Dean Ornish says people can reverse heart disease via lifestyle modifications. (ERIK BUTLER)

For years it was thought that bed rest was the best medicine for heart attacks. Then, in the 1950s, the idea of getting patients to move around — at least a little — after an attack became the norm. The 1970s featured highly monitored exercise programs. By the 1990s, the idea became more radical: Patients suffering from coronary artery disease could reverse the condition through diet, exercise and lifestyle changes, without the aid of drugs.

Dean Ornish led the 1990 study that found that a plant-based diet, mild exercise, stress reduction and social support could reduce coronary artery blockages. The study pointed toward a rethinking of the treatment of heart disease through what was called a “diet breakthrough.” Over the years, the evidence has mounted linking these lifestyle factors to improved heart health.

While Ornish’s research offered results, his program was not immediately embraced by all health insurers. He worked for 16 years with the Centers for Medicare and Medicaid Services to create in 2010 a new coverage category called intensive cardiac rehabilitation (ICR), which focuses on comprehensive lifestyle changes. Since then, Medicare has reimbursed costs for Ornish’s Program for Reversing Heart Disease, a 72-hour ICR for people who have had heart attacks, chest pain, heart valve repair, coronary artery bypass, heart or lung bypass, or coronary angioplasty or stenting. (Medicare also pays for ICR programs created by the Pritikin Longevity Center and by the Benson-Henry Institute for Mind Body Medicine at Massachusetts General Hospital.)

Today, Ornish continues to do research at the nonprofit Preventive Medicine Research Institute in Sausalito, Calif., and is a clinical professor of medicine at the University of California at San Francisco. He is also the author of several best-selling books, including “Dr. Dean Ornish’s Program for Reversing Heart Disease,” “Eat More, Weigh Less” and his most recent, “The Spectrum.” In an interview, Ornish discussed the current thinking on reversing heart disease. Here is an edited transcript of the conversation.

Let’s start by defining heart disease.

Coronary heart disease is when the heart can’t feed itself. The heart pumps blood to the body, but it first pumps blood to feed itself through coronary arteries. Over time, if they get clogged, then the heart can’t pump enough blood to feed itself. Blood carries oxygen, and oxygen is fuel for the heart. If the heart doesn’t get enough oxygen, in the short term it can cause angina or chest pain. Over a longer period of time, everything downstream may die and turn into scar tissue; that’s what we commonly refer to as a heart attack. If it’s a small area, you live; if it’s a big area, you don’t.

When someone has a heart attack, the artery may constrict, due to intense emotional stress, a high fat meal, intense exercise. . . . During times of emotional stress, your arteries are supposed to constrict and your blood is supposed to clot faster. We’re really designed to or evolved to deal with acute stresses. You walk into the jungle, the saber-toothed tiger jumps out and either you run or you kill the tiger or the tiger eats you, but one way or another, it’s over. Modern times, these same stresses are so chronic that the mechanisms that are supposed to protect you could kill you.

How does your program help reverse this?

Beginning in 1977, we began publishing a series of clinical research trials, showing for the first time that instead of getting worse and worse, most people could get better and better, if they were willing to make comprehensive changes in diet and lifestyle that went beyond what most [doctors] had been recommending until then. And these include a whole-foods, plant-based diet that’s naturally low in both fat and in sugar and refined carbohydrates; a series of stress management techniques including yoga and meditation; moderate exercise; and what we call psychosocial support, which is another way of saying love and intimacy and community.

Describe how your approach evolved from the limitations of standard care.

When I was a medical student in 1977 . . . we cut people open, we bypassed their clogged arteries, and we’d tell them they were cured. And more often than not, they’d go home and eat the same junk food and smoke cigarettes and not manage stress, not exercise and not have much social support, and more often than not, their bypass grafts would clog up and we’d bypass the bypass, sometimes two or three times. . . . For me, bypass surgery became a metaphor for an incomplete approach, that we were literally bypassing the problem, we weren’t treating the underlying cause.

In lectures, I’ll show a cartoon of doctors busily mopping up the floor [around] a sink overflowing without also turning off the faucet. And it’s a great metaphor — that if you don’t turn off the faucet, if you don’t treat the underlying cause, even if you mop up the floor, even if you do a bypass graft or put a stent in, you’re not changing the underlying condition that led to it and so more often than not, those clog up as well. It’s like changing your oil filter without changing your oil: It just clogs up again. Or when people get put on cardiac drugs or cholesterol-lowering drugs or statins, things like that: What are they generally told, when the patient says, “How long do I have to take this?” And what does the doctor say? “Forever,” right? How long do I have to mop the floor? Forever. Well, why don’t I just turn off the faucet?

What’s been learned about reversing heart disease?

The more people change, the more they improve, at any age, in terms of the amount of blockages in their arteries. The more closely they followed our program, the more improvement they showed. I had thought that the younger people who had less severe disease would do better, but I was wrong. It wasn’t how old they were, it wasn’t how sick they were: Both at one year and at five years, across both groups, the more people changed their lifestyle, the more they improved.

Most docs believe that their patients will take a statin [a cholesterol-lowering drug] but will never change their lifestyle; it’s too hard. And so much of that becomes self-fulfilling. . . . But if you actually go through the evidence with them, say here are the risks, benefits, costs, side effects, of these different approaches, many people will make these changes.

Two-thirds of people prescribed cholesterol-lowering drugs are not taking them four months later; we have 85 to 90 percent adherence to a much more rigorous [lifestyle] program after a year. Even if someone else is paying for the drugs. What I’ve learned is what enables people to make sustainable changes in their lifestyle is not fear of dying, it’s joy of living. Most people for four to six weeks after they’ve had a heart attack, they’ll do pretty much anything that their doctor or nurse advises them to do, but then the fear goes away, the denial comes back and they stop doing it. Whereas when you change your lifestyle . . . most people find they feel so much better so quickly that it reframes the reasons for making these changes. . . . They say, “You know, I like eating cheeseburgers, but not that much. Because what I gain is so much more than what I give up.”

If we say that these lifestyle changes make such a difference in our health, are we also saying that the individual is responsible for making him- or herself sick?

No, I think that’s something that people say periodically. I think that’s just misguided. There’s a big difference between blaming someone and empowering them. . . . It doesn’t mean it’s necessarily your fault, but to the degree that we find that the more you change the more you improve, that’s a very empowering, helpful message to give people.

What has happened in heart disease since you published the study that made headlines in 1990? How has medical knowledge evolved?

I think this idea which was once considered radical is now mainstream. Most doctors believe that heart disease can be reversed by changing lifestyle. The skepticism is, will people do it? And we’ve shown that most people who think they can do it, if given the proper support, can do it. . . . You’re not simply trying to prevent something bad from happening, you’re trying to enhance the quality of your life right now. And if it makes you feel good, it’s sustainable.

So are we saying goodbye to cheeseburgers?

If you don’t have heart disease, it’s not all or nothing. One of the things that we found in all our studies is that the more people change, the more they improve at any age. So it’s not all or nothing, so you have a spectrum of choices, which is why my last book was called “The Spectrum.” And what I did was I categorized foods from the most healthful, Group 1, to least healthful, Group 5. What matters most is your overall way of eating and living. And so indulge yourself one day, eat healthier the next. If you don’t have time to exercise, do a little more the next. If you don’t have time to meditate for an hour, do it for a minute. Whatever you have, there’s a corresponding benefit.

That doesn’t sound quite so daunting.

That’s the point. If you go on a diet, diets are all about what you can’t have and what you must do. Even when you’re eating healthy, people want to feel free and in control. And as soon as I tell somebody, “Never eat this, always eat that,” they immediately want to do the opposite. Sometimes when I lecture, I joke it goes back to the first dietary intervention — you know, when God said, “Don’t eat the apple,” and that didn’t go so well. And that was God talking. Instead of doing that, you say. “Look, this way you can’t fail.” It’s a very compassionate approach. There’s no diet to get on, there’s no diet to get off.

Levingston is a writer in Bethesda.