The word osteoporosis literally means porous bones. It occurs when bones lose an excessive amount of their protein and mineral content, particularly calcium.
Over time, bone mass, and therefore bone strength, is decreased. As a result, the bones become fragile and break easily. Even a sneeze or a sudden movement may be enough to break a bone in someone with severe osteoporosis.
Osteoporosis is a serious public health problem. Some 28 million people in the United States are affected by this potentially debilitating disease, which is responsible for 1.5 million fractures (broken bones) annually.
These fractures, which are often the first sign of the disease, can affect any bone, but the most common locations are the hip, spine, and wrist.
Breaks in the hip and spine are of special concern because they almost always require hospitalization and major surgery; and may lead to other serious consequences, including permanent disability and even death.
To understand osteoporosis, it is helpful to understand the basics of bone formation. Bone is living tissue that’s constantly being renewed in a two-stage process (resorption and formation) that occurs throughout life.
In the resorption stage, old bone is broken down and removed by cells called osteoclasts. In the formation stage, cells called osteoblasts build new bone to replace the old.
During childhood and early adulthood, more bone is produced than removed, reaching its maximum mass and strength by the mid-30s. After that, bone is lost at a faster pace than it’s formed, so the amount of bone in the skeleton begins to slowly decline.
Most cases of osteoporosis occur as an acceleration of this normal aging process. That is referred to as primary osteoporosis. The condition can also be caused by other disease processes or prolonged use of certain medications that result in bone loss; if so, it is called secondary osteoporosis.
Osteoporosis occurs most often in older people, especially in women after menopause. It affects nearly half of all adults, men and women, over the age of 75. Women, however, are five times more likely than men to develop the disease.
They have smaller, thinner bones than men to begin with, and they lose bone mass more rapidly after menopause (usually around age 50), when they stop producing a bone-protecting hormone called estrogen. In the five to seven years following menopause, women can lose about 20% of their bone mass. By age 65 or 70, though, men and women lose bone mass at the same rate.
As an increasing number of men live longer, health professionals are increasingly aware that osteoporosis is an important health issue for men as well. In fact, men account for about 20% of all spinal fractures and up to 30% of all hip fractures due to osteoporosis.
Causes and symptoms
A number of factors increase the risk of developing osteoporosis. They include:
- Age. Osteoporosis is more likely as people grow older and their bones lose strength.
- Sex. Women are more likely to have osteoporosis because they start out with less bone. They also lose bone tissue more rapidly as they age. While women commonly lose 30%–50% of their bone mass over their lifetimes, men lose only 20%–33% of theirs.
- Race. Caucasian and Asian women are most at risk for the disease, but African American and Hispanic women can get it too.
- Body type. Women with small bones or thin frames are more liable to develop osteoporosis.
- Early menopause. Women who begin menopause early because of heredity, surgery, or lots of physical exercise may lose large amounts of bone tissue early in life. Such conditions as anorexia and bulimia may also lead to early menopause and osteoporosis.
- Lifestyle. People who smoke or drink too much, or do not get enough exercise, have an increased chance of getting osteoporosis.
- Medications. Certain prescription medications may speed up the loss of bone. These drugs include methotrexate, cimetidine, corticosteroids, and heparin.
- Diet. Adults who do not get enough calcium or protein may be more likely to have osteoporosis. People who constantly diet are more prone to the disease.
Osteoporosis is often called the silent disease, because bone loss occurs without symptoms. People often don’t know they have the disease until a bone breaks, frequently in a minor fall that wouldn’t normally cause a fracture.
A common occurrence is compression fractures of the spine. These can happen even after a seemingly normal activity, such as bending or twisting to pick up a light object.
The fractures can cause severe back pain, but sometimes they go unnoticed. Either way, the vertebrae collapse down on themselves, and the person actually loses height. The hunchback appearance of many elderly women, sometimes called dowager’s hump or widow’s hump, is due to the effect of osteoporosis on the vertebrae.
Certain types of doctors may have more training and experience than others in diagnosing and treating people with osteoporosis. These include a geriatrician, who specializes in treating the aged; an endocrinologist, who specializes in treating diseases of the body’s endocrine system (glands and hormones); and an orthopedic surgeon, who treats fractures, such as those caused by osteoporosis.
Before making a diagnosis of osteoporosis, the doctor usually takes a complete medical history, conducts a physical examination, and orders x rays, as well as blood and urine tests, to rule out other diseases that cause loss vof bone mass.
The doctor may also recommend a bone density test. This is the only way to know for certain if osteoporosis is present. It can also show how far the disease has progressed.
Several diagnostic tools are available to measure the density of a bone. The ordinary x ray is one, though it’s the least accurate for early detection of osteoporosis, because it doesn’t reveal bone loss until the disease is advanced and most of the damage has already been done.
Two other tools that are more likely to catch osteoporosis at an early stage are computed tomography scans (CT scans) and machines called densitometers, which are designed specifically to measure bone density.
The CT scan, which takes a large number of x rays of the same spot from different angles, is an accurate test, but uses higher levels of radiation than other methods. The most accurate and advanced of the densitometers uses a technique called DEXA (dual energy x-ray absorptiometry).
With the DEXA scan, a double x-ray beam takes pictures of the spine, hip, or entire body. It takes about 20 minutes to do, is painless, and exposes the patient to only a small amount of radiation—about 1/50 that of a chest x ray.
In late 2001, Medicare began reimbursing for a test that measures bone resorption, an important measure for tracking a patient’s response to osteoporosis therapy. The relatively inexpensive test measures a baseline amount, then compares amounts from later tests to track progress. The test consists of simple urine collection.
People should talk to their doctors about their risk factors for osteoporosis and if and when to have a bone density test. Ideally, women should have bone density measured at menopause and periodically afterward, depending on the condition of their bones. Men should be tested around age 65. Men and women with additional risk factors, such as those who take certain medications, may need to be tested earlier.
Alternative treatments for osteoporosis focus on maintaining or building strong bones. They include nutritional and herbal therapies and homeopathy.
A healthful diet low in fats and animal products and containing whole grains, fresh fruits and vegetables, and calcium-rich foods (such as dairy products, dark-green leafy vegetables, sardines, salmon, and almonds), along with nutritional supplements (such as calcium, magnesium, and vitamin D) are important components of nutritional approaches to treating this disease.
Women should also eat more soy products such as tofu, soy burgers, or miso. Soy beans contain a substance called isoflavones which have estrogen-like activity.
Isoflavones may help to increase bone density, alleviate hot flashes and other menopausal symptoms, lower the risk of cancer, and even reduce the risk of heart attacks. Natural hormone therapy, such as the use of soy products, is a safer alternative to synthetic estrogenic hormones, which may increase the risk of breast cancer.
In addition, women should avoid foods that may accelerate bone loss. They should avoid having too much salt in their diet, not only because salt raises the blood pressure but also because it may contribute to osteoporosis. They should also cut down on coffee, caffeinated sodas, and alcohol.
High consumption of these beverages, studies have shown, are associated with accelerated drop in bone density and increase risk of bone fracture in old age. Caffeinated sodas are especially bad for the bones because in addition to containing caffeine, they also have high amounts of phosphoric acid. Phosphoric acid increases bone resorption, thus decreasing bone density.
Herbal supplements for osteoporosis emphasize such calcium-containing plants as horsetail (Equisetum arvense), oat straw (Avena sativa), alfalfa (Medicago sativa), licorice (Glycyrrhiza glabra), marsh mallow (Althaea officinalis), and sourdock (Rumex crispus). There are, however, few data from clinical trials to support the use of these herbs.
Homeopathic remedies for osteoporosis focus on treatments believed to help the body absorb calcium. These remedies may include such substances as Calcarea carbonica (calcium carbonate) or Silica (flint). Again, there are few data other than isolated case reports regarding the effectiveness of these remedies.
There are a number of good treatments for primary osteoporosis, most of them medications. For people with secondary osteoporosis, treatment may focus on curing the underlying disease.
For most women who’ve gone through menopause, the best treatment for osteoporosis is hormone replacement therapy (HRT), also called estrogen replacement therapy.
In addition to alleviating hot flashes, synthetic estrogens protect women against heart disease and they help to relieve and prevent osteoporosis. HRT increases a woman’s supply of estrogen, which helps build new bone while preventing further bone loss.
Some women, however, do not want to take hormones because they have been linked to an increased risk of breast or uterine cancer. Other studies suggest that the risk is due to increasing age.
Whether or not a woman takes hormones is a decision she should make carefully with her doctor. Most women take estrogen along with a synthetic form of progesterone, another female hormone. The combination helps protect against cancer of the uterus.
For people who can’t or decide not to take estrogen, two other medications can be good choices. These are alendronate and calcitonin. Alendronate and calcitonin both stop bone loss, help build bone, and decrease fracture risk by as much as 50%.
Alendronate (sold under the name Fosamax) is the first nonhormonal medication for osteoporosis ever approved by the FDA. It attaches itself to bone that’s been targeted by bone-eating osteoclasts. It protects the bone from these cells. Osteoclasts help your body break down old bone tissue.
Calcitonin is a hormone that’s been used as an injection for many years. A new version is on the market as a nasal spray. It too slows down bone-eating osteoclasts. Side effects of these drugs are minimal, but calcitonin builds bone by only 1.5% a year.
Fosamax (alendronic acid) has proven safe in very large multi-year studies, and is now indicated for treatment of osteoporosis in most men. Several medications under study include other biphosphonates that slow bone breakdown (like alendronate), sodium fluoride, vitamin D metabolites, and selective estrogen receptor modulators.
Unfortunately, much of the treatment for osteoporosis is for fractures that result from advanced stages of the disease. For complicated fractures, such as broken hips, hospitalization and a surgical procedure are required. In hip replacement surgery, the broken hip is removed and replaced with a new hip made of plastic, or metal and plastic.
Despite often-successful surgeries, a large percentage of those who survive are unable to return to their previous level of activity, and many end up moving from self-care to a supervised living situation or nursing home. That’s why prevention, getting early treatment, and taking steps to reduce bone loss are vital.
There is no cure for osteoporosis, but it can be controlled. Most people who have osteoporosis fare well once they get treatment. The medicines available now build bone, protect against bone loss, and halt the progress of this disease.
Building strong bones, especially before the age of 35, and maintaining a healthy lifestyle are the best ways of preventing osteoporosis. To build as much bone mass as early as possible in life, and to help slow the rate of bone loss later in life:
Get calcium in foods
Experts recommend 1,500 milligrams (mg) of calcium per day for adolescents, pregnant or breast-feeding women, older adults (over 65), and postmenopausal women not using hormone replacement therapy.
All others should get 1,000 mg per day. Foods are the best source for this important mineral. Milk, cheese, and yogurt have the highest amounts. Other foods that are high in calcium are green leafy vegetables, tofu, shellfish, Brazil nuts, sardines, and almonds.
Take calcium supplements
Many people, especially those who don’t like or can’t eat dairy foods, don’t get enough calcium in their diets and may need to take a calcium supplement. Supplements should be taken with meals and accompanied by six to eight glasses of water a day.
Get vitamin D
Vitamin D helps the body absorb calcium. People can get vitamin D from sunshine with a quick (15–20 minute) walk each day or from foods such as liver, fish oil, and vitamin D fortified milk. During the winter months it may be necessary to take supplements. Four hundred mg daily is usually the recommended amount.
Avoid smoking and alcohol
Smoking reduces bone mass, as does heavy drinking. To reduce risk, do not smoke; and limit alcoholic drinks to no more than two per day. An alcoholic drink is 1.5 ounces of hard liquor, 12 ounces of beer, or 5 ounces of wine.
Exercising regularly builds and strengthens bones. Weight-bearing exercises, in which bones and muscles work against gravity, are best. These include aerobics, dancing, jogging, stair climbing, tennis, walking, and lifting weights.
People who have osteoporosis may want to attempt gentle exercise, such as walking, rather than jogging or fast-paced aerobics, which increase the chance of falling. Try to exercise three to four times per week for 20–30 minutes each time.