The Town That Taught America About Heart Disease

In 1948, Public Health Service researchers walked door to door in Framingham, Massachusetts and recruited 5,209 adults aged 30 to 62 to be examined every two years for the rest of their lives. The town was chosen because it was middle-class, mostly white, the right size to track, and 21 miles from the Harvard hospitals where the data would be analyzed. Nobody told the participants what the study was looking for. Nobody knew yet.

Franklin D. Roosevelt had died three years earlier of a stroke at 63. His blood pressure on the day he died was 300/190. His doctors had recorded readings that high for years and treated them as an inevitable feature of executive stress. Heart disease was killing roughly half of American adults, and medicine had no model for what caused it.

Framingham gave them one. The phrase "risk factor" was coined to describe what came out of the data — high blood pressure, high cholesterol, smoking, obesity, lack of exercise, diabetes. None of these connections were obvious in a single patient. They became visible only when you watched 5,000 people over decades and counted who had heart attacks first.

The study added the children of original participants in 1971 and the grandchildren in 2002, building the longest-running multigenerational cardiovascular dataset in the world. Today's risk calculators — the ones your doctor uses to decide whether you need a statin — are still tuned on Framingham coefficients.

The town's main contribution was banal: the same people, measured the same way, for a long time.