A vegetarian diet, quitting cigarettes, moderate exercise and up to an hour a day of yoga meditation can help reverse heart disease symptoms without the use of drugs, according to a California study.

Dean Ornish, a professor of medicine at the University of California, San Francisco, said that instead of using any drugs, his program forced dramatic changes in lifestyle to bring a significant improvement in the health of patients with coronary artery disease.The program is radical, he admits, but for the small group tested, it worked.

"For many who have heart disease," said Ornish, "the conventional therapy (which includes drugs or surgery, some diet revision and exercise) may not go far enough."

Ornish outlined his research in a paper presented Monday at the annual meeting of the American Heart Association.

He devised a strict program that started with a week of training and preparation, a vegetarian diet that was less than 10 percent fat, and 16 hours a week of group therapy. Patients who smoked were required to quit. A moderate exercise program, usually walking, was devised individually for each patient. And, to manage stress, the patients were taught yoga meditation and relaxation exercises.

To test the concept, Ornish put 50 patients with coronary artery disease into two groups. All were tested to find the condition of their arteries, how well their hearts were supplied with blood, and the amount of cholesterol in their bloodstreams. Cholesterol is a fatty material in blood that can lead to clogged arteries.

For those in the first group, Ornish provided the traditional lifestyle care, which included some counseling on how to lower cholesterol levels, control high blood pressure and quit smoking.

The second group, however, was placed on what Ornish called "a very demanding regimen" of lifestyle changes.

"We were asking them to make huge changes in their lifestyle and then evaluated the effects" using high technology X-ray and imaging techniques, he said.

The program started with a seven-day retreat during which the patients were evaluated by a psychologist and by exercise experts.