Medicine: Searching for Life's Elixir: HDL, the good cholesterol

In and around Cincinnati live some 50 families who in an earlier time of myth and legend might have been accused of drinking from Ponce de Leon's fountain of youth. Yet even in today's pragmatic, scientific world, their arteries do seem to carry an elixir of long life. The members of these families, says investigator Dr. Dennis Sprecher of the University of Cincinnati, "typically live for long periods of time, into their 80s and 90s, with very few instances of heart disease, if indeed they have any at all."

Doctors have discovered that these people carry in their blood a component that seems to protect them against the heart disease that plagues many in the Western world, where affluence has made fatty diets and physical inactivity a common way of life. Rose Sweeney, a head nurse at a Cincinnati hospital, is a member of one of the families. "I eat everything I want," she says. "I don't worry about it as far as affecting my heart or building up plaque in my arteries." Sweeney's mother Regina Darpel, 86, notes that other members of her family have lived well into their 90s. She has the same remarkable blood chemistry; so do Sweeney's five children and her sister.

What do these lucky people have in common? They are united in a pact of longevity by the way their bodies process a waxy, odorless substance present in every human being: cholesterol. Cholesterol? The nemesis of every health- conscious person? The object of a swelling tide of medical diatribes against overeating and underexercising? The primary cause of coronary heart disease, which last year caused 1.5 million heart attacks and 550,000 deaths in the U.S.? How can this be? Isn't cholesterol the enemy?

Well, yes. But it is also becoming evident that cholesterol can be either foe or friend, depending on the way it travels through the body. Cholesterol's sinister image derives from the fact that much of the substance is swept through the bloodstream by potentially damaging carrier particles called LDLs (for low-density lipoproteins). LDLs are called "bad" cholesterol because an excess of cholesterol carried by them can lead to the buildup of harmful deposits in the arteries. The other cholesterol carriers, known as HDLs (for high-density lipoproteins), are considered "good" because, far from being killers, they may actually play a vital role in preventing heart disease. They seem to act like biological vacuum cleaners, sucking up excess cholesterol in the bloodstream. It is because the 50-odd Cincinnati families possess unusually high levels of HDL that they are believed to have such a resilient blood chemistry -- and such long lives.