All Omega-3s are not Created Equal
It is important to remember that all Omega-3s are not created equal. Three common forms of Omega-3 fatty acids are found in foods. ALA is primarily from flax and a few other plant sources such as soy, walnuts, flaxseed and canola oil, while EPA and DHA are primarily from oily fish such as anchovies, sardines, salmon and mackerel. The highest sources of Omega-3 come from anchovies and sardines.
ALA is different bioactively than EPA and DHA. The Institute of Medicine states that ALA is not known to have any specific functions other than as a precursor to EPA and DHA. However, the conversion rate is very inefficient and will not produce the levels of EPA and DHA believed to offer heart health benefits. (4) The optimal approach for heart health with Omega-3 fatty acids is to consume EPA and DHA via fish consumption and/or supplementation. (8)