In September 1958, a future columnist, then 17, was unpacking as a college freshman when upperclassmen hired by tobacco companies knocked on his dormitory door, distributing free mini-packs of cigarettes. He and many other aspiring sophisticates became smokers. Six years later – 50 years ago: Jan. 11, 1964 – when the Surgeon General published the report declaring tobacco carcinogenic, more than 40 percent of American adults smoked. Today, when smoking is considered declassee rather than sophisticated, fewer than one-fifth do.

In June 1971, a New York couple decided their Bon Vivant brand vichyssoise tasted strange so they put aside their bowls, too late. Within hours he was dead and she was paralyzed from botulism poisoning. And within a month Bon Vivant was bankrupt, proof of the power of health-related information to change Americans’ behavior.

These two excursions into the sociology of health are occasioned by the remarkable recent report of a 43 percent reduction in the obesity rate among children ages 2 to 5. In 2004, about 14 percent of those children were obese; in 2012, about 8 percent were. The New York Times, which showed sound news judgment in making this its front-page lead story, reported that the result of the large federal survey was “a welcome surprise to researchers.”

It was welcome because obesity begins early – those from age 3 to 5 are five times more likely than others to be overweight or obese as adults, when being so makes people more susceptible to cancer, heart disease and stroke. It was a surprise because no one knows why the rate dropped.

A reasonable surmise, however, is that one cause is the cumulative effect of talk about sensible eating and exercising. Certainly one lesson of the last 50 years is that one of the most cost-effective things government does is disseminate public health information concerning behaviors as disparate as smoking and using seat belts.

Mark Twain said humans are the only animals that blush – or need to. Leon Kass, University of Chicago professor emeritus now at the American Enterprise Institute, has written that humans are the only animals that do not “instinctively eat the right foods (when available) and act in such a way as to maintain their naturally given state of health and vigor. Other animals do not overeat, undersleep, knowingly ingest toxic substances, or permit their bodies to fall into disuse through sloth, watching television and riding in automobiles, transacting business, or writing articles about health.”

There may be no such thing as an unmixed blessing, and there was a cost even to the conquest of polio. Americans, whose national DNA disposes them to anticipate progress to be a product of technology, interpreted the Salk vaccine as establishing what can be called the “polio paradigm.” It is the mistaken idea that large improvements in public health result primarily from new medicines.

In 1900, the death rate from tuberculosis was nearly 200 per 100,000; by 1950, after the first effective anti-TB drugs arrived, it was approximately 20 per 100,000. This enormous improvement was largely the result of improved nutrition, housing, hygiene and food handling. Typhoid, too, became rare before effective drugs became available.

Streptomycin may have produced only 3 percent of the reduction of TB but our cultural bias is toward the improved-health-through-medical-intervention model. This produces high-tech, hospital-oriented, disease-and-therapy-centered policy. The premise that health is the product of medicine leads government to believe it can deliver health by judiciously distributing preventive or therapeutic medicines.

A significant portion of America’s health care bill – caused by violence, vehicular accidents, coronary artery disease, lung cancer, AIDS, Type 2 diabetes brought on by obesity, among other problems – results from behavior widely known to be risky. So as we wallow waist deep in the muddy debate about health care, we should remember that the relationship between increased investment in medicine and improvements in health is complex and tenuous.

As Kass has said, in an era of organ transplants and the cracking of the genetic code, it seems boring to suggest that the most important path to health is a vanilla virtue – prudence. Nevertheless, unlike oysters or ostriches or ocelots, featherless bipeds – Plato’s unenthralled description of human beings – are animals that go through their days making choices. And they often make bad ones.

Such choices often require ameliorative medicine. Which illustrates this point: Although preventive medicine is real, society’s level of health does not depend primarily on medicine, which too often must be resorted to when our behavior has forfeited our health.

© 2014, Washington Post Writers Group