By Nilay Shah
Nilay Shah: What got you interested in public health to begin with?
Jeremiah Stamler, MD: Well, I started out mainly working in animal experimentation, with chickens, feeding [them] cholesterol and salt. We showed that if you feed cholesterol and produce hypercholesterolemia—slight, modest, or marked—you produce atherosclerosis; if you feed salt, you produce high blood pressure; if you gave the two together, you got both. That was the very beginning of the notion of risk factors. My old boss Louis Katz used to say, [a] chicken [is] a very good animal to experiment with—he’s like a human: stands on two legs, eats anything you give him. So I decided we should go from our work to human work. We went to human work in two forms—population studies and clinical trials. So that’s how I got interested in public health, the applicability of these kinds of animal findings to the human scene on a large scale, not only one-on-one with patients, but on populations.
So way back, sixty years ago, we had a director of the National Heart, Lung, and Blood Institute who was an epidemiologist who built cardiovascular epidemiology and sought out young guys in departments with leading figures. Ours was such a department here in Chicago. Louis Katz was a distinguished cardiovascular physiologist [and] electrocardiographer. [He was a] master in those days of all aspects of cardiovascular disease.
Across town at that time was Dr. Oglesby Paul, who was at Presbyterian-St. Luke’s. [He] began the Western Electric study [and] we began the Gas Company study [both looking at coronary heart disease]. [We worked] in parallel, comparing notes, but [keeping the studies] separate. Later on we did a whole bunch of further studies, including the National Cooperative Pooling Project, bringing together our data from several of the first generation of prospective studies—Framingham, Albany, Chicago Gas, Chicago Western Electric – eight or nine [which] we decided could be pooled. Then later on we got involved with a primary screening for recruitment for a multiple risk factor intervention trial. And that gave us a whole quantum leap, because we surveyed 361,662 people—up to then we’d been dealing with four figures in the Gas Company and Western Electric—but now we were dealing with huge numbers. When you look at the relationship of cholesterol to risk, blood pressure to risk, anything to risk, with those kind[s] of numbers, your confidence intervals are very narrow. And as the saying goes, you better believe it!
NS: As you already mentioned, you’ve been involved with a lot of large trials. What has your participation in these large-scale studies taught you about the practice of public health?
JS: Well, public health prior to all of this coming along was more or less identical with sanitation—pure food, pure water, et cetera, and avoiding infectious disease. We helped to transform public health and bring it into the modern world, where the major mass disease problems were not infections and didn’t relate to sanitation, they related to lifestyles, and how do you influence people’s lifestyles: the way people eat, the way people exercise, get people not to smoke, if they want to use alcohol to use it in moderation. A whole new public health emerged. We developed public policy, we fought to get public policy adopted—not an easy fight because of many things, including special interests, who tried to block public policy at the national level in government, the Heart Association, every place where it was crucial to have new public policy.
NS: Can you tell me a little bit more about the struggles that you had to push back against?
JS: Well, what is there to say now in retrospect? We were persistent, we were perseverant, we were a broad array of scientists who had collected data that were impressive and were hard to ignore. As we kept collecting, we got more and more people convinced that what we were talking about made sense. The Heart Association led the way, the federal government was more difficult, because congressmen were always on the backs of the leadership of the National Heart, Lung, and Blood Institute, saying to them, if you go down that road, we’ll [take away] your budget.
NS: Not easy to go up against something like that.
JS: That’s right, it wasn’t about whether the facts were correct, it got down to questions of special interests, and whether the special interest would be served. The initial big one was tobacco, and then later on foods, [which was] much more difficult. And all the usual, of course, “You can’t tell people how to eat,” “You can’t interfere with people’s lifestyle,” “People have rights,” you know. So we developed intellectual responses to all those kinds of arguments, including the right to health, the right to be aware of modern knowledge, supermarkets that are related to modern knowledge, et cetera.
NS: As time has gone by, people have become more cognizant of the benefits of healthy behaviors, but unfortunately, I don’t think the special interests have lost their power.
JS: We have a way to go. We’ve made progress, you know. [T]he Western Electric data [was] the first good nutrition data we got which Dr. Paul collected; it’s a magnificent set of data. Prior to what we had done in the International Population Study of Micro/Macronutrition and Blood Pressure [INTERMAP], it was the best set of nutrition data on an American population ever collected, by a couple of very able, hardworking nutritionists who spent more than 60 minutes with every man in that population study. The data were, you know, 43% of calories [come] from fat—43[%]!
NS: That’s amazing.
JS: Yeah. And 17 or 18% from saturated [fat], 700 or more milligrams of cholesterol a day, polyunsaturated fat low, monounsaturated fat low, it was a disaster! Calories high, 43% of calories from fat! Concentrated calories. Nowadays if you look at the INTERMAP data that we published, the total fat is around 32%, the saturates are down from 17 to about 12%, cholesterol hovers around 100mg per 1000 kilocalories—a lot has happened! A lot more to do, and of course along the way certain aberrations that were not fully anticipated have occurred. You know, we said “reduce fats,” so many of the commercial food processors jumped on the bandwagon with special products that were low [fat] or fat-free, but loaded with concentrated carbohydrates. Certain people blamed the epidemic of obesity on us! You know, “You made these recommendations, people adopted them, and look what’s happened!”
Well, that’s, to put it gently, a half-truth. So, we did make the recommendations, but we didn’t recommend cakes that are low-fat, high-carbohydrate. We recommended fruit, and vegetables, and whole grains, and beans, you now, the kind of food that’s described when you talk about the “Mediterranean diet,” or for that matter, the “East Asian diet.” So, we have a way to go. And we are always up against unexpected, or only partially expected, special roadblocks that the people representing special interests throw our way. But, that’s all right! No progress without struggle.
NS: On that note, in your career, have there been any technological innovations or innovative ideas that have progressed the state of public health?
JS: Well, nowadays it’s so common, but the risk factor concept was a totally new approach. Most of us are trained in science in causation, dealing with simple mechanical causation—you push a board, it moves . . . [and] the cause of the motion of the board is the energy applied by the lever.
Well, cause and effect in biological systems are much more complicated than that. We had to wrestle with “How do you approach causation?” and it had to be on a probabilistic basis, that if you have more of something, you have greater risk. Many people say, well that’s all very nice, all very interesting, but [that has] no application in medicine.
How do you know, if a person has a cough, fever, is spitting blood, he’s got pneumonia? Well, [looking at] thousands of case reports, it’s all based on accumulated experience, to get the best possible diagnosis. So if that’s applicable in diagnosis, why isn’t it applicable to the etiology of disease, which [is also] probabilistic in nature? So we are dealing in probabilities. If you have these exposures, your probabilities are much greater. If you have much less of those exposures, your probabilities are much less.
NS: For those just starting to gain some experience in public health and medicine and research, what advice would you give for launching their careers?
JS: Well, I have a simple piece of advice that applies to research, generally. And that is, don’t pebble pick! A little piece of research here, a little piece of research there, and you publish a paper on each one. Instead, pick an area of work—preferably, pick an area of work that defines a tough, unsolved problem, and tackle it. It’ll be hard, it’ll take many years, but if you make progress in it, because it’s a major problem you’ll make a major contribution. You will create a body of work . . . relating to an important problem. Tackle a big question. Have a lot of fun, and if you have a practical handle on it, if you accumulate information, it becomes impressive.
NS: What about those who are also seeing patients? Although there’s a lot of work left to be done, we know there are things people can do to reduce their risk—diet, exercise, things like that—but some people are reluctant to adopt some of these behaviors.
JS: Yes, well, the effort to modify behavior patterns is a very complex undertaking. If you study the history of public health, at various times when major efforts have been made to modify the way people do things in order to prevent disease, you will find that invariably it’s messy. But that’s the nature of the beast. At a certain point it becomes critical, in my judgment, to get policy at the national level—not just locally or regionally or statewide, but the national level—with resources committed to implement that policy. It’s much easier to get policy than it is [to] get resources for implementing the adoption of that policy.
So, you begin a campaign. I remember when I first started, people used to say, “You know, you’re a crazy optimist—Americans like their fat! They’re not going to give up their fat!” Well, it turned out not to be true! Americans are very health-conscious. Anybody who [has] published a magazine knows, if you want to sell a magazine, you have to have two health articles in it every month. You have to have confidence that the American people are very health-conscious, that they’re interested in trying to stay healthy, and reaching them involves multiple approaches and repetitive messaging—it’s not a short-term thing.
NS: You previously discussed your role in advocating for policy, and the importance of policy for modifying people’s behavior. How do you balance your role as a scientist with your role as an advocate?
JS: Well, some people say a scientist is objective, therefore he cannot be an advocate. One of my colleagues used to say, “I collect the data, and make it available to the public policy people, they do with it what they want.” But he, after time, got furious, and plunged into the battle! And I used to kid him, and say, “Welcome to the battle!” A person who is scientifically objective identifies truth. Truth is not neutral—truth implies certain things. [T]he scientific community as a whole has a responsibility to advocate the application of the knowledge it generates with public dollars to benefit the public. So, I have no trouble with that at all. I can be an advocate for truth—the only thing is I must be careful that the truth is pretty solid, and I’m not going off any deep ends; that’s important. We fought all these battles in the Heart Association with the federal government because there were special interests leaning to fence us in. So I have no trouble being an advocate in favor of data that are solid and just can’t be ignored.
NS: Dr. Stamler, I really appreciate your taking the time to speak with me.
JS: My pleasure.
This interview is the first of a two-part interview with Dr. Stamler.
About the Interview
Jeremiah Stamler, MD
Jeremiah Stamler, MD, is a Professor Emeritus of Preventive Medicine at Northwestern’s Feinberg School of Medicine, and served as the first chair of the Department of Preventive Medicine from 1971 to 1986. He is a foremost authority on the role of salt and fatty foods in hypertension and cardiovascular disease, and is considered one of the fathers of cardiovascular epidemiology and prevention.
Nilay Shah
Nilay Shah is an M4/MPH student at Feinberg. His public health interests are in cardiovascular epidemiology and outcomes research.