What should I know about bone health?

Prevention is an important focus for every system of the body.  The health of the skeleton is no exception. The spine, the femur (the long bone in the thigh), and other bones must handle a tremendous amount of force throughout a person’s lifetime.  Healthy bone requires a precise balance between bone formation and bone absorption. Bone cells called osteoclasts dissolve and absorb old bone tissue.  Another type of bone cells, osteoblasts, help new bone form in the empty spaces.  This process keeps bones strong.

Around age 30, bone density peaks (i.e., bones are at their strongest).  After that, for most people, it steadily decreases with age. It is vital to pay attention to bone health throughout your life, especially before diagnoses such as osteopenia or osteoporosis are made.  Future bone density is influenced by whether or not your mother had healthy calcium and vitamin D levels, and whether you were breast fed. Children and adolescents must maintain healthy calcium and vitamin D levels to keep bones strong. The first few years of menopause are a time of especially significant bone loss for women. During this time estrogen levels drop and osteoclasts are not held in balance as they were before.  

Why does bone health matter? 

The main concern regarding bone health is to minimize the risk of fractures.  One and a half (1.5) million osteoporosis-related fractures occur in the U.S. each year.  Three hundred thousand (300,000) of them are due to a fall to the hip.  These are costly financially and also affect people’s quality of life.  Five to 20% of people with hip fractures die within one year. Sixty percent who have fractures will need assistance with their daily activities for the rest of their lives.  For more information, see Washington University School of Medicine’s  handout entitled Bone and Mineral Diseases: Facts About Osteoporosis.  (or enter this URL into your browser http://wuphysicians.wustl.edu/dept.aspx?pageID=4&ID=43).

Bone density can be easily measured and responds well to drug treatments.  Therefore, it receives a great deal of attention when bone health is discussed.    However, it is not the only consideration for a healthy skeleton.  Even at ½ bone density, the human spine should be able to maintain five times the amount of weight it normally has to carry.  Why then, do so many people get spine fractures?  Fracture risk seems to be related not only to bone quantity, but also to bone quality.  Fracture risk is greater when both bone density and overall bone quality are low.   This handout suggests ways that you can safeguard the health of your bones.