What Is Osteoporosis?
Osteoporosis, or “porous bones,” is the weakening of bones caused by an imbalance between bone building and bone destruction. People typically lose bone as they age, despite consuming the recommended intake of calcium necessary to maintain optimal bone health. An estimated 10 million Americans—8 million women and 2 million men—have osteoporosis. Another 34 million have low bone mass, placing them at increased risk for osteoporosis. (1)
Achieving adequate calcium intake and maximizing bone stores during the time when bone is rapidly deposited (up to age 30) provides an important foundation for the future. But it will not prevent bone loss later in life. The loss of bone with aging is the result of several factors, including genetic factors, physical inactivity, and lower levels of circulating hormones (estrogen in women and testosterone in men).
Postmenopausal women account for 80 percent of all cases of osteoporosis because estrogen production declines rapidly at menopause. Of course, men are also at risk of developing osteoporosis, but they tend to do so 5 to 10 years later than women, since testosterone levels do not fall abruptly the way estrogen does in women. It is estimated that osteoporosis will cause half of all women over age 50 to suffer a fracture of the hip, wrist, or vertebra.
How Can Osteoporosis Be Slowed Down?
Preventing osteoporosis depends on two things: making the strongest, densest bones possible during the first 30 years of life and limiting the amount of bone loss in adulthood.
There are a number of lifestyle factors that can help with the latter:
Getting regular exercise, especially weight-bearing and muscle strengthening exercise.
Getting adequate vitamin D, whether through diet, exposure to sunshine, or supplements.
Consuming enough calcium to reduce the amount the body has to borrow from bone.
Consuming adequate vitamin K, found in green, leafy vegetables.
Not getting too much preformed vitamin A.
Preventing Bone Loss in Adulthood
Several complementary strategies can help prevent or minimize bone loss during adulthood and old age. These include:
Getting Regular Exercise
Physical activity that puts some strain or stress on bones causes the bones to retain and possibly even gain density throughout life. Cells within the bone sense this stress and respond by making the bone stronger and denser. Such “weight-bearing” exercises include walking, dancing, jogging, weightlifting, stair-climbing, racquet sports, and hiking.
Swimming is a useful form of exercise for the heart and cardiovascular system. But because water supports the bones, rather than putting stress on them, it’s not considered a good “weight-bearing” exercise for bone strength. In addition, physical activity doesn’t strengthen all bones, just those that are stressed, so you need a variety of exercises or activities to keep all your bones healthy.
Another function of physical activity, probably at least as important as its direct effect on bone mass, is its role in increasing muscle strength and coordination. With greater muscle strength, one can often avoid falls and situations that cause fractures. Making physical activity a habit can help maintain balance and avoid falls.