The American Heart Association recommends consuming both omega-3 fatty acids, found in cold-water fish like salmon and canola oil, and omega-6 fatty acids, found in nuts, seeds and vegetable oils such as corn oil.
Instead, the fishing industry processes them into fish meal and oil to make food pellets for salmon farming and livestock feed - especially for Danish pigs.
Most big studies confirming the cardiovascular benefits of omega-3s have tested either docosahexaenoic acid (DHA), an omega-3 found in salmon, sardines and breast milk, or another fishoil called eicosapentaenoic acid (EPA).