Reprinted from Too Much: An online weekly on excess and inequality

To protect our health, we’ve learned to have our ‘vital signs’ taken. But no visit to a doctor’s office can tell us the vital signs that determine where on earth people can expect to live the longest lives.

Let’s talk life expectancy.

The stats first. They tell a clear story: Americans now live shorter lives than men and women in most of the rest of the developed world. And that gap is growing.

Back in 1990, shouts a new study published last week in the prestigious Journal of the American Medical Association, the United States ranked just 20th on life expectancy among the world’s 34 industrial nations. The United States now ranks 27th — despite spending much more on health care than any other nation.

Americans, notes an editorial the journal ran to accompany the study, are losing ground globally “by every” health measure.

Why such poor performance? Media reports on last week’s new State of U.S. Health study hit all the usual suspects: poor diet, poor access to affordable health care, poor personal health habits, and just plain poverty.

In the Wall Street Journal, for instance, a chief wellness officer in Ohio opinedthat if Americans exercised more and ate and smoked less, the United States would surely start moving up in the global health rankings.

But many epidemiologists — scientists who study health outcomes — have their doubts. They point out that the United States ranked as one of the world’s healthiest nations in the 1950s, a time when Americans smoked heavily, ate a diet that would horrify any 21st-century nutritionist, and hardly ever exercised.

Poor Americans, then as now, had chronic problems accessing health care. But poverty, epidemiologists note, can’t explain why fully insured middle-income Americans today have significantly worse health outcomes than their middle-income counterparts in other rich nations.

The University of Washington’s Dr. Stephen Bezruchka has been tracking these outcomes since the 1990s. The new research published in the Journal of the American Medical Association, Bezruchka told Too Much last week, should worry Americans at all income levels.

“Even if we are rich, college-educated, white-skinned, and practice all the right health behaviors,” he notes, “similar people in other rich nations will live longer.”

A dozen years ago, Bezruchka published in Newsweek the first mass-mediacommentary, at least in the United States, to challenge the conventional take on poor U.S. global health rankings.

To really understand America’s poor health standing globally, epidemiologists like Bezruchka posit, we need to look at “the social determinants of health,” those social and economic realities that define our daily lives.

None of these determinants matter more, these researchers contend, than the level of a society’s economic inequality, the divide between the affluent and everyone else. Over 170 studies worldwide have so far linked income inequality to health outcomes. The more unequal a society, the studies show, the more unhealthy most everyone in it — and not the poor alone.

Just how does inequality translate into unhealthy outcomes? Growing numbers of researchers place the blame on stress. The more inequality in a society, the more stress on a daily level. Chronic stress, over time, wears down our immune systems and leaves us more vulnerable to disease.

This same stress drives people to seek relief in unhealthy habits. They may do drugs or smoke — or eat more “comfort foods” packed with sugar and fat.

Inequality has an equally potent impact on policy decisions around health.

“A substantial proportion of our adult health,” as Stephen Bezruchka explained last week, gets programmed in the early years of a child’s life. Given this reality, guaranteeing every child the best possible supports in the early years ought to be priority number one for any society committed to better health for all.

But unequal nations do precious little of this guaranteeing. The nations with thehighest ranking for child well-being turn out to be the nations with the most equal distributions of income.

Can the United States change course on health? Will Americans in the future be able to look forward to living lives as long as people in other developed nations?

Japan may offer the most encouraging precedent. In the middle of the 20th century, Japan ranked as a deeply unequal and unhealthy nation. But since the 1950s Japan has become a much more equal society, one of the world’s most equal, and, on life expectancy, Japan now ranks number one globally.

The United States, over the same span of time, has gone in the exact opposite direction. We have become the world’s most unequal major nation, with health outcomes among the developed world’s worst.

So how do we start a turnaround? Most Americans, Stephen Bezruchka notes, already understand the concept of “vital signs.”

“We can sense these vital signs tell us something significant about our individual health,” he notes, “every time we step on a scale at the doctor’s office or feel a blood pressure cuff tighten.”

But societies have “vital signs,” too, with none more important to health than our level of inequality. We need to start recognizing these broader “vital signs.” If we do, Bezruchka believes, we can make a difference.

“Dying so much younger than we should,” he sums up, “can be changed.”