What are Omega-3 Fatty Acids? Omega-3 fatty acids are a group of essential polyunsaturated fats that play a crucial role in maintaining overall health and well-being. Alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid are the three main kinds of omega-3 fatty acids (DHA). ALA is primarily found in plant-based sources like flaxseeds, chia seeds, and walnuts, while EPA and DHA are abundant in fatty fish such as salmon, mackerel, and sardines. Fish oil is derived from the tissues of fatty fish and is well-known for its high content of omega-3 fatty acids, particularly DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid).