In 2009, the British Medical Journal (BMJ) published a study that revealed what seems to be a shocking truth: those who live in societies with a higher level of income inequality are at a greater risk for premature death.

Here in the United States, our high level of income inequality corresponds with 883, 914 unnecessary deaths each year. More specifically, the report concluded that if we had an income distribution more like that of the Netherlands, Germany, France, Switzerland — or eleven other wealthy countries — every year, about one in three deaths in the US could be avoided.

Put that into perspective. According to the Centers for Disease Control (CDC), tobacco, including second-hand smoke, causes approximately 480,000 deaths every year, and in 2010, traffic accidents killed 33,687 people and 31,672 others died of gunshot wounds.

The mechanism by which a bullet or a car crash kills is readily apparent. Inequality is lethal in ways that are less obvious. It’s a silent killer – a deadly plague that we, as a society, tend not to acknowledge.

In Divided: The Perils of Our Growing Inequality, a new book edited by Pulitzer Prize-winning journalist David Cay Johnston, Stephen Bezruchka, a former emergency room physician who is now a professor of public health at the University of Washington, explains the connection. (An excerpt from his chapter titled “Inequality Kills” can be read at Boston Review.)

This week, BillMoyers.com asked Bezruchka about the relationship between inequality and mortality. Below is a transcript of our conversation that’s been lightly edited for clarity.

Joshua Holland: The US is among the richest countries in the world. Before we get into the issue of inequality, how do we stack up when it comes to health outcomes?

Stephen Bezruchka: What we seem to be very good at in this country is dying young. That is, if you look at the average length of life, 35 to over 50 countries do better than we do. The CIA World Factbook counts countries with tiny populations such as Gibraltar and Tristan da Cunha in the South Atlantic, and it comes up with 50. If you take only significant countries, like the UN rankings, then we were 34th in life expectancy in 2011, meaning the citizens of 33 countries have longer average lives. It’s quite startling.

And we not only die younger than people in all the other rich countries; by some measures our overall health is actually on a par with poor countries.

Holland: What’s the link between the very high levels of inequality we see right now and our short average life spans?

Bezruchka: Studies over the last 40 years have demonstrated a very strong link between economic inequality in countries and their health status. So, for example, a meta-analysis — that is, a study putting all the studies on inequality together — by researchers at the Harvard School of Public Health and published in the British Medical Journal concluded that about one death in three can be attributed to America’s high level of inequality. So if you accept the hypothesis, it’s the leading killer.

Holland: This is the only wealthy country without a universal health insurance scheme. Or, if you want to be an optimist about Obamacare, you could say that our universal health insurance scheme is in its infancy. How can we be sure that it’s inequality leading to these poor outcomes, rather than other factors like a lack of access to health care?

Bezruchka: I worked as a clinical doctor for 35 years, as an emergency room physician. So I was the person of last resort. And I can tell you that medical care is a small player in producing good health in societies.

Certainly no more than 10 percent of our health is related to the provision of medical services. Medical care is very good at treating illness and injury, but a lack of medical care is not what causes that illness and injury. That’s something else, and a lot of that relates to inequality.

Holland: What about lifestyle factors? We often hear that Americans are making unhealthy choices — we’re too fat, or we smoke too much, or we drink too much. That would seem to let the systemic issues you’re talking about off the hook.

Bezruchka: Let’s consider what I call the Health Olympics, the ranking of countries by length of life. As I said, we were 34th in 2011. If you look at the countries ahead of us and ask, “out of all those countries, which one has the smallest proportion of men smoking — is it Japan, the longest-lived country?” Well, no, as a matter of fact, out of all the countries on that list, Japan has the highest percentage of men smoking. Close to half of all Japanese men smoke. It used to be almost 80 percent but they’ve been trying to eliminate smoking. And only 20 percent of American men smoke. So Japanese men smoke at twice the prevalence that we do, and yet they’re among the longest-lived. That’s not to say the fact that half of Japanese men smoke is the reason for their good health. But it suggests we have to look at other factors, and smoking is the most obvious and egregious example that I can use to portray that. But the same thing is true for diet and exercise and all the behavioral things we do.

The behaviors that really matter for our health include a range of social connections and family support. The studies and meta-analyses show they’re way more important than smoking and exercise and those kinds of things. And in American society, the economic gap that divides us also limits the range of support that we have. Basically, in a more unequal society, there’s less caring and sharing, and that’s what really matters for your health.

Holland: And you write that there’s a key period in our lives that has a huge impact on our long-term health. Can you tell me about that?

Bezruchka: Studies show that roughly half of our health as adults has been programmed in the first thousand days after conception. In other words, it’s the nine months in the womb, and the next two years after that which are critical for writing the software in our biology that will determine how healthy we’re going to be. So societies that privilege those first thousand days are healthier than societies that neglect them.

What do I mean by privilege or neglect? There are only three countries in the world that don’t have a paid maternity leave policy. One of those countries is Papua New Guinea, half of a big island north of Australia. The second country is Liberia, in West Africa. And you can guess the third. We do not have a federal paid maternity leave policy. All the other countries do, except for those other two. We’re in a league with two countries that aren’t very healthy, and our medical care system isn’t going to bail us out.

All the other rich countries have paid perinatal leave policies, meaning if you’re a working woman and pregnant, you get to take as many as 18 weeks off work with pay.

So what do the healthier countries do? Sweden spends more public money on the first year of life than in any subsequent year. We spend our public money on people my age and older. And what does Sweden do to spend so much money in the first year of life? In Sweden, it is mandatory to take a year’s maternity/paternity leave at full pay — if you have a baby, the mother and father have to take a combined year off. If the mother takes the whole year, then the father’s got to take three months. That’s at full pay. The Swedish government pays you during that period of time, not your employer.

Then, the second year is optional — you can take it off to nurture a baby at 80 percent pay.

In the third year of life, if you want to go back to work, you can put your child in a public daycare center that’s essentially free. And to work in a public Swedish daycare center, you have to have an advanced degree in play. Because what’s daycare all about? It’s about socializing the kids. You need experts.

Contrast that with our expectations — we require only somebody who will work at minimum wage and doesn’t have a recent history of child sexual abuse. That’s all we ask of our daycare workers. So we get what we pay for. We compromise the first thousand days and then we spend a fortune on medical bills later on.

Holland: You write in the excerpt at Boston Review, “There is a dose-response relationship, meaning more inequality leads to worse health.” What are the specific mechanisms that make that the case?

Bezruchka: What happens is those lower down the economic ladder experience more stress. Their lives are much more stressful, and they secrete more stress hormones until they’re burned.

Stress is our twenty-first century tobacco. As we understand more about stress biology and the impact it has on our lives, we are going to have to wage a campaign to reduce the amount of stress in our lives. In one survey, people in the US reported the fourth highest levels of stress in the world. That’s true despite all our smartphones and gadgets and conveniences and the ease of everyday life. It’s incredibly stressful for those who own all these gadgets, but the ones on the bottom suffer the most stress. Surveys of stress hormones find that they have the highest levels and they have the worst health outcomes. So the bigger the gap between the rich and the poor, the greater the stress on those lower down, and the higher you are up the economic ladder, the better off you are.

The interesting thing is that there’s no privileged subpopulation in the United States that has really excellent health. The Institute of Medicine’s “Shorter Lives, Poor Health Report” said clearly, on page three, that even those of us who are white-skinned, college educated and in upper income brackets — and exhibit all the right behaviors — die younger than our counterparts in the other rich countries. And it’s inequality that’s killing us.

Holland: We also work around 30 percent more hours, on average, than the citizens of other wealthy countries, which obviously leads to more stress.

You call poor health outcomes resulting from economic inequality, “structural violence.” Can you explain your use of that term?

Bezruchka: Sure. When we hear the word ‘violence,’ we think of collapsing towers in New York, or you think of somebody with an AR-15 mowing down children in a school. That’s behavioral violence. But if inequality is killing us—one death in three, as I intimated—it’s like an odorless, colorless, highly toxic gas that we’re just not aware of. And it kills us from the usual diseases: heart disease, cancer, diabetes, high blood pressure. It’s the structure of our society, the gap between the rich and the poor, that creates the inequality that kills us from all the usual diseases. And that term came about in about 1969, in the Journal of Peace Research, and they called it ‘structural violence.’

Structural violence kills far more people than the behavioral variety. That’s what we need to change.