Osteoporosis

Walking Tall into Your Golden Years

Imagine a bank that never let you know how much (or how little) money you have in your account. Unless you were a diligent bookkeeper, chances are that sooner or later, you'd start bouncing checks. Well, your bones are that bank, only instead of money, you're withdrawing calcium.

Essentially, that's what happens when people get osteoporosis, a disease causing porous bones: Their skeletons become bankrupt. Their bodies have withdrawn more calcium from the bones than has been deposited over the years, and all that's left is a fragile shell.

Osteoporosis is responsible for 1.5 million fractures each year, most notably fractures of the vertebrae (these cause the hunched appearance often seen in elderly women), forearms, wrists and hips (these are often crippling and sometimes fatal).

That's the bad news. The good news is that osteoporosis is both preventable and treatable.

"There is no reason this disease should exist. It's so preventable just through nutrition and exercise, if a woman starts young enough," says Ruth S. Jacobowitz, former vice-president of Mount Sinai Medical Center in Cleveland, a member of the board of trustees of the National Council on Women's Health and author of 150 Most-Asked Questions about Osteoporosis. "It is never too early and never too late to build bone. Even very elderly women can still build some amount of bone density."

Making Deposits into the Bone Bank

The first step in building bone is understanding how bones work. Even after we've stopped growing, our bones undergo constant remodeling. Remodeling is the actual term that doctors use to describe the body's ongoing process of removing old bone and forming new bone. Generally, the formation of new bone stays ahead of, or even with, the removal of old bone during the first 20 to 30 years of our lives.

Sometime after age 30, our bones begin operating in the red, and both men and women lose slightly more bone than they form--that is, until women hit menopause and stop producing estrogen, one of the hormones that regulate remodeling. Then they lose significantly more bone than men, up to 2 to 5 percent a year during the first five to seven years after menopause. For this reason, osteoporosis is much more common among women, though it does occur in elderly men.

That is why it's particularly important for women to build and maintain peak bone mass, the maximum amount of bone you can form during your lifetime. And you form peak bone mass by taking in calcium and getting plenty of exercise, explains Clifford Rosen, M.D., director of the Maine Center for Osteoporosis Research and Education at St. Joseph's Hospital in Bangor. The earlier you start, the better, because the majority of peak bone mass is achieved by your midtwenties, though some researchers believe you can build bone until age 35.

Does that mean you're doomed if you're already past age 30 and just learning what peak bone mass is? "Absolutely not," says Dr. Rosen. Calcium and exercise can prevent the bone loss that occurs in your thirties and forties. "And slowing bone loss is enough to keep you from having osteoporosis, no matter how low your peak bone mass," he says.

One of the most effective ways of preventing bone loss and osteoporotic fractures is hormone replacement therapy, says David Dempster, Ph.D., director of the Regional Bone Center at Helen Hayes Hospital in West Haberstraw, New York, and associate professor of clinical pathology at Columbia University in New York City. Hormone replacement therapy is not appropriate for all women, however. You should discuss the pros and cons of this treatment with your doctor.

And medical experts agree that for both women and men, a healthy diet plays an important role in preventing and treating osteoporosis.

In addition to calcium, the nutrients shown by research to have the best bone-building potential include vitamin D, boron, magnesium, fluoride, manganese, copper, zincand vitamin K. Here's what we know so far.

Straight from the Cow

Mom always said "Drink your milk, or you won't have strong teeth and bones." As usual, she was right.

"Far and away, the biggest problem with osteoporosis is a lack of calcium in people's diets," explains Paul Saltman, Ph.D., professor of biology at the University of California, San Diego.

Calcium, a mineral abundant in milk, is essential for strong, healthy bones. In fact, 99 percent of the body's calciumis stored in the skeleton. But you also need a stable level of serum calcium(calcium in your blood) for normal heartbeat, nerve and muscle function and blood coagulation. It's your bones that suffer when there isn't enough to go around.

Maintaining enough calcium in the blood is the body's ultimate priority, explains Dr. Rosen. "If it doesn't have enough, it goes to the reservoir and takes it," he says. The reservoir, in this case, is your bones.

To keep that reservoir full and calcium-rich, Dr. Saltman recommends that all people, beginning in their teens, take supplements and eat a good diet to ensure that they receive between 1,200 and 1,500 milligrams of calcium daily.

According to researchers at the University of California, San Diego, every little bit of calcium counts. Of the 581 60- to 79-year-old women they studied, those who had drunk one or more glasses of milk daily as adolescents and young adults had significantly higher bone mineral density at the mid-forearm (3 to 4 percent), spine (5 percent) and hip than those who had not. The effect of drinking milk on bone mineral density was even greater at the hip (4 percent) and spine (7 percent) for adults ages 20 to 50.

Calciumcan also be helpful in treating osteoporosis once the disease has developed. Investigators at Winthrop-University Hospital in Mineola, New York, studied 118 women past the age of menopause. Over a three-year period, they gave the women 1,700 milligrams of calcium, 1,700 milligrams of calciumplus the female hormones estrogen and progesterone or placebos (medically ineffective pills). Though the calcium-hormone mix was most effective, calciumalone significantly slowed bone mineral loss. Researchers measured bone mineral loss in the upper thighbone, noting a 0.8 percent decline a year in the women taking calcium versus a 2 percent decline a year in those taking the placebos.

When it comes to getting enough calcium, however, drinking more milk is by no means the final word. Calcium from dairy products can be difficult to absorb, and many people have difficulty digesting dairy products, says Neal Barnard, M.D., president of the Physicians Committee for Responsible Medicine in Washington, D.C., and author of Eat Right, Live Longer. He recommends foods such as beans, broccoli and fortified orange juice as calciumsources instead. Other calcium-rich foods include collard greens, kale, mustard greens, butternut squash, tofu and sweet potatoes.

The Daily Value for calcium is 1,000 milligrams. And the National Institutes of Health in Bethesda, Maryland, recommends the following intakes:

* Men, ages 25 to 65: 1,000 milligrams

* Women, ages 25 to 50: 1,000 milligrams

* Pregnant and nursing women: 1,200 to 1,500 milligrams

* Women at menopause (ages 51 to 65) who are taking estrogen: 1,000 milligrams

* Women at menopause (ages 51 to 65) who are not taking estrogen: 1,500
milligrams

* Men and women over age 65: 1,500 milligrams

Since many people fall short of getting these amounts from foods, doctors often recommend supplements of between 500 and 1,200 milligrams of calcium per day to make up the difference.

Play in the Sunshine for Vitamin D

Often referred to as the sunshine vitamin, vitamin Dis a must if you want all of that calciumto do any good. Vitamin D, which your skin makes whenever it's exposed to sunlight (except during the winter at northern latitudes), helps your body absorb calcium and build good bones.

There are no conclusive studies pointing to vitamin Ddeficiency as a direct cause of osteoporosis. It is well-documented that vitamin D deficiency causes osteomalacia, or soft bones, in adults, which could contribute to fractures.

Vitamin Dmight also be useful as an osteoporosis treatment. In one study, Finnish researchers found that 341 elderly people (mostly women ages 75 and older), given annual large-dose injections of vitamin D during a five-year period, experienced fewer fractures than 458 people who did not receive the vitamin.

"Research here in Boston and in Europe has found that up to 40 percent of elderly men and women with hip fractures are vitamin D-deficient," says Michael F. Holick, M.D., Ph.D., director of the General Clinical Research Center and chief of the Section of Endocrinology, Diabetes and Metabolism, both at Boston University Medical Center.

Unfortunately, your skin's ability to manufacture vitamin Ddecreases with age, says Dr. Holick. Matters are even worse for those living where the days are short and the winters are long. You can't make any vitamin Din the wintertime at northern latitudes such as Boston. "During the months from November through February in Boston, even if you exposed your entire body to sunlight from sunrise to sunset, you would not be able to make enough vitamin D to satisfy your body's requirement," Dr. Holick says. And the closer your abode to the polar ice caps, the longer that stretch.

"This problem is compounded by the use of sunscreen in the summer," adds Dr. Holick. "Sunscreen with an SPF (sun protection factor) of eight is enough to markedly diminish your ability to make vitamin D. Clothing completely prevents it."

Although it's okay to drink fortified milk, you shouldn't count on it as your primary source of vitamin D, notes Dr. Holick. "It is difficult to fortify milk with vitamin D, and our research has shown that only 30 percent of milk samples contain the amount of vitamin D shown on the label. That percentage is even lower in skim milk samples."

That makes it rather difficult to get adequate amounts of vitamin Dfrom your diet alone. Fortunately, the answer to the vitamin D dilemma is as close as your local drugstore, especially if you walk there on a sunny day.

Vitamin Dcan be toxic in large doses. For that reason, you should never take supplements in excess of 600 international units daily unless your doctor specifically recommends it. Many multivitamin/mineral formulas contain adequate amounts of vitamin D, however. "Taking a multivitamin/mineral supplement that contains 400 international units of vitamin Dessentially guarantees that you get at least the adult Daily Value of vitamin D, which is also 400 international units," says Dr. Holick. "We also recommend that people, particularly the elderly, go outside for five to ten minutes, two or three times a week, during the spring, summer and fall for sun exposure on their hands, faces and arms. It is casual exposure to sunlight that provides us with more vitamin D."

Take Magnesiumto Regulate Calcium

Magnesium, an essential mineral used to treat almost everything from depression to heart attack, is also crucial to bone health. Magnesiumhelps calciumget into the bones and also converts vitamin Dto its active form in the body. Nearly half of the body's magnesium is found in the skeleton.

"We don't have enough research, but if I had to guess which nutrient is most important to bone health, I would say magnesium," says Alan R. Gaby, M.D., a doctor in Seattle specializing in natural and nutritional medicine, past president of the American Holistic Medical Association and author of Preventing and Reversing Osteoporosis.

Magnesiummay also help in the treatment of osteoporosis. Researchers in Israel studied 31 women with osteoporosis who were past the age of menopause. They gave the women daily magnesiumsupplements of 250 to 750 milligrams for 6 months and then 250 milligrams for 18 months. At the end of that period, 22 women increased their bone density by 1 to 8 percent, and 5 women experienced decreases in their rates of bone loss. Conversely, bone density decreased markedly in 23 women who did not receive magnesium supplements during the same period.

Here in the United States, the U.S. Department of Agriculture continues to study magnesium's role in osteoporosis, says Forrest H. Nielsen, Ph.D., center director for the U.S. Department of Agriculture Grand Forks Human Nutrition Research Center in North Dakota. "Based on what we know about magnesiumregulating calcium, we can say that an adequate magnesium diet is necessary to maintain healthy bones," he says.

The Daily Value for magnesiumis 400 milligrams. Since many Americans lack sufficient magnesiumin their diets, doctors who recommend magnesiumsupplements advise taking 200 to 400 milligrams daily. (If you have heart or kidney problems, you should talk to your doctor before taking magnesiumsupplements.) Magnesium-rich foods include wheat germ, sunflower seeds, seafood, nuts, dairy products and green, leafy vegetables.

Boron Plugs the Calcium Leak

Researchers have speculated that boron, a trace mineral found mostly in fruits and vegetables, may reduce urinary excretion of both calciumand magnesium and therefore help prevent osteoporosis.

"It's still too early to tell how much of a benefit boronis," says Curtiss Hunt, Ph.D., a research biologist at the Grand Forks Human Nutrition Research Center. In one study, Dr. Hunt and his fellow researchers found marginal differences in the amounts of calciumand magnesiumexcreted in the urine of 12 women past the age of menopause who were given first a low-borondiet and then daily supplements of three milligrams of boron.

"So far, we've found that boronhas a slight effect in decreasing urinary excretion of calciumand magnesiumas well as in increasing the production of estrogen and testosterone, but the results haven't been dramatic," says Dr. Hunt. "It's still important to eat a boron-rich diet, however. Beyond a shadow of a doubt, boronaffects bone and mineral metabolism, especially in animals. But it would be foolhardy to take boronsupplements at this time. People should eat their fruits and vegetables. You can get 0.5 milligram of boron just by eating one good-size apple."

Something in the Water Could Help

Fluoride, the electrically charged form of fluorine, has long been touted for its cavity-fighting ability. Now some researchers believe it can build bones as well.

"The women in our study had a 70 percent reduction in spinal fractures over a 30-month period and close to a 5 percent increase in spinal bone density every year for almost three years," says Khashayar Sakhaee, M.D., professor of internal medicine at the Center for Mineral Metabolism and Clinical Research of the University of Texas Southwestern Medical Center at Dallas.

In the study, Dr. Sakhaee gave 48 women who were past menopause 25 milligrams of slow-release fluoride and 800 milligrams of calcium(as calcium citrate) twice a day for three 12-month cycles, with a 2-month break from fluoride between cycles. With this new method of delivery, Dr. Sakhaee says, fluoride treatment is safe and effective.

"Other researchers used to use a rapid-release fluoride that went right to the skeleton, and the patients were getting toxic levels," says Dr. Sakhaee. The rapid-release formula did create dense bones, he explains, but the bone material it formed was brittle and weak. The new slow-release formula is creating strong bones.

Researchers remain leery about rapid-release sodium fluoride. Very high doses of fluoride, from 2,500 to 5,000 milligrams, can be fatal, though amounts needed for bone health are nowhere near that level, says Dr. Sakhaee.

"People really aren't getting enough fluoride to do their bones any good," says Dr. Sakhaee. He notes that soil and well water are rich in fluoride, but in towns and cities where the water is fluoridated, government standards prohibit more than one milligram of fluoride per liter of water. And many communities don't have fluoridated water at all.

Fluoride supplements are available only with a doctor's prescription. If you want to try fluoride, you'll have to discuss these supplements with your doctor. If your water isn't fluoridated, good food sources of fluoride include tea, mackerel and canned salmon with bones. Daily intake of up to ten milligrams of fluoride from foods and water is considered safe for adults.

Zinc, Copperand Manganese:
Working Together for Stronger Bones

For years, researchers have looked for connections between osteoporosis and the minerals zinc, copperand manganese. While it's well-documented that deficiency of any one of these nutrients has a negative impact on bone health, research shows that they may work best when taken together.

"The diets of many elderly people are lacking in essential nutrients, including zinc. And certainly, zincdeficiency leads to problems with bone metabolism," says Joseph Soares, Ph.D., professor of nutrition in the nutritional sciences program at the University of Maryland at College Park. It's not known, however, whether zinc deficiency plays a role in the development of osteoporosis, he says.

The story is the same for copper. Experiments with copperdeficiency in animals have been reported to produce bone abnormalities, and severe copperdeficiency has been reported to result in osteoporosis in malnourished premature infants, says J. Cecil Smith, Ph.D., research chemist at the U.S. Department of Agriculture Beltsville Human Nutrition Research Center in Maryland. "But there are no conclusive studies on copper and osteoporosis," he says.

Manganeseis also essential to bone formation, and manganesedeficiency has been reported in women with osteoporosis. Dr. Nielsen maintains that like zincand copper, manganese probably works best in concert with other vitamins and minerals.

Recognizing the importance of each of these minerals, investigators at the University of California, San Diego, studied the effects of zinc, copperand manganesewhen taken together. During a two-year study of 59 women past the age of menopause, the researchers found that 1,000 milligrams of calciumslowed spinal bone mineral loss. Adding a "mineral cocktail" of 15 milligrams of zinc, 2.5 milligrams of copperand 5 milligrams of manganese, however, actually stopped bone mineral loss in these women.

"For the best results, I recommend that people take a multivitamin/mineral supplement that supplies 100 percent of the daily requirements of zinc, copperand manganeseas well as a separate calcium supplement," says Dr. Saltman, a leading investigator in the study.

The Daily Value for zincis 15 milligrams; for both copperand manganese, it's 2 milligrams. Since too much zinccan block the absorption of copper, it is important to keep them in balance.

Vitamin K: The Unsung Hero

If you were to tell someone to get vitamin K, their response would probably be "Vitamin what?" Yet vitamin K, abundant in the food chain and produced by intestinal bacteria, plays a key role in bone formation. And vitamin K deficiency, which previously thought to be very rare, may be a factor in osteoporosis.

"Research shows that people with osteoporosis have low blood levels of vitamin K," says Dr. Gaby, who believes that vitamin Kdeficiency may not be all that rare. When medical scientists deemed vitamin Kdeficiency a rarity, they were using crude measuring techniques, he says. "And our overuse of antibiotics today may be inhibiting intestinal vitamin K production," he adds.

One study done in the Netherlands, in fact, showed that vitamin Kmay help protect the body's calciumstores. Seventy women past the age of menopause were given one milligram (1,000 micrograms) of vitamin Kdaily for three months. They experienced "significant" decreases in urinary calcium loss.

The Daily Value for vitamin K is 80 micrograms, and it's easy to get this vitamin in your diet. Fruits, leafy greens, root vegetables, seeds and dairy products are all good sources. For those who wish to take supplements, 100 micrograms daily is a safe limit, says Dr. Gaby, although he often prescribes larger amounts in specific cases.

The Grab Bag

In addition to these vitamins and minerals, some doctors have suggested the possible benefits of vitamin C, vitamin B₆and folic acid. Researchers don't recommend individual supplements of these nutrients for osteoporosis, but they don't hesitate to recommend a little multivitamin/mineral insurance.

"It wouldn't hurt to take your calcium supplement as well as a multivitamin/mineral to make sure that you're getting the Daily Values of all of the essential vitamins and minerals," advises Dr. Saltman.