The three Omega 3's are eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and alpha-linolenic acid (ALA). Omega 3 Fish Oil contains high concentrations of EPA and DHA, the two Omega 3's used directly by the human body. ALA is the plant version of EPA and DHA. Once ingested, ALA is converted by a metabolic process into EPA and DHA to make it available for use within the body. Thus, unlike in the case of fish oil, another step is required in turning plant sourced Omega 3, such as flaxseed oil, into a form that can be utilised.
The main benefits of fish oil appear to lie in the omega-3 fatty acids that it contains. Interestingly, the body does not produce its own omega-3 fatty acids. Nor can the body make omega-3 fatty acids from omega-6 fatty acids, which are common in a Western diet. A lot of research has been done on EPA and DHA, two types of omega-3 acids that are often included in fish oil supplements. Omega-3 fatty acids are also known to fight inflammation and reduce pain and swelling.