Dietary n-3 polyunsaturated fatty acids and coronary heart disease-related mortality: a possible mechanism of action

Abstract

Epidemiological and interventional studies indicate that dietary n-3 PUFA reduces mortality due to coronary heart disease (CHD). They act at a low dose, since one or two meals with fatty fish per week is sufficient to provide protection when compared with no fish intake. These fatty acids are effective in providing primary prevention in low- and high-risk subjects and secondary prevention. At high doses, dietary n-3 PUFAs have several beneficial properties. First, they act favourably on blood characteristics: they are hypocholesterolemic and hypotriglyceridemic; they reduce platelet aggregation; they exhibit antithrombotic and fibrinolytic activities; they reduce blood viscosity and they exhibit antiinflammatory action. Second, they reduce ischemia/reperfusion-induced cellular damage. This effect is apparently due to the incorporation of eicosapentaenoic acid in membrane phospholipids. Third, they reduce ischemia and reperfusion arrhythmias. All the effects exerted by n-3 PUFAs at high doses are incompatible with the beneficial action on CHD mortality in humans observed at low doses, where their main properties are related to circulation in the form of free fatty acids. Numerous experimental studies have indicated that low concentrations of exogenous n-3 PUFAs reduce the severity of cardiac arrhythmias. This effect is probably responsible for the protective action of n-3 PUFA on CHD mortality. Further studies are necessary to confirm this assumption in animals. Such studies should take account of the fact that only a low dose of n-3 PUFA (20 mg/kg/day) is necessary to afford protection. Furthermore, since the beneficial effect of n-3 PUFAs on CHD mortality is observed in fish eaters versus no-fish eaters, and since populations in industrialised countries consume excess n-6 PUFAs, control animals in long-term dietary experiments should be fed a diet with only n-6 fatty acids as a source of PUFAs.

LDL cholesteryl oleate as a predictor for atherosclerosis: evidence from human and animal studies on dietary fat

“…Similar outcomes were found in a prospective cohort study, the Physiciansʼ Health Study, whereby dietary fish intake was associated with a reduced risk of sudden death (252%, P 5 0.03). Known biological activities of n-3 PUFAs important in atherosclerosis include cholesterol lowering (usually minor in humans), triglyceride lowering (good at higher doses), decreased platelet aggregation, reduced blood viscosity, favorable decreases in eicosanoid production responsible for vasodilator and antithrombotic properties, and anti-inflammatory effects (33).…”

Effect of dietary fatty acids on expression of lipogenic enzymes and fatty acid profile in tissues of bulls

“…In contrast to SFA, unsaturated fatty acids are recognised as health beneficial. A number of studies demonstrated hypo-cholesterolemic effects of monounsaturated fatty acids (MUFAs) and some polyunsaturated fatty acids (PUFAs) (Demaison and Moreau, 2002). MUFA have also been reported to possess anti-thrombogenic properties (Smith et al, 2003).…”

Acute in vivo administration of a fish oil-containing emulsion improves post-ischemic cardiac function in n-3-depleted rats

“…In some acute clinical situations such as myocardial infarction, it may be advantageous to rapidly modify the n-3 PUFA content in cardiac cell phospholipids; this may not be achieved by oral supplementation with fish oil which generally leads to a significant enrichment after 2 weeks (10). In a recent study on a limited number of patients, Schrepf et al have shown that intravenous (i.v.)…”