The JELIS (Japan EPA Lipid Intervention Study) and GISSI (Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto miocardico) studies are significant clinical trials that explored the effects of omega-3 fatty acids on cardiovascular health. Both studies have played a crucial role in understanding how omega-3 fatty acids, particularly EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), influence heart disease risk and outcomes. Here’s an overview of each study with exact figures and a conclusion on their findings.

JELIS Study

• Objective: To assess the effects of EPA omega-3 fatty acid supplementation, in combination with a statin, on cardiovascular events in a large Japanese population with hypercholesterolemia.
• Design: A large-scale, randomized, open-label, blinded endpoint analysis involving 18,645 participants. The subjects were divided into two groups: one received 1,800 mg of EPA daily with a statin, and the control group received a statin only.
• Results:
  • The EPA group showed a 19% relative reduction in the primary endpoint, which was a composite of major coronary events, including sudden cardiac death, fatal and non-fatal myocardial infarction, and other nonfatal events.
  • Notably, there was a significant 53% reduction in unstable angina and a 19% reduction in non-fatal coronary events. However, there was no significant difference in sudden cardiac death or coronary death alone.
• Conclusion: The JELIS trial concluded that the addition of EPA to statin therapy was effective in reducing the incidence of major coronary events among Japanese patients with hypercholesterolemia, particularly among those with a history of coronary artery disease.

GISSI-Prevenzione Study

• Objective: To investigate the effects of omega-3 fatty acids and vitamin E supplementation on the rate of death, non-fatal myocardial infarction, and stroke in patients who had recently experienced a heart attack.
• Design: A randomized, double-blind, placebo-controlled trial involving 11,324 patients. Participants were assigned to one of four groups: omega-3 fatty acids (1 g daily), vitamin E (300 mg daily), both, or neither (placebo).
• Results:
  • The group receiving omega-3 fatty acids had a 20% reduction in the combined endpoint of death, non-fatal myocardial infarction, and stroke.
  • Specifically, there was a 45% reduction in sudden death and a significant reduction in cardiovascular death.
  • Vitamin E supplementation did not produce significant benefits in the prevention of cardiovascular events.
• Conclusion: The GISSI-Prevenzione study provided strong evidence that omega-3 fatty acid supplementation could significantly reduce the incidence of cardiovascular events, particularly sudden death, in patients post-myocardial infarction.

Overall Conclusion

Both the JELIS and GISSI-Prevenzione studies have provided compelling evidence supporting the cardiovascular benefits of omega-3 fatty acid supplementation. The JELIS study highlighted the additive benefits of EPA supplementation alongside statin therapy, particularly for preventing major coronary events. Meanwhile, the GISSI-Prevenzione study underscored the importance of omega-3 fatty acids in reducing mortality and morbidity in post-heart attack patients, emphasizing their role in secondary prevention. These findings suggest that omega-3 fatty acids, particularly when used as part of a comprehensive cardiovascular risk management strategy, can offer significant protective benefits against heart disease.