of 50, women are three times more likely than men to have a spine or hip fracture. That’s because estrogen protects the bones from weakening; the loss of bone strength correlates with declining estrogen levels in the body.
Race: Caucasian and Asian women have the highest rates of osteoporosis, although it is present in other ethnic groups, as well.
Medical record: Medical conditions, such as hypothyroidism, and some medications, including anti-seizure drugs, steroids and chemotherapy, can increase the risk of early bone loss and are good reasons to have tests done to measure bone strength.
Other risk factors include: smoking, an excessive use of alcohol, a lack of calcium in the diet and not enough exercise.
The BMD compares bone in two categories. The Z-score compares your bones to the average of other women your age and size. The T-score compares your bones to young normal values, when bones are at their peak density, usually around the age of 30. The score determines whether an individual has osteoporosis, or the beginning of thinning of the bones, called osteopenia.
A normal score of “0” indicates healthy, strong bones, while a score of –1.0 to –1.9 shows an early thinning of the bones, and correlates with a 20-percent loss of bone mass. Treatment is usually started when the score is less than –2.0, with the greatest risk of fracture at a level of –2.5 or lower. It is possible to reverse bone loss and strengthen bones with a combination of diet, exercise and medications. Bone-density measurements are taken every two to three years to monitor progress.
AS YOU AGE
You’re never too old or too young to start improving your bones. Parents can get children on the right path by encouraging at least 60 minutes of physical activity per day, and by offering high-calcium foods, such as cheese, yogurt, milk, fortified oatmeal and ice cream.
Teenagers need an hour of vigorous exercise and four servings of calcium-rich food daily, according to the Surgeon General’s report.
Adult women should keep an eye on their calcium intake (a recommended 1,000 to 1,200 milligrams), and do 30 minutes a day of physical activity, plus strength training two to three times weekly.
Seniors need to exercise, with an emphasis on building balance and strength, and up their vitamin D intake to 400IU daily (600 IU past age 70). Seniors should also make their home environments safer by removing small rugs, adding lights and handrails to staircases and using nonslip mats in the bathroom.
Sometimes, diet and exercise aren’t enough to slow bone loss, and doctors turn to osteoporosis medications. The most common variety are bisphosphonates, such as Alendronate (Fosamax), Risedronate (Actonel) and Ibandronate (Boniva). All bone goes through a cycle of breaking down and rebuilding, and bisphosphonates slow bone breakdown, and thus increase bone strength. All three are FDA-approved, available in pill form and work to prevent fractures of the hip and spine. Fosamax and Actonel are taken once a week, while Boniva is taken once a month. Recently, an intravenous form of Fosamax was approved for those who are not able to tolerate pills, and can be given every three months. Each of these medications has to be taken carefully to minimize any side effects, but all are effective.
Hormones can also be useful. Estrogen (which comes under multiple brand names, including Premarin) improves bone strength, but has some side effects. Raloxifene (Evista) was developed to provide the positive effects of estrogen on bones without the potential disadvantages. In addition to building bone in the spine, raloxifene has also been shown to decrease the risk of estrogen-dependent breast cancer by 65 percent over four years.
The newest treatment for osteoporosis is a form of parathyroid hormone named Forteo. This self-administered injection stimulates new bone formation and increases bone density. However, it has only been approved for severe cases of bone loss, and should only be used for two years. Research is underway to determine if Fortero can be safely used for a longer period of time.
Even people who appear healthy and vital can be suffering from bone loss or risking their bone health, so it’s important to know your risk factors, exercise, get enough calcium and vitamin D. After all, you need your bones to last your whole life.
Dr. Kathleen Kozak, M.D., MBA, is an internist at Straub Clinic and Hospital in downtown Honolulu.