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Framingham Heart Study director Daniel Levy’s new book
A change of heart, a revolution in medicine
By Brian Fitzgerald
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MED Professor Daniel Levy (MED’80), director of the Framingham Heart Study. Photo courtesy of Alfred A. Knopf, Publisher |
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Some 57 years ago, doctors began physical examinations and lifestyle interviews of more than 5,200 residents between the ages of 30 and 62 in the town of Framingham, Mass. The Framingham Heart Study was born: the first major study to apply an epidemiologic approach to seek out the causes of cardiovascular disease on a population base.
Prior to the study, epidemiology dealt primarily with the spread of infectious diseases. In 1948, however, the National Institutes of Health’s National Heart Institute — now the National Heart, Lung, and Blood Institute (NHLBI) — wanted to investigate the noninfectious disease that had become the nation’s number-one killer: heart disease.
Little was known about the general causes of heart attack and stroke in 1948. However, nearly six decades and 1,300 scientific papers later, the risk factors behind cardiovascular disease are common knowledge thanks to the study.
Since 1971, the NHLBI has conducted the Framingham Heart Study in conjunction with Boston University. Daniel Levy, a MED professor of medicine, joined the study in 1984 and took over as director in 1995. With Susan Brink, a senior writer for U.S. News & World Report, Levy (MED’80) recently wrote a book: A Change of Heart: How the People of Framingham, Massachusetts, Helped Unravel the Mysteries of Cardiovascular Disease. The book, an assessment of the achievements and challenges of the study to date, also describes its continuing importance.
In an interview with the B.U. Bridge, Levy talks about the history of the study and what to expect in the future as it finishes screening the third generation of participants: 4,100 of the original enrollees’ grandchildren.
B.U. Bridge: What are the Framingham Heart Study’s major accomplishments?
Levy: One of the first, and to this day still one of the most important, outcomes of the study was the identification — or at least the confirmation — of many of the key risk factors for heart disease: high blood pressure, high cholesterol levels, diabetes, smoking, obesity, a sedentary lifestyle. And because of data from the study, we split the cholesterol up into LDL, or bad cholesterol that builds up plaque in artery walls, and the principal protective component, HDL cholesterol.
A lot of what we learned early on about these so-called risk factors came from the Framingham Heart Study. Even the very term risk factor was coined largely by Thomas Dawber [former chair of MED’s department of preventive medicine and epidemiology] and Bill Kannel [a MED professor], two former directors of the study.
B.U. Bridge: You begin the book with an account of the death of President Franklin Roosevelt, who succumbed to a stroke in 1945. Why weren’t his doctors concerned about his high blood pressure?
Levy: It’s absolutely striking when you go back and look at the facts of the case. Today, anyone, no matter how poor and how underserved, would get medical care that is 1,000 times better than what the president of the United States got in 1945, and years before his death as well. Part of that was because back then people didn’t know about the risks associated with high blood pressure and there was almost nothing available to treat it.
B.U. Bridge: Why have cardiovascular disease rates increased so steadily since the beginning of the last century, and especially after World War II?
Levy: We did everything we could to engineer exercise out of our lives. We invented gas-powered lawnmowers to replace the hand-pushed ones, and when the powered mower wasn’t enough, we engineered self-propelled power mowers, and then riding lawnmowers. We invented new washing machines that took the elbow grease out of doing the daily laundry, and dryers instead of the old-fashioned hand-wringers that people used to dry their clothes. We used a lot of our ingenuity to engineer exercise out of our lives. And prosperity meant that people who couldn’t afford cars before could now afford them, and families could afford not only one car, but two. We then engineered a device that ensured that people stayed home and didn’t exercise: the television. Instead of going out for social occasions, such as dancing, people sat home and watched it all on TV. We really became a sedentary society — a generation of couch potatoes, as we say in the book. And because of our prosperity, we also consumed a progressively worse diet of meals full of saturated fat and cholesterol.
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A nurse weighs a patient during the early years of the Framingham Heart Study. At present, the program is screening the third generation of study participants: more than 4,000 of the original enrollees’ grandchildren. Photo courtesy of the Framingham Heart Study archives |
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B.U. Bridge: In 1948, didn’t some physicians actually think exercise was bad for your health?
Levy: One of the protagonists in the book is Paul Dudley White, the cofounder of the American Heart Association. Today we know his name in Boston because there is a bicycle path along the Charles River named after him. Back when the study began, Paul Dudley White was regarded by many as an oddball because he was one of the few professionals who bicycled to work for exercise.
We’ve learned so much over time. A main focus of the book is this journey from ignorance to knowledge that we’ve been on for the last half-century. Most people don’t appreciate that it took a heroic effort to learn as much as we know today about heart disease. We take so much for granted. The discovery of the causes of heart disease should be every bit as exciting and considered as much of a landmark of science as some of the things that have gotten a lot of newspaper headlines, such as the first heart transplants. But when hundreds of thousands of people don’t develop the complications of heart disease because of the advances that have taken place in prevention and treatment, that doesn’t make many headlines. A message that I want to convey with the book is that the Framingham Heart Study may have been largely unheralded in the field of medicine, but by no means should it be regarded as an unimportant one. It has changed lives all over the world.
B.U. Bridge: Are you still expecting valuable data from the study?
Levy: My colleagues and I spend an enormous amount of time and thought trying to consider what Framingham can contribute to public health in the future. While it has contributed a lot in the past, we also think that its future is brighter than ever. In 1971 we added another cycle of about 5,000 participants — children of the original enrollees. We’ve now completed the recruitment of the third generation of study participants. A lot of those studies are still being analyzed to learn more about the common conditions that affect people, such as high blood pressure, obesity, diabetes, lung disease, to name just a few of the things we will be looking at intensively.
We approached the recruitment of the third generation with the notion of looking at family patterns of disease and ultimately with the objective of trying to identify some of the genetic factors of heart disease — and simply being able to identify genes that appear to promote obesity, high cholesterol levels, high blood pressure, or asthma. This may facilitate the development of treatment — 5, 10, or 20 years from now — to reduce some of the complications associated with those conditions.
B.U. Bridge: Despite all we’ve learned from Framingham, we hear talk of an obesity epidemic. What are the repercussions of this?
Levy: In a couple of chapters in the book we look at obesity and dietary issues. The rates of obesity have been rising to a startling degree in the United States in the last 20 to 30 years, and the group most affected is America’s children. The rates of childhood obesity have tripled during this period. At a time we have so much to be proud of in our efforts to combat high blood pressure, high cholesterol levels, and getting people to quit smoking, the one risk factor that’s moving in the wrong direction is obesity. The rising rates of obesity are dragging with them increasing risks for diabetes, for example. The epidemic we face with obesity in the United States threatens to negate much of the remarkable progress we’ve made over the last 30 years with regard to the other modifiable risk factors. We must do something about this problem on the national level.
29
April 2005
Boston University
Office of University Relations