Osteoporosis and Prevention

As we age, we gradually lose calcium from our bones. The bones become less strong, more brittle, and thus more prone to fracture. This process is called osteoporosis. It occurs particularly rapidly in women after the menopause because estrogen seems to be important in maintaining bone strength. About 650,000 fractures occur each year in the United States as a result of osteoporosis.

Prevention

Exercise (and estrogen supplementation in some women) is required for strong bones. Both work independently. Exercise must be weight bearing so that it stresses the bones and gives a signal to the body to lay down more calcium and strengthen the bones. Walking, jogging and even standing provide such stress. Strengthening the bones of the spine is particularly important because this is the site of over half of the osteoporosis fractures.

Calcium is as important as exercise, but in a secondary sense. Without exercise, calcium is not used by the body; so no matter how much calcium you take in, you don’t get an effect. You need the signals from your bones to the metabolic systems of your body that more calcium is needed; then the calcium is absorbed by the small intestine, transported to the appropriate part of the body, and laid down as new strong bone. Your last two years of exercise are most important; within two years, people who stop exercising lose the benefits. On the other hand, sufficient exercise can maintain bone strength at the normal level of younger life for an indefinite period.