"Drink your milk" applies to everyone

On page D1 of today's WSJ, Jacob Goldstein reminds us that boys should drink milk too. Why? Men over 50 have, on average, a 25% chance of developing osteoporosis (granted, women's risk is double that). Some risk factors: increased age, lighter weight, "history of chronic obstructive pulmonary disease" (COPD, for you acronym-happy readers), and "smoking and excessive drinking." Also, certain cancer-treating drugs (e.g. Lupron for prostate cancer) that block hormones do damage to one's bones.

Getting enough calcium and vitamin D helps. And exercise during childhood and adolescence, while the skeleton is still growing, builds bone. That's important because it helps raise the so-called peak bone mass reached during young adulthood, before the long-term decline in bone mass begins. "The less you start with, the less you're going to end up with when you're really at the age when osteoporosis risk is very important," says Eric Orwoll of Oregon Health & Science University, who is conducting a long-term study of osteoporosis in men.

Staying fit into old age is also important; it means stronger muscles and better coordination and balance, all of which help avoid falls, a key trigger for fractures in the elderly.

There is some evidence that the type of exercise -- weight-bearing, versus non-weight-bearing -- can make a difference for bones. For example, some research suggests competitive cyclists, who spend hours a week on their bicycles but little time running or jumping, may tend to have weaker bones than runners...

Some experts nevertheless say that the more important point is simply to exercise. "I have not been convinced that the tiny increase in bone density [from weight-bearing exercise] is really that critical," Dr. [Ethel] Siris says. "If my patients say, 'I don't enjoy weight-bearing exercise, should I swim?' I say, 'Yes.' "