Acides gras polyinsaturés à longue chaîne n-3 et risque cardiovasculaire : un mauvais procès d'inefficacité

The purpose of this review is to specify, on the basis of recent studies and in particular of new meta-analyses, the state of art on this subject and the mechanisms underlying these effects. Epidemiology shows a very low prevalence of ischemic heart disease among Inuit in the 50s-70s. Bang & Dyerberg's studies in the 1970s led them to propose the hypothesis that the high levels of n-3 LC-PUFA in traditional Inuit diet were likely to explain this epidemiological finding; the mechanism invoked was the least platelet aggregation. The subsequent westernization of the Inuit lifestyle reflects their increased cardiovascular risk from the 80s. From all cohort studies and randomized clinical trials (RCTs), it appears that if the preventive effects of n-3 LC-PUFA in primary prevention are not formally established, their protective effect in secondary prevention is very real, at least for an intake > 1 g/d of EPA + DHA and more particularly in patients with hypertriglyceridemia (> 1.50 g/L) and/or with a high LDL cholesterol (> 1.30 g/L), even though these patients are treated with many drugs aiming to protect them for a new cardiovascular event. Recently, in addition to nutritional advice on increasing the intake of marine products to reach a daily level > 1 g of EPA + DHA, highly purified and concentrated supplements of EPA ± DHA have been developed. In the USA, new pharmaceutical forms have been accepted by the FDA for the treatment of hypertriglyceridemia at the daily dose of 4 g. RCTs with these new forms are underway to assess their potential benefit in primary or secondary prevention.