Americans are living longer than ever. As the population ages, many senior citizens are burdened with chronic illnesses, but many others remain healthy and active. When scientists investigate aging, they have to distinguish between changes caused by disease and those caused by aging itself. It's important research: among other things, it has taught us that men who take care of themselves can prevent many of the illnesses that make less prudent gents old before their time.

Until recently, research on aging has focused mainly on crucial things that go wrong — on heart disease, mental decline, arthritis, prostate woes, and ...

It's easy to dismiss hay fever as a minor nuisance. But call it by its proper name, allergic rhinitis, and you'll be on the way to recognizing it as a legitimate medical problem. Add the fact that it affects about one of every five Americans and drains the economy of about $2 billion a year, and you'll see that it's an important problem indeed. Fortunately, it's also a problem that responds very well to treatment.

Nosing aroundIf a man thinks about his nose at all, he's likely to think of it as a simple organ of smell. It's true, of course, ...

As a group, the six statin drugs are the best-selling prescription medications in the United States. It's no surprise, since heart disease remains America's leading cause of death. Statin therapy reduces the risk of heart attacks and other clinical manifestations of coronary artery disease by up to 37%, with most of the benefit going to men at high risk.

All the statins lower LDL ("bad") cholesterol by inhibiting HMG-CoA reductase, the enzyme that liver cells use to manufacture cholesterol. The drugs also trick the liver into removing cholesterol from the bloodstream, adding to the cholesterol-lowering benefit. In addition, the statins ...

On call Vegetarian diets Q. Following the lead of our 12-year-old daughter, my wife has become a vegetarian. She says she's willing to continue serving meat and chicken, but I sense that she'd rather not. What can you tell me about the safety of a vegetarian diet?

A. Most people who choose vegetarian diets are motivated by their personal philosophies, ethical beliefs, or religious convictions. But health certainly is a factor, and if a vegetarian eating plan is constructed properly, it can be an asset to health.

Variations on a theme Many people who eschew animal foods think of themselves ...