Read the text below and answer the following question based on it.
In a prospective, randomised, controlled trial to determine
whether comprehensive lifestyle changes affect coronary
atherosclerosis after 1 year, 28 patients were assigned to an
experimental group (low-fat vegetarian diet, stopping
smoking, stress management training, and moderate
exercise) and 20 to a usual-care control group. 195
coronary artery lesions were analysed by quantitative
coronary angiography. The average percentage diameter
stenosis regressed from 40.0 (SD 16.9)% to 37.8 (16.5)% in
the experimental group yet progressed from 42.7 (15.5)% to
46.1 (18.5)% in the control group. When only lesions greater
than 50% stenosed were analysed, the average percentage
diameter stenosis regressed from 61.1 (8.8)% to 55.8
(11.0)% in the experimental group and progressed from
61.7 (9.5)% to 64.4 (16.3)% in the control group. Overall,
82% of experimental-group patients had an average change
towards regression. Comprehensive lifestyle changes may
be able to bring about regression of even severe coronary
atherosclerosis after only 1 year, without use of lipidlowering drugs