Protect Your Bones

Weakened bones and stooped posture don't have to be a part of aging. Osteoporosis can be prevented. And for those who already have this disease, there are treatments.

Eleanor Mayfield, ELS

We've all seen her on the street or in the supermarket: A frail, elderly woman with a stooped upper back. She used to be several inches taller than she is now. It's just something that happens as we get older, we think.

Actually, stooped posture isn't an inevitable part of aging. Although she may not know it, that woman has osteoporosis--a disease of weak bones. Her stooped posture is caused by small fractures in her spinal bones, which have become thin and fragile. Over time, these small spinal fractures caused a decrease in height and a rounding of her shoulders. She's at high risk for falling and breaking a hip, if she hasn't done so already (see "Bone Fracture Areas").

According to the National Osteoporosis Foundation (NOF), 10 million Americans--eight million of them women--have osteoporosis. Another 18 million--including more than 14 million women--are at risk for the disease because they have low bone mass (thinner-than-normal bones). Osteoporosis causes more than 1.5 million fractures every year, including 300,000 broken hips and 700,000 broken spinal bones (vertebrae). In the elderly, a broken hip can mean disability or even death.

Bone: A Living Tissue

"The skeleton is a living, dynamic organ just like the heart," says Felicia Cosman, MD, osteoporosis specialist at Helen Hayes Hospital in West Haverstraw, NY, and NOF Clinical Director. "The skeleton has cells that need to keep healthy. These include cells that make bone and cells that dissolve bone. Bone is constantly renewing itself. About every five years, every piece of bone in the human body is rejuvenated."

Most bone mass develops during childhood and the teenage years, but bones continue to grow in density (thickness) even after they stop growing in size. Most people reach their peak bone density between the ages of 18 and 25. After that, bone begins to break down faster than new bone is formed.

For women, bone loss speeds up after menopause--when the ovaries stop making estrogen, which protects against bone loss. Women can lose up to a fifth of their bone mass in the five to seven years after menopause, increasing their risk for osteoporosis. Although men don't go through this same life change, they too are at increased risk of osteoporosis as they age (see "Osteoporosis in Men").

"It's natural to lose a certain amount of bone as we get older," says Dr. Cosman. "But it's not natural to get osteoporosis." Osteoporosis can affect younger people, too, she says. Young women with the eating disorder anorexia nervosa and people who take certain kinds of medications that interfere with calcium absorption are at higher risk.

No Symptoms

Because osteoporosis develops without symptoms, many people have the disease without knowing it--until they fall and break a bone. The NOF estimates that one in two women, and one in eight men, over age 50 will have a fracture caused by osteoporosis during their lifetime. Hip fractures can leave one permanently disabled and in need of long-term care or help from others to do routine chores. Wrist fractures can also be disabling, making even simple tasks such as getting dressed difficult or impossible to manage alone (see "Preventing Falls").

Who's at Risk?

In addition to advanced age, you're at higher risk for osteoporosis if you:

• are female
• are Caucasian or Asian (although women of all races can get osteoporosis)
• are thin or have a small frame
• eat a low-calcium diet
• experienced menopause before age 45 (naturally or because of surgical removal of ovaries)
• have a family history of the disease
• have an inactive lifestyle
• have low estrogen levels
• smoke
• take certain medications that can interfere with calcium absorption when taken for a long time or at high doses.

The good news, however, is that osteoporosis can be prevented. Diet and lifestyle changes can prevent bone loss. A painless test can detect bone loss early, and medications are now available that stop further bone loss.

A Preventable Disease

Most people get osteoporosis when they're older, but the disease actually begins developing many years earlier. The National Institute of Child Health and Human Development, part of the National Institutes of Health, calls osteoporosis a pediatric preventable disease. "Osteoporosis prevention starts in childhood," says Robert B. Taylor, MD, Professor of Family Medicine at Oregon Health Sciences University in Portland. "Exercise and a calcium-rich diet in childhood build strong bones that will help to prevent osteoporosis when you're 65."

Health experts recommend four steps for preventing osteoporosis:

• Eat a balanced diet that is rich in calcium and vitamin D.
• Do regular weight-bearing exercises.
• Live a healthy lifestyle--limit use of alcohol and don't smoke.
• Have a bone density test and take medication when appropriate.

A Balanced Diet

Calcium is a mineral that strengthens bones. Almost all of the body's calcium is in the bones and teeth. A small amount is in the blood, where it is needed for life-sustaining functions such as making blood clot and regulating the heartbeat. If a person isn't consuming enough calcium, the body takes it from the bones to maintain blood levels. Over time, this calcium loss weakens the bones.

Surveys show that many Americans don't consume enough calcium. According to the NOF, many women and girls consume less than half the amount of calcium recommended to grow and maintain healthy bones (see "Calcium: Get the Facts").

Daily Requirement

210 mg

270 mg

500 mg

800 mg

1,300 mg

1,300 mg

1,000 mg

1,200 mg

1,300 mg

1,000 mg

The richest sources of dietary calcium are dairy products. For example, 1 cup of low-fat or skim milk or low-fat yogurt provides 300 mg of calcium. Other good sources of calcium include dark green leafy vegetables, grains, beans, peas, lentils, and soy foods such as tofu. Many breakfast foods and some brands of orange juice are fortified with calcium.

Getting enough calcium from dietary sources isn't quite as simple as eating enough calcium-rich foods, although that's crucial. Other factors affect how well your body absorbs the calcium you consume. For instance, to absorb calcium from food, the body needs vitamin D. Your body makes vitamin D from sunlight and, to a lesser extent, from food. Wearing sunscreen, however, blocks absorption of vitamin D from the sun. Milk is usually fortified with vitamin D, as are some breakfast cereals. Eggs, margarine, and fatty fish are other dietary sources of vitamin D. You can also get vitamin D from a multivitamin supplement.

If your diet is high in protein, your body loses more calcium in urine. Most Americans eat too much protein and too little calcium. Keep portion sizes of meat, poultry, and fish to five or six ounces a day. Eating a lot of sodium and drinking a lot of caffeine also increase calcium loss in urine--so take it easy with the salt shaker and forgo that third cup of coffee.

If you are lactose intolerant and have trouble digesting dairy foods, especially milk, you may find cheese or yogurt easier to digest. Drinking milk in small portions (less than a cup) may also reduce discomfort. Milk that's specially treated for people who are lactose intolerant is readily available at most supermarket dairy counters.

If you don't get enough calcium from dietary sources, consider taking a calcium supplement. Ask your doctor about which type of calcium supplement is best for you.

Weight-bearing Exercise

"Use it or lose it" applies to bones as well as to muscles. Both get stronger the more you use them. Weight-bearing exercise is any exercise in which your feet and legs bear your weight. Walking, jogging, stair climbing, and dancing are all forms of weight-bearing exercise.

Bicycling and swimming are not weight-bearing activities, but they are still good exercise because they work the heart, lungs, and muscles, says Dr. Cosman. "Having more muscle seems to protect against fractures," she says. "You're less likely to fall and, if you do fall, you're less likely to break a bone."

If you haven't exercised regularly before, find an activity that you enjoy, start slowly, and make it a habit. "Start with five minutes on the treadmill and build up from there," says Dr. Cosman. "Any activity is good and the opposite is bad--people who are very sedentary or immobile have a much higher risk of osteoporosis." Dr. Taylor adds, "The only time exercise is bad is when young women engage in extreme exercise to the point of not having periods. Then they have low estrogen and calcium loss. With that exception, exercise at all ages is good."

A Healthy Lifestyle

Here's another reason to quit smoking (or not start) and to limit alcohol use: It's bad for your bones. Women who smoke have lower levels of estrogen than nonsmokers. Smokers also may absorb less calcium from their diets. Regularly drinking 2 to 3 ounces of alcohol a day may be damaging to the skeleton. People who drink heavily are more prone to bone loss and fractures for two reasons: they tend to eat poorly and they are at higher risk of falling.

Tests to Detect Osteoporosis

A bone density test is a kind of x-ray that can detect low bone mass before a fracture occurs. The NOF recommends bone density testing for:

• all women age 65 and older
• postmenopausal women under age 65 who have one or more risk factors for osteoporosis
• postmenopausal women who break a bone
• women who have been on hormone replacement therapy for several years
• women who are considering treatment for osteoporosis.

Bone density testing is painless and safe. It can be done several different ways. Central testing measures bone density in the hip and spine. Peripheral testing measures it in the finger, wrist, kneecap, shin, or heel. According to Dr. Cosman, a central bone density test is the best. "X-rays of the hip and spine are the best predictors of hip and spinal fractures, and those are the fractures that cause the most disability and death."

Treatment

Osteoporosis cannot be cured, but there are medications that can reduce bone loss, increase bone density, and reduce the risk of spinal and hip fractures. If a bone density test shows that you have low bone mass or if you are at high risk for osteoporosis because of a family history or for other reasons, your doctor may recommend medication.

Four medications have been approved by the US Food and Drug Administration to prevent or treat osteoporosis:

Estrogen replacement therapy (ERT) controls menopausal symptoms also reduces the risk of osteoporosis and possibly heart disease, says Dr. Cosman. "But there is a worry about whether long-term ERT increases the risk of breast cancer--we still don't know." ERT can be taken as a pill or worn as a skin patch. Side effects may include nausea, bloating, breast tenderness, and high blood pressure. In addition, ERT may increase the risk of blood clotting problems. It is almost always prescribed in combination with another hormone, progestin, to reduce the risk of endometrial cancer in women who have not undergone hysterectomy (who have not had their uterus surgically removed).

Fosamax® (alendronate) is approved for the treatment and prevention of osteoporosis in postmenopausal women. A possible side effect is heartburn or difficulty swallowing. To reduce this risk, women taking alendronate must follow specific directions for taking the medication correctly.

Evista® (raloxifene) is approved to prevent osteoporosis in postmenopausal women. This relatively new drug is a chemical cousin of tamoxifen, which is used to treat and prevent breast cancer. Side effects are not common but may include hot flashes and clotting problems.

Calcitonin slows bone loss and increases spinal bone density modestly in postmenopausal women. Taken as either an injection or a nasal spray (Miacalcin®), calcitonin is an alternative for women who cannot or choose not to take hormones. "Its effects are less potent than those of other drugs for osteoporosis," says Dr. Cosman. "But many doctors prescribe it because it has very few side effects."

The choice of which medication is used to treat osteoporosis depends on a woman's age and her individual health history. Ask your doctor which drug is appropriate for you.

So stand up to osteoporosis! It's a preventable, and treatable, disease.

References:

Eleanor Mayfield, ELS, is a writer and editor in Silver Spring, MD.

Originally published in The Female Patient Waiting Room Edition -- October, 1999

© Copyright, 1999 Quadrant Publishing, All Rights Reserved

Reprints are not allowed without the expressed written consent of Quadrant Publishing.