If you think of your body as a building, your bones are the framing. Without strong bones the whole thing would collapse. And that's a good analogy for what happens when we don't take good care of our bones. Over time, the body loses more and more bone, until we develop osteoporosis and it "collapses," in the form of bones fracturing.
About half of all women over 50, and about one out of every four men, will break a bone because of osteoporosis, a condition of weakening bone that affects about 10 million Americans, with some 34 million more at risk.
A bone density scan can detect thinning bones at an early stage. If you already have osteoporosis, bone scans can also tell you how fast the disease is progressing.
But an abnormal bone scan can create as many questions as it answers. Who should get a bone density scan, and what do the results mean? If your bone density is below normal, what can you expect, and what should you do?
During childhood and adolescence, your body makes bone tissue (formation) faster than you lose it (resorption). By the time you're 18 to 20 years old, you've built up about 90% of all the bone you'll ever have. Most people continue to build bone faster than they lose it until about age 30, a point that's known as “peak bone mass.” From then on, the rate of bone building slows down and the rate of bone loss picks up.
You can't get back bone once it's lost, but you can help maximize bone formation and minimize bone loss, which can lead to osteoporosis. Researchers estimate that things you have no control over -- such as genetic factors, sex, age, and race -- control about 50% to 90% of your bone mass. But you can help protect your bones and reduce the risk of osteoporosis in two key ways: nutrition and exercise.
Nutrition for Strong Bones
If you want to build stronger bones, you need three key elements: calcium, protein, and vitamin D. Bones are largely made up of a protein -- collagen -- bound together by calcium and other trace minerals). Vitamin D helps your body absorb calcium so it can do its job building strong bones.
In 2010, the Institute of Medicine released new guidelines as to just how much calcium and vitamin D people need. Most adults, should get between 600 and 800 international units (IUs) of vitamin D every day, and between 1,000 and 1,300 milligrams (mg) of calcium daily The higher levels are for postmenopausal women, adolescent girls, and women who are pregnant or nursing.
“It's pretty easy to figure out how much calcium you're getting,” says Deborah Sellmeyer, MD, medical director of the Johns Hopkins Metabolic Bone Center. “Just from eating random, non-calcium-rich foods, your diet contains about 250 mg of calcium daily. To get up to what you need -- whether it's about 1,000 for the average adult, or higher for adolescent girls and postmenopausal women -- you'll need to add more calcium-rich foods.”
There are lots of ways to get plenty of calcium in your diet. Dairy products like milk, yogurt, and cheese have plenty of calcium, as well as protein. “But you don't have to be a dairy person to get good dietary sources of calcium,” Sellmeyer says. Other options include: