Japanese researchers say that eicosapentaenoic acid (EPA), found naturally in fish oil, could might cut heart attack rates by an additional 19%
when given to patients on the cholesterol-lowering drugs.
Primary and secondary prevention trials have already 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. And EPA and its fish oil fatty acid cousin DHA, have both been shown in previous studies to reduce the risk of death from heart disease.
However, no major long-term interventional trial had yet examined whether the addition of EPA to conventional statin treatment could provide additional benefits. So researchers at Kobe University Graduate School of Medicine in Japan studied the effect of EPA in hypercholesterolaemic patients receiving statins for nearly five years as part of the Japan EPA Lipid Intervention Study (JELIS). The new research involved more than 18,600 patients with an average age of 61.
The team reports in The Lancet that in addition to the 19% relative reduction in major coronary events, patients taking EPA also had 19% fewer non-fatal events than the controls. This was due to a combined reduction in non-fatal myocardial infarction, unstable angina, and coronary revascularisation. Sudden cardiac and coronary death did not differ between the groups, however.
The authors, led by Dr Mitsuhiro Yokoyama, conclude: “This study shows
that EPA, at a dose of 1,800 mg per day, is a very promising regimen for prevention of major coronary events, especially since EPA seems to act through several biological mechanisms.”
They conceded however, that because the patients studied were exclusively
Japanese, research needed to be carried out further afield. “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,” they said.
The researchers say that the lack of an effect on death rates might be
Explained by the fact that most people in Japan eat large amounts of fish. The effect on death rates of treating patients with EPA might therefore not show up so easily in Japanese populations,
Dr Dariush Mozaffarian of Harvard School of Public Health, said, however,
There was already reason for optimism. “Compared with drugs, invasive procedures, and devices, modest dietary changes are low risk, inexpensive, and widely available.
“The 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," he said. By Michael Day