Long-chain omega-3 fatty acids and cardiovascular health

Abstract

Numerous scientific organisations recommend at least two servings of fatty fish per week for heart health in the general population. They recognise the long-chain omega-3 polyunsaturated fatty acids, eicosapentaenoic and docosahexaenoic acids (EPA and DHA), as the bioactive nutrients in fish and extend recommendations to include supplements of these fatty acids, particularly in people with an increased risk or previous diagnosis of heart disease. Epidemiologic observations and clinical interventions have indicated that diets high in EPA and DHA, through fish intake or supplement use, reduce cardiovascular morbidity and mortality. These longchain fatty acids are known to widely impact tissue function through incorporation in membranes. Studies show that EPA and DHA reduce serum triglycerides, reduce blood pressure and heart rate, and normalise inflammatory responses as well as other mechanisms associated with cardiovascular efficiency and protection. The diversity in design and purpose of recent clinical trials has led to mixed results regarding the impact of EPA and DHA on coronary heart disease, particularly in patients treated with statins and other preventive medications. Of particular concern is the reporting of results from studies which are statistically underpowered. In spite of the diversity and confounders associated with these trials, however, the consumption of EPA and DHA is consistently associated with a reduction in cardiac death. The intake of EPA and DHA is below recommended levels in many developed and underdeveloped countries, and an increase in fatty fish intake or the use of supplements containing EPA and DHA is warranted.