The omega-3 fatty acid EPA and stroke prevention
The long-chain omega-3 fatty acid EPA (eicosapentaenoic acid 20:5n-3) has recently been investigated for its role in preventing stroke recurrence. Specifically, the effects of EPA on stroke incidence were investigated as part of a large Japanese study known as the JELIS trial (Japan EPA Lipid Intervention Study). Conducted over a 5-year period, the JELIS trial examined the preventive effect of long-term supplementation with 1800 mg/day EPA on major coronary events and stroke in hypercholesterolemic patients in Japan 1. This large trial included over 18,000 individuals 2 (15,000 without existing coronary artery disease and 3,645 with existing coronary artery disease), all between the ages of 40 and 75. All study participants were placed on statin therapy and then randomized in an open-label, endpoint-blinded manner to either an EPA 1800 mg/day group or a control group. The primary endpoint was any major cardiovascular event (sudden death, fatal or non-fatal myocardial infarction, unstable angina, angioplasty, or coronary artery bypass surgery). After a mean follow-up of 4.6 years, it was determined that EPA significantly suppressed the incidence of coronary events (see article "The omega-3 fatty acid EPA and coronary events").
A subanalysis of the JELIS trial was conducted with respect to stroke incidence, to determine whether EPA supplementation reduced the recurrence of stroke 3. The subanalysis examined the effects of EPA on stroke rates in 942 subjects with a history of stroke. Within this subgroup, stroke occurred in 48 (10.5%) of 457 subjects randomized to the no EPA group, and stroke occurred in 33 (6.8%) of 485 subjects randomized to the EPA group. Thus, EPA supplementation reduced the risk of stroke recurrence by 20%. The number needed to treat (i.e., the number of patients that a doctor would need to treat to prevent one stroke) was 27. These results indicate that 1800 mg/day EPA supplementation achieved secondary prevention of stroke in Japanese hypercholesterolemic patients. Furthermore, EPA supplementation did not raise the risk of subarachnoid hemorrhage or cerebral hemorrhage, indicating that EPA supplementation was safe vis-à-vis stroke risk 4.
It should be noted that the JELIS trial population was exclusively Japanese, and this population exhibits a high background consumption of fish. The JELIS trial was the first to examine the particular effects of EPA on stroke recurrence. The results should inspire future studies to investigate the effects of EPA on stroke prevention in other populations.
References
- Yokoyama M, Origasa H, Matsuzaki M, Matsuzawa Y, Saito Y, Ishikawa Y, Oikawa S, Sasaki J, Hishida H, Itakura H, Kita T, Kitabatake A, Nakaya N, Sakata T, Shimada K, Shirato K. Effects of eicosapentaenoic acid on major coronary events in hypercholesterolaemic patients (JELIS): a randomised open-label, blinded endpoint analysis. Lancet 2007;369:1090-1098.
- Matsuzaki M, Yokoyama M, Saito Y, Origasa H, Ishikawa Y, Oikawa S, Sasaki J, Hishida H, Itakura H, Kita T, Kitabatake A, Nakaya N, Sakata T, Shimada K, Shirato K, Matsuzawa Y. Incremental effects of eicosapentaenoic acid on cardiovascular events in statin-treated patients with coronary artery disease. Circ J 2009;73:1283-1290.
- Tanaka K, Ishikawa Y, Yokoyama M, Origasa H, Matsuzaki M, Saito Y, Matsuzawa Y, Sasaki J, Oikawa S, Hishida H, Itakura H, Kita T, Kitabatake A, Nakaya N, Sakata T, Shimada K, Shirato K. Reduction in the recurrence of stroke by eicosapentaenoic acid for hypercholesterolemic patients: subanalysis of the JELIS trial. Stroke 2008;39:2052-2058.
- Harris WS. Substudies of the Japan EPA Lipid Intervention Study (JELIS). Curr Atheroscler Rep 2009;11:399-400.
Key Points
- In a study based on a hypercholesterolemic patient population in Japan, subjects achieved secondary prevention of stroke with EPA.
- In Japanese hypercholesterolemic patients with a history of stroke, EPA supplementation reduced the risk of stroke recurrence by 20%.
- Further studies must be conducted with EPA to further understand potential benefits of EPA in stroke prevention.
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