That may sound like good advice. Except, of course, if what ain't broke actually is broke, but it ain't visible.

For example, where people are undernourished throughout a good part of their lives, they will tend to have a shorter life span than would have occurred with optimal nutrition. So although the problem here wasn't immediately apparent, it was one that did need to be fixed.

Many post-menopausal women are at risk for osteoporosis. Here again, there is no obvious problem, nothing that is in apparent need of being fixed. Nothing, that is, until the bone density diminishes to the point at which a slight bump or slip is enough to cause a broken hip or pelvis. But by then it may be too late, because fixing the problem at that stage will not be so easy.

We tend to take our bones for granted. They are hidden away inside the flesh, out of sight. Yet they are so necessary, providing a framework for the body and a protective cage of sorts for the vital organs within. But out of sight though they may be, age is ever working on our bones.

When we are young our bones are growing and strengthening, doing so at the bidding of osteoblasts, which are bone growth stimulators. This brings about the growth of children into adults. Past the age of thirty, our bones are subject to a preponderance of osteoclasts, which promote bone absorption. During much of adulthood, the two are in approximate balance.