Mechanisms underlying the cardioprotective effects of omega-3 polyunsaturated fatty acids.

Key Findings:

This paper reviews the physiological significance of omega 3 fatty acids and describes their metabolic functions. Blood pressure, left ventricular diastolic filling, heart rate and endothelial function are improved with omega 3. The cardioprotective effects of omega-3 involve arrhythmia prevention, plasma triacylglycerol reduction, vascular relaxation improvement, anti-inflammatory responses, platelet aggregation inhibition, enhancement of plaque stability and anti-atherosclerotic effects. Consumption of high amounts of saturated, trans, and omega-6 fats, and low amounts of omega 3 (approx. omega 6/omega 3 ratio of 16:1) is typical in today’s diet. Ancestral diets had an omega 6/omega 3 ratio of about 1. An imbalance of this ratio may result in altered gene regulation. Omega 3 act to reduce CVD in a number of mechanisms that involve TG lowering, anti-inflammatory, inflammation-resolving, regulation of transcription factors and gene expression, membrane fluidity and antiarrhythmic and antithrombotic effects.

ABSTRACT:

Typical omega 3 polyunsaturated fatty acids (n-3 PUFAs) are docosahexaenoic acid and eicosapentaenoic acid in the form of fish oils andα linolenic acid from flaxseed oil. Epidemiological studies suggested the benefits of n-3 PUFA on cardiovascular health. Intervention studies confirmed that the consumption of n-3 PUFA provided benefits for primary and secondary prevention of cardiovascular disease. Evidence from cellular and molecular research studies indicates that the cardioprotective effects of n-3 PUFA result from a synergism between multiple, intricate mechanisms that involve anti-inflammation, proresolving lipid mediators, modulation of cardiac ion channels, reduction of triglycerides, influence on membrane microdomains and downstream cell signaling pathways and antithrombotic and antiarrhythmic effects. n-3 PUFAs inhibit inflammatory signaling pathways (nuclear factor-κ B activity) and down-regulate fatty acid (FA) synthesis gene expression (sterol regulatory element binding protein-1c) and up-regulate gene expression involved in FA oxidation (peroxisome proliferator-activated receptor α). This review examines the various mechanisms by which n-3 PUFA exert beneficial effects against CVD. (Author’s abstract)