A Review of EE versus TG fish oil (investigation of modern day omega 3 science)

Recently, two clinical trials have settled the debate of which fish oil form is more bio-available in humans; the ethyl ester (EE) versus the triglyceride (TG) forms. One investigational study was instrumental in making this distinction. The main investigator of this study was Dr. Jorn Dyerberg who is considered the ‘Father’ of omega-3 fatty acid science; he was the first to conduct Inuit studies many years ago which brought omega-3 fats to fame. The recent Dyerberg et al., 2010 study1 was done to demonstrate the differences in absorption levels of plasma EPA and DHA following consumption of either EE or TG fish oil groups. Seventy-two volunteers were split into 6 groups, 4 of which were double blinded and 2 of which were the EE and TG groups. Each group was given approximately the same amount of fish oil 3.1-3.6 grams and then compared to a corn oil fed placebo group. Base line plasma levels of EPA and DHA were measured in cholesterol esters (CE), phospholipids (PL) and triglycerides (TG) and then again at the end of the two week period. The results showed that group taking the fish oil in the EE form had the lowest increase in EPA and DHA. When the dosage was adjusted the results were 76% and 134% for the EE and TG groups respectively.

In another recent study done by Neubronner et al., 20102 a similar comparison was made utilizing a different study design. This study was a double blind placebo controlled trial that randomized 150 subjects in one of three groups; two fish oil groups versus placebo. The two fish oil groups (EE and TG) had the exact amount of combined EPA+DHA per capsule and the total dose per day was 1.68g. The two fish oil groups were compared to a corn oil placebo group and the duration of the study was 6 months. The method of assessment was the Omega-3 index, a unique method of bio-availability that measures the EPA and DHA as a % of the total lipids in RBC membranes. In comparison to the plasma levels measured in the Dyerberg et al., study, this method is even more specific because it can measure EPA +DHA at the level of the tissues. According to the authors of this paper they chose the omega 3 index because it can better determine tissue saturation of omega-3 and can correlate to specific organ tissues like that of cardiac tissue which is good reflection of EPA+DHA levels in the body. The outcome of this study showed a significantly greater incorporation of EPA+DHA in the RBC membranes via TG over EE by more than a 25 percent.

Therefore, in both of the above studies the overall bioavailability of omega-3 fatty acids with equal EPA+DHA in the form of TG was far more effective than EE. Since bioavailability is key to achieving the best possible clinical outcomes it would stand that TG fish oils should be the first choice for practitioners.


  1. J Dyerberg , P Madsen , JM Moller ,I Aardestrup ,EB Schmidt. Bioavailability of marine n-3 fatty acid formations. Prostaglandins Leutkot. Essent. Fatty Acids 83 (2010),137-141.
  2. J Neubronner , JP Schuchardt, G Kressel, M Merkel, C von Schacky and A Hahn. Enhanced increase of omega-3 index in response to long term n-3 fatty acid supplementation from triacylglycerides versus ethyl esters. Eur. J. of Clin. Nutr.(2010),1-8