The Framingham Heart Study is a long-term, ongoing cardiovascular cohort study of residents of the city of Framingham, Massachusetts. The study began in 1948 with 5,209 adult subjects from Framingham, and is now on its third generation of participants. Prior to the study almost nothing was known about the epidemiology of hypertensive or arteriosclerotic cardiovascular disease. Much of the now-common knowledge concerning heart disease, such as the effects of diet, exercise, and common medications such as aspirin, is based on this longitudinal study. It is a project of the National Heart, Lung, and Blood Institute, in collaboration with (since 1971) Boston University. Various health professionals from the hospitals and universities of Greater Boston staff the project.
In 1948, the study was commissioned by Congress, with a choice made between Framingham, Massachusetts and Paintsville, Kentucky. Framingham was chosen when residents showed more general interest in heart research than Paintsville. Thomas Royle Dawber was director of the study from 1949 to 1966. He was appointed as chief epidemiologist shortly after the start of the project, when it was not progressing well. The study had been intended to last 20 years; however, interest grew in part due to Dr. Dawber's efforts to promote the study and engage in fundraising after he had been transferred to Boston to accept a chairmanship of preventive medicine. By 1968, it was debated whether the original study had served its purpose and should be terminated as scheduled. A committee gathered and considered that, after 20 years of research, the Framingham study should come to an end, since their hypothesis had been tested and extensive information concerning heart diseases had been gathered. Despite this conclusion, Congress failed to accept the recommendation, instead voting to continue the study. The study has been split into different segments, or "cohorts".
The Original Cohort, founded in 1948, consisted of 5,209 men and women.