A family of polyunsaturated fatty acids which have a carbon-carbon double bond in the Omega position in common. Three important omega acids in nutrition are linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Omega 3 fatty acids have been shown in clinical studies to lower triglyceride levels and reduce the risk of heart attack in people who have already suffered one.