Eicosapentaenoic acid (EPA), found naturally in fish oil, could be additionally cardioprotective for people taking statins to lower cholesterol, according to an Article in this week's issue of The Lancet.
Epidemiological and clinical evidence suggests that the increased intake of long-chain n-3 polyunsaturated fatty acids, especially EPA and docosahexaenoic acid (DHA)-found in fish and fish oil-protects against mortality from coronary artery disease. Primary and secondary prevention trials have proved that cholesterol-lowering treatment with statins reduces the risk of all-cause mortality and major cardiovascular events in patients with a wide range of cholesterol concentrations*. However, no major long-term interventional trial has examined whether the addition of EPA to conventional statin treatment could yield an incremental benefit.
The Japan EPA Lipid Intervention Study (JELIS) tested the hypothesis that long-term use of EPA is effective in the reduction of major coronary events in Japanese hypercholesterolaemic patients given statins**. At average follow-up of 4.6 years, Mitsuhiro Yokoyama (Kobe University Graduate School of Medicine, Japan) and colleagues found a 19% relative reduction in major coronary events in patients taking EPA. Patients taking EPA also had 19% fewer non-fatal events than the controls, due to a combined reduction in non-fatal myocardial infarction, unstable angina, and coronary revascularisation. Sudden cardiac death and coronary death did not differ between the groups***.
The authors conclude: "This study shows that EPA, at a dose of 1800 mg per day, is a very promising regimen for prevention of major coronary events, especially since EPA seems to act through several biological mechanisms. Because our population was exclusively Japanese, we cannot generalise the results to other populations. We need to investigate whether EPA is effective for prevention of major coronary events in hypercholesterolaemic patients without or with coronary artery disease in other countries".
In an accompanying Comment, Dariush Mozaffarian (Harvard Medical School and Harvard School of Public Health, Boston, USA) states: "Compared with drugs, invasive procedures, and devices, modest dietary changes are low risk, inexpensive, and widely available??ŠThe JELIS investigators should be commended, and their efforts should inspire additional clinical trials of the effects of fish oil and other dietary factors and habits on cardiovascular health".
Dr Dariush Mozaffarian, Harvard medical School and Harvard School of Public Health, Boston, USA.
Notes:
*Statins are now established as the first-line treatment for hyperlipidaemia.
**18 645 hypercholesterolaemic patients were randomly assigned either 1.8 g of EPA (fish oil) daily with statin or statin only.
***The benefit of fish or fish-oil consumption for cardiac death is non-linear. In previous studies most risk reduction occurred at modest intake, about 1-2 servings per week of oily fish. In Japan average fish consumption is much higher, thus most of the population is already above the threshold for preventing cardiac death. In any such population, you would expect, low baseline rates of cardiac death, and little further reductions in cardiac death with additional fish-oil consumption.
Contact: Mitsuhiro Yokoyama
Lancet