Omega‐3 Dietary Supplements and the Risk of Cardiovascular Events: A Systematic Review

Abstract

Background: Epidemiologic data suggest that omega-3 fatty acids derived from fish oil reduce cardiovascular disease. The clinical benefit of dietary fish oil supplementation in preventing cardiovascular events in both high and low risk patients is unclear. Objective: To assess whether dietary supplements of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) decrease cardiovascular events across a spectrum of patients. Data Sources: MEDLINE, Embase, the Cochrane Database of Systematic Reviews, and citation review of relevant primary and review articles. Study Selection: Prospective, randomized, placebo-controlled clinical trials that evaluated clinical cardiovascular end points (cardiovascular death, sudden death, and nonfatal cardiovascular events) and all-cause mortality in patients randomized to EPA/DHA or placebo. We only included studies that used dietary supplements of EPA/DHA which were administered for at least 1 year. Data Extraction: Data were abstracted on study design, study size, type and dose of omega-3 supplement, cardiovascular events, all-cause mortality, and duration of follow-up. Studies were grouped according to the risk of cardiovascular events (high risk and moderate risk). Meta-analytic techniques were used to analyze the data. Data Synthesis: We identified 11 studies that included a total of 39 044 patients. The studies included patients after recent myocardial infarction, those with an implanted cardioverter defibrillator, and patients with heart failure, peripheral vascular disease, and hypercholesterolemia. The average dose of EPA/DHA was 1.8 ± 1.2 g/day and the mean duration of follow-up was 2.2 ± 1. The mortality benefit was largely due to the studies which enrolled high risk patients, while the reduction in nonfatal cardiovascular events was noted in the moderate risk patients (secondary prevention only). Meta-regression failed to demonstrate a relationship between the daily dose of omega-3 fatty acid and clinical outcome. Conclusions: Dietary supplementation with omega-3 fatty acids should be considered in the secondary prevention of cardiovascular events.

Similarities and differences between the effects of EPA and DHA on markers of atherosclerosis in human subjects

“…n-3 PUFA can regulate atherosclerosis by modulating plasma concentrations of blood lipids, inflammation and adhesion molecules, lipid peroxidation, plaque formation and stability, platelet aggregation, thrombosis, BP and heart rate (HR). There have been a number of published reports regarding the effects of fish oils (FO) on risk factors for atherosclerosis; these studies have been the topics of a number of recent reviews (18)(19)(20)(21) . We therefore will only summarise the findings with FO and discuss studies with EPA (20 : 5 n-3) and DHA (22 : 6 n-3) in greater detail; studies with FO will be discussed only for risk factors where there are no or limited number of studies with EPA and DHA individually.…”

Metabolism and functional effects of plant-derived omega-3 fatty acids in humans

“…Introduction Epidemiological studies and several randomised control trials (RCTs) demonstrate a positive relationship between consumption of very-long chain (VLC) ω-3 polyunsaturated fatty acids (PUFAs), specifically eicosapentaenoic acid (EPA; 20:5ω-3) and docosahexaenoic acid (DHA; 22:6ω-3), and long term health benefits [1], including a reduction in cardiovascular disease (CVD) morbidity and mortality [2][3][4][5][6][7][8], better visual and neurological development [9] and improvements in inflammatory conditions including arthritis [10] and asthma [11]. However, it is important to note that not all RCTs report reduced mortality in patients with existing CVD when they receive supplemental EPA and DHA [5,12,13].…”

Relationship between Arteriosclerosis Obliterans and the Ratio of Serum Eicosapentaenoic Acid to Arachidonic Acid

“…Recent reports have determined that unsaturated fatty acids can improve CAD. [3][4][5] Therefore, we hypothesized that fatty acids are associated with ASO.…”