Acides gras oméga-3 et risque cardiovasculaire

Service d’épidémiologie et santé publique, Institut Pasteur de Lille, Inserm U744, 1 rue du Professeur-Calmette, 59019 Lille cedex, France

^* jean.dallongeville@pasteur-lille.fr

Abstract

Linoleic acid (LA) and alpha-linolenic acid (ALA) are precursors of omega-6 and omega-3 fatty acids. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are synthesized from ALA. These fatty acids play important role in various biological functions. The effects of omega-3 on cardiovascular risk factors – such as lipoprotein levels, blood pressure and glycemia – are very modest at standard low doses, significant only for large intakes. Randomized trials have shown that oils enriched in EPA and DHA have an undeniable impact on heart rhythm. Consumers of long-chain fatty acid have lower heart rates than controls. Conversely, patients with established arrhythmias do not appear to benefit from treatment with these fatty acids. The observation of food habits in population cohorts helped to defined the effects of rich in ALA, EPA, DHA on the risk of myocardial infarction, coronary heart disease and sudden death. For ALA the results are inconsistent and appropriate randomized clinical trials are still conclude. The effects of EPA and DHA are better established. The meta-analysis of cohort studies shows that consumption of omega-3 long- chain (EPA-DHA) reduces total mortality, death from cardiac causes, sudden death and possibly stroke. The data from prevention trials with omega-3 long-chain showed a decrease in coronary events, including fatal, in secondary prevention. These results are relatively consistent to believe that EPA and DHA intake reduces the fatal complications of myocardial infarction. Clinical trials in primary prevention are still missing. However, the sum of evidence support the recommendation for consumption of fish, EPA and DHA in patients at high risk of coronary event.