Osteoporosis (or porous bone) is a disease in which bones become weak and are more likely to break (or fracture). Without prevention or treatment, osteoporosis can progress without pain or a symptom until a fracture occurs. Fractures commonly occur in the hip, spine, and wrist.
Osteoporosis is the underlying cause of more than 1.5 million fractures annually (300,000 hip fractures, approximately 700,000 vertebral fractures, 245,000 wrist fractures, and more than 300,000 fractures in other areas). The estimated national cost (hospitals and nursing homes) for osteoporosis and related injuries is $14 billion each year in the United States.
Osteoporosis is not just an โold womanโs disease.โ Although it is more common in white or Asian women older than 50 years, osteoporosis can occur in almost any person at any age. In fact, more than 2 million American men have osteoporosis, and in women, bone loss can begin as early as age 25 years. Building strong bones and reaching peak bone density (maximum strength and solidness) can be the best defense against developing osteoporosis. After reaching the peak, which usually occurs by the age of 30, a healthy lifestyle can help keep bones strong.
Osteoporosis is more or less preventable for most people. Prevention is very important because, while treatments are available for osteoporosis, no cure currently exists. Prevention of osteoporosis involves several aspects, including nutrition, exercise, lifestyle, and early screening.
Nutrition and Osteoporosis Prevention
Eating the right foods is essential for good nutrition. Our bodies need the right vitamins, minerals, and other nutrients to stay healthy. Getting enough calcium and vitamin D is important for strong bones as well as for proper function of the heart, muscles, and nerves. The best way to get enough calcium and vitamin D is through a balanced diet.
A diet high in calcium
Not getting enough calcium during a lifetime significantly increases the risk of developing osteoporosis and is associated with low bone mass, rapid bone loss, and broken bones. A diet high in calcium is important (see Osteoporosis and Calcium). Good sources of calcium include low-fat dairy products, such as milk, yogurt, cheese, and ice cream; dark green leafy vegetables, such as broccoli, collard greens, and spinach; sardines and salmon with bones; tofu; almonds; and foods with added calcium, such as orange juice, cereals, soy products, and breads. Calcium supplements and vitamins are also available.
Recommended Calcium Intake by the National Academy of Sciences (1997)
Age mg/day Birth-6 months 210 6 months-1 year 270 1-3 years 500 4-8 years 800 9-13 years 1300 14-18 years 1300 19-30 years 1000 31-50 years 1000 51-70 years 1200 70 years or older 1200 Pregnant or lactating See ages above
A diet high in vitamin D
Vitamin D is important for the body to absorb calcium from the diet. Without enough vitamin D, the body is unable to absorb calcium from the foods that are eaten, and the body has to take calcium from the bones, making them weaker. Vitamin D comes from 2 sources. It is made in the skin through direct exposure to sunlight, and it comes from the diet. Many people get enough vitamin D naturally. Vitamin D is also found in fortified dairy products, egg yolks, saltwater fish, and liver. However, vitamin D production decreases with age, in people who are housebound, with the use of sunscreens, and during the winter when sun exposure is decreased. In these cases, people may need vitamin D supplements to ensure a daily intake of 400-800 IU of vitamin D.
Exercise and Osteoporosis Prevention
Exercise is important to prevent osteoporosis. Although bones may seem like hard and lifeless structures, bones are more like muscle; bones are living tissue that respond to exercise by becoming stronger. Physical activity during childhood and adolescence increases bone density and strength. This means that children who get exercise are more likely to reach a higher peak bone density (maximum strength and solidness), which usually occurs by age 30 years. People who reach higher peak bone densities are less likely to develop osteoporosis.
The best exercise to prevent osteoporosis is weight-bearing exercise that works against gravity. Weight-bearing exercises include walking, hiking, jogging, climbing stairs, playing tennis, jumping rope, and dancing. A second type of exercise is resistance exercise. Resistance exercises include activities that use muscle strength to build muscle mass, and these also help to strengthen bone. These activities include weight lifting, such as using free weights and weight machines found at gyms and health clubs. Exercise has additional benefits in older people as well because exercising increases muscle strength, coordination, and balance and leads to better overall health (see Fall Prevention and Osteoporosis).
Elderly people, people with osteoporosis, people with heart or lung disease, and people who have not exercised for most of adulthood should check with their healthcare provider before beginning any exercise program.
Lifestyle and Osteoporosis Prevention
Quit smoking
Limit alcohol intake
Regular consumption of 2-3 ounces of alcohol a day may be damaging to bones, even in young women and men. Heavy drinkers are more likely to have bone loss and fractures. This is related to both poor nutrition and increased risk of falling.
Therapeutic medications
Currently, bisphosphonates, such as alendronate (Foamex), risedronate (Atonal), and ibandronate (Bonita) are approved by the US Food and Drug Administration (FDA) for the prevention and treatment of postmenopausal osteoporosis in women. As men age, they are also susceptible to osteoporosis. Alendronate is approved to increase bone mass in men with age-related osteoporosis. Alendronate and risedronate are approved to treat men and women with steroid-induced osteoporosis. Adequate calcium and vitamin D intake is essential for bisphosphonates to be effective.
Raloxifene (Vista) is approved for the prevention of osteoporosis only in postmenopausal women who are not taking hormone replacement therapy. Teriparatide is approved for the treatment of the disease in postmenopausal women and men who are at high risk for fracture. Estrogen/hormone therapy (ET/HT) is approved for the prevention of postmenopausal osteoporosis, and calcitonin is approved for treatment. Both alendronate and risedronate are approved for use by men and women with glucocorticoid-induced osteoporosis.
Estrogen/hormone therapy
After menopause, bone strength and density decreases rapidly in women. Studies show that estrogen therapy/hormone therapy (ET/HT) reduces bone loss, increases bone density in both the spine and hip, and reduces the risk of broken bones (especially the hip and spine). Currently, ET/HT is approved to prevent osteoporosis from developing after menopause. This therapy is most commonly available in the form of a pill or skin patch. See Hormone Replacement and Osteoporosis for more information.
When estrogen therapy (ET) is taken alone, it increases a womanโs risk of developing cancer in the uterus (cancer of the uterine lining, called endometrial cancer). Therefore, for women who have not had their uterus removed (have not had a hysterectomy), doctors prescribe an additional hormone, either natural progesterone or a synthetic similar substance called progestin. Progestin or progesterone in combination with estrogen is called hormone therapy (HT), and it reduces the risk of endometrial cancer in women who have not had a hysterectomy. A large study from the National Cancer Institute (NCI) has recently indicated that long-term use of ET (estrogen alone) may also be associated with an increase in the risk of ovarian cancer.
The Womenโs Health Initiative (WHI) study recently demonstrated that HT is associated with increases in the risk of breast cancer, ovarian cancer, stroke, and heart attack. No studies have determined whether ET (estrogen alone) is associated with an increase in the risk of breast cancer or whether it has an effect on cardiovascular events (like heart attack).
Doctors should prescribe any estrogen therapy only for the shortest period of time possible. ET/HT used to prevent osteoporosis after menopause should only be considered for women with menopausal symptoms who at significant risk of developing osteoporosis, and other nonestrogen medications should be considered if osteoporosis is the primary concern.