This was the first randomized control trial done to see if lifestyle changes could be sustained and if they halt or reverse coronary artery disease. The trial covered a 5 year period from 1986 to 1992 and involved 28 patients in the experimental group and 20 in the control group. The study patients were exposed to 4 interventions: a low-fat vegetarian diet, aerobic exercise, stress management, and group psychosocial support. Using sophisticated coronary angiography to measure the diameter of coronary arteries at 1 and 5 years, Dr. Ornish discovered that there was regression of coronary lesions and improved perfusion of the heart muscle after 1 and 5 years in his experimental group. In fact, the more closely one followed the lifestyle, the better the results. During this same time period, patients in the control group who were getting the usual care from their doctors had progression of their disease and more cardiac events.
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Ornish D, Scherwitz L, Billings J, et al. Intensive lifestyle changes for reversal of coronary heart disease Five-year follow-up of the Lifestyle Heart Trial. Journal of the American Medical Association. 1998; 280: 2001-2007