By: Thomas Pickering, MD, DPhil, FRCP, Director of Integrative and Behavioral Cardiology Program
of the Cardiovascular Institute at Mount Sinai School of Medicine, New York.

Dr. Dean Ornish is well known for his tireless promotion of the benefits of intensive lifestyle changes for preventing and reversing coronary heart disease. These include quitting smoking, regular exercise, a diet that contains only 10% fat and stress management training. He set up the Lifestyle Heart Trial in an attempt to document these benefits, in which patients who already had coronary heart disease proven by coronary angiograms were randomly allocated to his intervention program or to 'usual care'. To be included in the study, the patients not only had to agree to take part in the intervention program, but also to have repeat angiograms at one and then five years after starting the program. Out of 93 eligible patients, 20 completed the study in the Intervention group; and 15 completed the study in the control group. Records of the amount of exercise, the frequency of stress management sessions, and diet were kept in both groups. The angiograms were analyzed to whether the narrowing from plaque in the coronary arteries had got better or worse. These narrowings occur at discrete points in the arteries, and one artery may have several narrowings. Their size is measured as the percent of the diameter of the artery that they block: thus 0% implies no narrowing, and 100% implies complete blocking.

The main finding was that patients in the Intervention group showed a reduction in the severity of the narrowings from an 40% average to 37%. In contrast the patients in the control group showed a progression of their narrowings from 41% to 52%. Furthermore, changes in the patients in the Intervention group measured on the angiograms were related to how intensively they had followed the program: the six patients who followed it most closely showed a nearly 7% reduction in their narrowings; however, the ones who were the least adherent showed virtually no change. In addition the likelihood of having new heart problems requiring admission to hospital was reduced by 50% in the Intervention group. None of the patients in the Intervention group took lipid-lowering drugs, whereas several of the ones in the control group did.

Doctor's comments

This is the most convincing demonstration to date that an intensive lifestyle program can halt and even reverse the progression of plaques in the coronary arteries, which if unchecked, will lead to complete blockage of the artery and, hence, a heart attack or even death. The findings are particularly impressive, in view of the fact that the patients in the control group who were taking lipid-lowering drugs did less well than patients in the experimental group, who achieved their results without the use of drugs.

The lifestyle changes needed to achieve these results are, however, very demanding on the patient. The average amount of exercise done by the patients in the intervention group was five hours per week at one year, and three and a half hours at five years. They also spent one and a half hours a day practicing stress management at one year, and just under an hour a day at five years. They also adopted an almost wholly vegetarian diet, with fat consumption decreasing from 30% of energy intake to 8%. Nobody knows if the same benefits could be achieved just with the diet and exercise.

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