[Are there environmental protective factors?].

Protective factors against atherosclerosis are a group of different elements which include the fatty acids, alcohol, antioxidant vitamins, dietary fibres and physical exercise. Unsaturated fatty acids, especially alpha-linolenicacid have a beneficial effect on the coronary vessels. Alpha-linolenic acid is associated with low coronary mortality both in cohort studies (the Seven Countries Study) and in secondary prevention (Lyon Diet Heart Study). There is an inverse relationship between moderate alcohol consumption and coronary artery disease with a reduction of risk of about 30% in all prospective studies. High dietary intake of vitamin E was found to be associated with a decreased coronary risk. On the other hand, dietary supplements of vitamin E in primary and secondary prevention were associated with increased cardiovascular mortality. Folates have a protective effect by their action on homocysteine metabolism. There is no formal proof at present in favour of the systematic introduction of the B vitamins in primary or secondary prevention. Fresh fruit and vegetables seem to be protective by their fibre and vitamin B content. Moderate endurance physical exercise is a protective factor in all studies. Its beneficial effects in function and rehabilitation are well documented. In primary prevention studies, exercise has a beneficial effect but criteria of duration and frequency remain vague. Therefore, there are environmental protective factors against atherosclerosis which allow physicians to introduce a positive note in these recommendations.