One of the main culprits of a heart attack is atherosclerosis, which is one of the consequences of high blood lipid levels and high blood viscosity.
Omega-3s, especially EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), help decrease triglyceride synthesis in the liver by altering the way the body processes fats. This reduction in triglycerides can lower the overall risk of atherosclerosis.