Healthy bone is a balancing act. Our bodies continually remove older bone and replace it with new. As adults, if we lose bone at too fast a rate, replace it at too slow a rate, or both, the result is osteoporosis—weak, porous bones that fracture easily. The National Osteoporosis Foundation estimates that nearly 10 million Americans have osteoporosis, and over 43 million more have its precursor—low bone density. The disorder is more common in older than younger people. Fractured bones from this condition can be life-altering, and even life-threatening, but they are not inevitable. There is much we can do to maintain our bones. The earlier we start the better.
What Causes Bone Loss? Bone mass peaks between ages 18 and 25. This peak mass is determined largely by genetics, but nutrition, physical activity, health status during growth, and hormonal and endocrine factors play a role as well. As we age, hormonal changes (particularly menopause); health problems such as thyroid imbalances and digestive disorders; and long-term use of certain medications (including steroids and some heartburn drugs, as well as chemotherapy) all play a role in creating the imbalance that leads to weaker bones. Smoking is associated with lower bone density, as is alcohol abuse. Nutritionally, high salt intake, low calcium intake, and insufficient vitamin D are all associated with higher risk for bone loss, and emerging research suggests other roles for diet as well.