How To Keep The Doctor Away

By MICHAEL D. LEMONICK

At the dawn of the 20th century, the roster of illnesses that spelled almost inevitable death seemed to stretch forever. Cancer, heart disease, kidney disease, cirrhosis, pneumonia, cholera, diphtheria, tuberculosis and even the flu were relentless killers. Some victims might hang on to eke out a normal life span, albeit in disability and pain; some might even recover entirely. But survival was purely a crapshoot, with depressingly unfavorable odds. The hospital was a place where people went to die, not to be cured.

Today the medical landscape has been transformed beyond recognition. The drugs are smarter, the surgical tools more powerful, the diagnostic tests astonishingly precise. Today most of the deadliest diseases of 1900 are routinely cured or managed, and it's the choice not to be hospitalized that's often a decision to give up on life.

But curing disease is only part of what makes modern medicine so remarkable--and maybe not the most important part. Triumphing over sickness is a wonderful thing, but it's far better never to get sick at all. And while some scientists have been making headlines with ever more dramatic chemical and surgical interventions, others have been working quietly to prevent disease in the first place.

The new science of prevention draws on breakthroughs in our understanding of how the body works at all levels, from gross anatomy to molecular biology. Equally important, researchers are beginning to understand how the body's systems--immune, nervous, endocrine--affect one another. Scientists have uncovered secrets about how exercise and nutrition can stave off everything from heart disease to aging. They're working on vaccines for AIDS, malaria, TB and even cancer. They're learning--most recently in the post-Sept. 11 anthrax attacks--how the judicious use of antibiotics can prevent disaster (and how abusing those medicines can cause it). In the wake of America's crash course on bioterrorism, they're pushing to revitalize the nation's once powerful public health network--the early-warning system that can keep us safe from microbes, both natural and weaponized.

In the pages that follow, you'll be introduced to the strategies that are remaking medicine just as profoundly as any discovery of the past 100 years. If the 20th century was the age of astonishing cures, the 21st may turn out to be the era in which those cures became irrelevant.

--By Michael D. Lemonick