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[HEALTHTRACK]

Simple Steps to Better Bones

HEALTHTRACK - JUL/AUG 97
A SUPPLEMENT TO THE PHYSICIAN AND SPORTSMEDICINE FOR THE WAITING ROOM


When you think about it, our bones have a pretty thankless job. They carry us everywhere, give us tireless support, and supply our blood with important nutrients. In return, we tend to ignore them.

That's a bad idea. If we don't pay attention to building and maintaining strong bones, they can become thin and weak over time. This process of bone loss, called osteoporosis, makes bones much more likely to break. Bone loss is a serious problem for many older people, especially women. But to a great extent, such loss is preventable. In fact, the more actively you resist osteoporosis, the better off you—and your bones—will be.

What Is Osteoporosis?

Osteoporosis is a condition caused by estrogen loss, which causes bones to lose minerals—mainly calcium. Bones become so brittle that even a minor injury can break a wrist, hip, or spine. Although it does affect men, osteoporosis is much more likely to affect women.

Postmenopausal women (especially Caucasian women) are at increased risk of osteoporosis, as are people who smoke, use alcohol, lead an inactive lifestyle, avoid calcium-rich foods, or have blood relatives who have osteoporosis. Some medications and certain chronic diseases can also aggravate bone loss.

Don't Sit Still for Bone Loss

Exercise plays an extremely important role in preventing bone loss. Like muscles, bones stay stronger with regular exercise. The best exercises to strengthen bones are weight-bearing exercises—those that you do while on your feet—such as walking, running, and playing tennis. Weight lifting and other forms of strength training are also good.

Try to do some form of weight-bearing exercise several times a week (ideally for 20 to 60 minutes 3 to 5 times a week). Be sure to start out slowly and increase the amount and intensity of exercise gradually.

The Role of Estrogen

The female hormone estrogen is another important player in preventing osteoporosis. When women's estrogen levels drop after menopause, calcium is lost from their bones, most rapidly during the first 6 years, which is why many women develop osteoporosis in their 60s or 70s.

Estrogen levels may also decrease in younger women who exercise too intensely or have disordered eating patterns. When this happens, bone loss can occur very quickly in these women—as much as 2% to 6% of total bone mass per year can be irreversibly leached away. Eventually, a full quarter of bone mass may be lost.

Estrogen therapy restores estrogen levels. The therapy can't entirely repair weakened bones, but it does prevent further bone loss. Talk to your doctor if you have questions about estrogen therapy.

Calcium Builds Bones

Your body uses calcium to form bones and teeth, and lack of calcium is a risk factor for osteoporosis. Calcium also helps nerves and muscles work properly and helps blood clot. Your bones serve as "banks" where calcium can be deposited and withdrawn into your blood for ready use.

How much calcium is enough? The National Institutes of Health recommends the following daily intake of calcium: children 10 and under, 800 mg; adolescents and young adults (ages 11 to 24), 1,200 mg to 1,500 mg; men age 25 and older, 1,000 mg; women age 25 to 50, 1,000 mg; women who have stopped menstruating, 1,000 mg to 1,500 mg; women age 65 and older, 1,500 mg. These recommendations are slightly higher than the recommended dietary allowance (RDA).

Calcium-Rich Bone Bilders
Milk Pinto beans

Yogurt Spinach

Almonds Orange juice (calcium enriched)

Broccoli Tofu (calcium processed)

Kale Salmon (canned with bones)

Soy milk Sardines (canned with bones)

Milk and other dairy foods are the easiest and most popular food sources of calcium. One dairy serving (8 ounces of milk or yogurt, 1 ounce of cheese) contains about 300 mg of calcium. Most dairy products have lowfat counterparts that are higher in calcium. If you are lactose intolerant (meaning you have trouble digesting lactose, the sugar found in dairy products), you might want to try low-lactose or lactose-free dairy products or try taking products that help you digest lactose. See the table at right for foods rich in calcium.

Some foods interfere with the absorption of calcium or cause calcium loss: alcohol, caffeine, carbonated beverages, fiber supplements, a diet high in salt, and zinc supplements. Also, avoid taking a calcium supplement alongside high-fiber breakfast foods.

A Matter of Timing

No matter what your age, you can take steps to prevent bone loss. Think of osteoporosis prevention as a three-legged stool: exercise, estrogen, and calcium. Without one of the legs, the osteoporosis prevention stool doesn't stand. If you are:

Between 10 and 20 years old: Start making deposits in your "calcium banks." To make your bones as strong as possible, you need 1,200 mg to 1,500 mg of calcium each day. Choose milk (at least three glasses a day) instead of soft drinks.

Regular periods are important in preventing osteoporosis. Talk to your doctor if you think you might have an eating disorder or if your periods are irregular or haven't started by the time you are 16.

Between 20 and 35: Your bones will reach their peak strength during these years, so continue to get plenty of calcium and exercise, and report any changes in your period to your doctor. Be sure to increase your calcium intake if you're pregnant or nursing.

Between 35 and 50: You may begin losing bone during this time, so getting enough calcium and exercise is very important. Most women enter menopause between ages 42 and 55. Talk with your doctor about estrogen treatment if your periods become irregular or you develop other signs of menopause, such as hot flashes.

Over 50: If you have gone through menopause, you may be losing bone mass at a rate of 1% to 6% per year as estrogen production slows. For most women, estrogen replacement therapy is a very important step toward preventing osteoporosis. Ask your doctor if it or another medication option is appropriate for you.

Remember that getting adequate calcium and exercise are still important. You should be getting about 1,500 mg of calcium each day. You may also need extra vitamin D to help your body absorb calcium. And take the time to walk, jog, play tennis, or strength train for at least 20 minutes three times a week.


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