Readers: Bone Up on Osteoporosis
Over the years, the most common questions I've had from my female patients concern aging and osteoporosis. Since it's National Osteoporosis Prevention Month, I thought I would share some of these questions along with their answers. For more general information about osteoporosis, or on new treatments available, see the Related Links section at the end of this column.
I'm a pre-menopausal woman in my 30s. Do I need to worry about osteoporosis? What can I do to prevent it?
Yes, you do need to worry about it. Over 20 million women in the United States have osteoporosis, and many more are at risk. The disease is typically asymptomatic until fractures occur -- commonly in the vertebral column -- from compression of brittle bones.
Osteoporosis is not an "old lady" disease. It can be caused by a drop in estrogen, which is key to the production of new bone, so it often begins at the onset of menopause -- in your 40s or 50s. For women with estrogen deficiency related to surgical removal of the ovaries or to anorexia nervosa (which often mimics menopause), however, osteoporosis can occur even earlier.
There are several dietary and lifestyle changes you can make to help prevent osteoporosis. Here are a few:
Meet the daily requirements for calcium and vitamin D. Make sure you're consuming plenty of calcium -- 1,000-1,200 mg per day, either through supplements or through your diet. Don't forget about vitamin D, which is necessary for the body to absorb calcium. All milk is fortified with vitamin D for this reason. Sun exposure is also a source of vitamin D (due to a chemical reaction in the skin), so be sure to go out in the sun for at least 5-10 minutes every day.
Exercise daily. Weight-bearing exercises and activities that put light stress on your bones stimulate bone strength and health. Weight lifting, vigorous walking or hiking, and aerobics are good examples.
Avoid alcohol, and don't smoke. Excessive use of alcohol has been shown to hasten the onset of osteoporosis, as has cigarette smoking.
Unfortunately, even following all these guidelines doesn't guarantee protection from osteoporosis. At the onset of menopause, you should have a bone mineral densitometry (BMD) test to determine your bone density. This painless procedure (which Medicare now pays for) will help your doctor determine if medication is necessary.
Is osteoporosis hereditary?
It does tend to run in families. There are several risk factors in addition to genetics. Osteoporosis most commonly occurs in the following types of people:
Those with a family history
Post-menopausal women
Caucasians and Asians
People over 65 years old
Women with petite body frames
People with chronic use of steroid medication (commonly taken for asthma and rheumatoid arthritis)
Women with anorexia nervosa
Certain lifestyle habits, such as excessive alcohol use and cigarette smoking, calcium-poor diet, reduced physical activity
I'm lactose intolerant, and I'm worried I'm not getting enough calcium in my diet. What are some nondairy sources?
Dairy foods provide 75 percent of all the calcium in the typical American diet, but other foods and calcium supplements can make up the difference. You can also help maintain calcium levels in your body by avoiding certain products, such as caffeinated beverages, which can interfere with calcium absorption.
The American Dietetic Association lists the following nondairy calcium-rich foods, along with the amount of calcium per average serving:
Fish sources
Canned salmon with edible bone: 205 mg
Sardines: 90 mg
Anchovies: 45 mg
Tuna: 10 mg
Soy products
Tempeh: 75 mg
Tofu: 130 mg
Calcium-fortified soy milk: 250-300 mg
Grains
Tortillas made from lime-processed corn: 40 mg
Legumes
Fruits/juices
Orange: 50 mg
Calcium-fortified orange juice: 225 mg
Dried figs: 80 mg
Greens/vegetables
Kale: 45 mg
Lettuce greens: 10 mg
Turnip greens: 100 mg
Okra: 50 mg
Rutabaga: 45 mg
Broccoli: 45 mg
Other calcium sources
Black strap molasses: 170 mg per tablespoon
Is osteoporosis reversible?
In a way, yes. Osteoporotic bone can be strengthened with medications and certain lifestyle changes. The primary therapy for women to prevent and treat osteoporosis is hormone replacement therapy (HRT), particularly estrogen replacement therapy (ERT). Estrogen helps bones rebuild and prevents them breaking down. In the normally functioning human body, there is a constant remodeling of bone, a harmonious balance between breakdown and bone formation. In estrogen-deficient women (post-menopausal), however, bone breakdown occurs at a greater rate than bone formation, thereby leading to thin and brittle bones. ERT helps even when considerable bone loss has occurred.
The fact that a third of post-menopausal women who fracture a hip die within one year is one of the many reasons to work on reversing this disease. The medicines available now stimulate the building up of bone and can strengthen bone weakened by osteoporosis.
HRT, specifically ERT, has a positive effect on bone density after menopause. HRT is available as an oral medication or as a transdermal patch. The most effective treatment for many women could be ERT plus alendronate.
Alendronate (brand name Fosamax) prevents the breakdown of bone, increases bone density, and reduces the incidence of fractures. Alendronate is taken in pill form.
Calcitonin (brand name Miacalcin) is intended for use by women who have been post-menopausal for at least five years. It directly inhibits the breakdown of bone. Calcitonin is available in the form of a nasal spray and as an injectable solution.
Raloxifene (brand name Evista) is a new drug that has not been approved by the FDA yet, but in trials has been shown to be effective in preventing osteoporotic fractures.
Related links:
Rx.magazine feature story: The Bones Have It: Brand new drugs fight osteoporosis in women and men, Osteoporosis in Men
Information from The National Osteoporosis Foundation
